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Text File | 1989-04-06 | 148.5 KB | 4,274 lines

--------------------------------------------- The use of -> instead of = signifies that the indicated register or register pair contains a pointer to the specified item --------------------------------------------- INT 05 - PRINT-SCREEN KEY Automatically called by keyboard scanner when print-screen key is pressed. Normally executes routine to print the screen, but may call any routine that can safely be executed from inside the keyboard scanner. Status and result byte for default handler is at address 0050:0000. --------------------------------------------- INT 10 - VIDEO - SET VIDEO MODE AH = 00h AL = mode (graphics mode if graphics resolution listed) text pixel graphic color disp scrn system resol box resoltn page addr 00h = 40x25 8x8 B&W 8 B800 CGA = 40x25 8x14 B&W 8 B800 ATI VIP 01h = 40x25 8x8 16 8 B800 CGA = 40x25 8x14 16 8 B800 ATI VIP 02h = 80x25 8x8 B&W 4 B800 CGA = 80x25 8x8 B&W 8 B800 EGA/MCGA/VGA = 80x25 8x14 B&W 8 B800 ATI VIP 03h = 80x25 8x8 16 4 B800 CGA = 80x25 8x8 16 8 B800 EGA/MCGA/VGA 04h = 40x25 8x8 320x200 4 1 B800 CGA 05h = 40x25 8x8 320x200 4 gray 1 B800 CGA 06h = 80x25 8x8 640x200 B&W 1 B800 CGA 07h = 80x25 9x14 mono 1 B000 MDA/Hercules = 80x25 8 EGA/VGA = 80x25 9x14 mono B000 ATI VIP 08h = 20x25 8x8 160x200 16 B800 PCjr/Tandy 1000 09h = 40x25 8x8 320x200 16 B800 PCjr/Tandy 1000 0Ah = 80x25 8x8 640x200 4 B800 PCjr/Tandy 1000 0Bh = reserved (used internally by EGA BIOS) 0Ch = reserved (used internally by EGA BIOS) 0Dh = 40x25 8x8 320x200 16 8 A000 EGA/VGA 0Eh = 80x25 8x8 640x200 16 4 A000 EGA/VGA 0Fh = 80x25 8x14 640x350 mono 2 A000 EGA/VGA 10h = 80x25 8x14 640x350 4or16 2 A000 EGA/VGA 11h = 80x30 8x16 640x480 mono A000 VGA/MCGA/ATI EGA/ATI VIP 12h = 80x30 8x16 640x480 16 A000 VGA/ATI VIP = 80x30 8x16 640x480 16/64 A000 ATI EGA Wonder 13h = 40x25 8x8 320x200 256 A000 VGA/MCGA/ATI VIP 14h = 80x25 8x8 640x200 Lava Chrome II EGA 15h = 80x25 8x14 640x350 Lava Chrome II EGA 16h = 80x25 8x14 640x350 Lava Chrome II EGA 17h = 80x34 8x14 640x480 Lava Chrome II EGA 18h = 132x44 8x8 mono Tseng Labs EVA = 80x34 8x14 640x480 Lava Chrome II EGA 19h = 132x25 8x14 mono Tseng Labs EVA 1Ah = 132x28 8x13 mono Tseng Labs EVA 22h = 132x44 8x8 Tseng, Ahead 23h = 132x25 6x14 Tseng Labs EVA = 132x25 8x14 Ahead Systems EGA2001 = 132x25 8x8 16 B800 ATI EGA Wonder/ATI VIP 24h = 132x28 6x13 Tseng Labs EVA 25h = 80x60 8x8 640x480 Tseng Labs EVA = 640x480 16 VEGA VGA 26h = 80x60 8x8 Tseng Labs EVA = 80x60 8x8 640x480 Ahead Systems EGA2001 27h = 720x512 16 VEGA VGA = 132x25 8x8 mono B000 ATI EGA Wonder/ATI VIP 28h = ???x??? VEGA VGA 29h = 800x600 16 VEGA VGA 2Dh = 640x350 256 VEGA VGA 2Eh = 640x480 256 VEGA VGA 2Fh = 720x512 256 VEGA VGA 30h = 800x600 256 VEGA VGA = ???x??? B800 AT&T 6300 33h = 132x44 8x8 16 B800 ATI EGA Wonder/ATI VIP 36h = 960x720 16 VEGA VGA 37h = 1024x768 16 VEGA VGA = 132x44 8x8 mono B000 ATI EGA Wonder/ATI VIP 40h = 80x25 8x16 640x400 2 1 B800 AT&T 6300, Compaq Portable = 80x43 VEGA VGA 41h = 640x200 16 1 AT&T 6300 = 132x25 VEGA VGA 42h = 80x25 8x16 640x400 16 AT&T 6300 = 132x43 VEGA VGA 43h = unsupported 640x200 of 640x400 viewport AT&T 6300 = 80x60 VEGA VGA 44h = disable VDC and DEB output AT&T 6300 = 100x60 VEGA VGA 48h = 80x50 8x8 640x400 2 B800 AT&T 6300 49h = 80x30 8x16 640x480 Lava Chrome II EGA 4Dh = 120x25 VEGA VGA 4Eh = 120x43 VEGA VGA 4Fh = 132x25 VEGA VGA 50h = 132x25 9x14 mono Ahead Systems EGA2001 = 80x30 8x16 640x480 16 Paradise EGA-480 = 80x43 mono VEGA VGA = 640x480 mono??? Taxan 565 EGA = 80x34 Lava Chrome II EGA 51h = 80x30 8x16 Paradise EGA-480 = 132x25 mono VEGA VGA = 80x34 8x14 640x480 16 ATI EGA Wonder = 80x30 Lava Chrome II EGA 52h = 132x44 9x8 mono Ahead Systems EGA2001 = 132x43 mono VEGA VGA = 94x29 8x14 752x410 16 ATI EGA Wonder = 80x60 Lava Chrome II EGA 53h = 100x40 8x14 800x560 16 ATI EGA Wonder/ATI VIP = 132x43 Lava Chrome II EGA 54h = 132x43 8x8 Paradise EGA-480 = 132x43 7x9 16/256k B800 Paradise VGA = 132x43 8x9 16/256k B800 Paradise VGA on multisync = 132x43 Taxan 565 EGA = 100x42 8x14 800x600 16 A000 ATI EGA Wonder = 132x25 Lava Chrome II EGA 55h = 132x25 8x14 Paradise EGA-480 = 132x25 7x16 16/256k B800 Paradise VGA = 132x25 8x16 16/256k B800 Paradise VGA on multisync = 132x25 Taxan 565 EGA = 80x66 8x8 16/256k A000 ATI VIP = 94x29 8x14 752x410 Lava Chrome II EGA 56h = 132x43 8x8 3??? 2 B000 NSI Smart EGA+ = 132x43 7x9 4 B000 Paradise VGA = 132x43 8x9 4 B000 Paradisk VGA on multisync = 132x43 mono Taxan 565 EGA 57h = 132x25 8x14 3??? 4 B000 NSI Smart EGA+ = 132x25 7x16 4 B000 Paradise VGA = 132x25 8x16 4 B000 Paradise VGA on multisync = 132x25 mono Taxan 565 EGA 58h = 100x75 8x8 800x600 16/256k A000 Paradise VGA = 80x33 8x14 16 B800 ATI EGA Wonder/ATI VIP 59h = 100x75 8x8 800x600 2 A000 Paradise VGA = 80x66 8x8 16/256k A000 ATI VIP 5Eh = 640x400 256 Paradise VGA,VEGA VGA 5Fh = 640x480 256 Paradise VGA 60h = 80x??? ???x400 Corona/Cordata BIOS v4.10+ = 752x410 VEGA VGA 61h = ???x400 Corona/Cordata BIOS v4.10+ = 720x540 VEGA VGA 62h = 800x600 VEGA VGA 70h = extended mode set (see below) Everex Micro Enhancer EGA 71h = 100x35 8x16 800x600 16of64 A000 NSI Smart EGA+ 74h = 640x400 2 B800 Toshiba 3100 AT&T mode 7Eh = special mode set (see below) Paradise VGA 7Fh = special function set (see below) Paradise VGA 82h = 80x25 B&W AT&T VDC overlay mode * 83h = 80x25 AT&T VDC overlay mode * 86h = 640x200 B&W AT&T VDC overlay mode * C0h = 640x400 2/prog pallet AT&T VDC overlay mode * C4h = disable output AT&T VDC overlay mode * D0h = 640x400 2 B800 DEC VAXmate AT&T mode ??? = 640x225 Z-100 ??? = 640x400 Z-100 * for AT&T VDC overlay modes, BL contains the DEB mode, which may be 06h, 40h, or 44h Note: IBM standard modes do not clear the screen if the high bit of AL is set --------------------------------------------- INT 10 - VIDEO - SET CURSOR CHARACTERISTICS AH = 01h CH bits 0-4 = start line for cursor in character cell bits 5-6 = blink attribute (00=normal, 01=invisible, 10=slow, 11=fast) CL bits 0-4 = end line for cursor in character cell Note: buggy on EGA systems--BIOS remaps cursor shape in 43 line modes, but returns unmapped cursor shape --------------------------------------------- INT 10 - VIDEO - SET CURSOR POSITION AH = 02h DH,DL = row, column (0,0 = upper left) BH = page number 0 in graphics modes 0-3 in modes 2&3 0-7 in modes 0&1 --------------------------------------------- INT 10 - VIDEO - READ CURSOR POSITION AH = 03h BH = page number 0 in graphics modes 0-3 in modes 2&3 0-7 in modes 0&1 Return: DH,DL = row,column CH = cursor start line CL = cursor end line --------------------------------------------- INT 10 - VIDEO - READ LIGHT PEN POSITION (all but PS) AH = 04h Return: AH = 0: light pen switch not activated AH = 1: light pen values in registers DH,DL = row,column of current position CH = raster line (0-199) (EGA) old graphics modes CX = (EGA) raster line (0-nnn) new graphics modes BX = pixel column (0-319 or 0-639) --------------------------------------------- INT 10 - VIDEO - SELECT DISPLAY PAGE AH = 05h AL = 0-7: new page value for modes 0 & 1 0-3: new page value for modes 2 & 3 80h: read CRT/CPU page registers [PCjr only] 81h: set CPU page register to value in BL [PCjr only] 82h: set CRT page register to value in BH [PCjr only] 83h: set both display registers to values in BH, BL [PCjr only] {Corona/Cordata BIOS v4.10+} 00h: set address of graphics bitmap buffer (video modes 60h,61h) BX = segment of buffer 0Fh: get address of graphics bitmap buffer (video modes 60h,61h) Return: BH = CRT page register (if AL >= 80h) BL = CPU page register (if AL >= 80h) DX = segment of graphics bitmap buffer (video modes 60h,61h; AL=0Fh) --------------------------------------------- INT 10 - VIDEO - SCROLL PAGE UP AH = 06h AL = number of lines to scroll window (0 = blank whole window) BH = attributes to be used on blanked lines CH,CL = row,column of upper left corner of window to scroll DH,DL = row,column of lower right corner of window --------------------------------------------- INT 10 - VIDEO - SCROLL PAGE DOWN AH = 07h AL = number of lines to scroll window (0 = blank whole window) BH = attributes to be used on blanked lines CH,CL = row,column of upper left corner of window to scroll DH,DL = row,column of lower right corner of window --------------------------------------------- INT 10 - VIDEO - READ ATTRIBUTES/CHARACTER AT CURSOR POSITION AH = 08h BH = display page Return: AL = character AH = attribute of character (alpha modes) --------------------------------------------- INT 10 - VIDEO - WRITE ATTRIBUTES/CHARACTERS AT CURSOR POS AH = 09h AL = character BH = display page BL = attributes of char (alpha modes) or color (graphics modes) if bit 7 == 1 in graphics mode, character is xor'ed onto screen CX = number of times to write character Note: all characters are displayed, including CR, LF, and BS --------------------------------------------- INT 10 - VIDEO - WRITE CHARACTERS ONLY AT CURSOR POS AH = 0Ah AL = character BH = display page - alpha mode BL = color of character (graphics mode, PCjr only) if bit 7 == 1 in graphics mode, character is xor'ed onto screen CX = number of times to write character (EGA) in graphics modes, replication count in CX works correctly only if all character written are contains on the same row Note: all characters are displayed, including CR, LF, and BS --------------------------------------------- INT 10 - VIDEO - SET COLOR PALETTE AH = 0Bh BH = 0 BL = border color (0-15) (text modes) border color and background color (graphics modes) (EGA) BL = border color (0-15) and high-intensity background color (16-31??? maybe should be high nybble?) BH = 1 BL = palette (0-3) --------------------------------------------- INT 10 - VIDEO - WRITE DOT ON SCREEN AH = 0Ch AL = color of dot (0/1 in mode 6, 0-3 in modes 4 and 5) if bit 7 set, new color will be XORed with current pixel BH = display page (ignored if mode only supports one page) CX = column DX = row Note: only valid in graphics modes --------------------------------------------- INT 10 - VIDEO - READ DOT ON SCREEN AH = 0Dh BH = display page (ignored if mode only supports one page) CX = column DX = row Return: AL = color read Note: only valid in graphics modes --------------------------------------------- INT 10 - VIDEO - WRITE CHARACTER AND ADVANCE CURSOR (TTY WRITE) AH = 0Eh AL = character BH = display page (alpha modes) BL = foreground color (graphics modes) Note: characters 07h (BEL), 08h (BS), 0Ah (LF), and 0Dh (CR) are interpreted and do the expected things --------------------------------------------- INT 10 - VIDEO - GET CURRENT VIDEO MODE AH = 0Fh Return: AH = number of columns on screen AL = current video mode (see INT 10h/AH=00h) BH = current active display page Note: if mode was set with bit 7 set ("no blanking"), the returned mode will also have bit 7 set --------------------------------------------- INT 10 - VIDEO - SET PALETTE REGISTERS (Jr, PS, TANDY 1000, EGA, VGA) AH = 10h AL = subfunction 00h set palette register BL = palette register to set BH = color value to store (on MCGA, only BX = 0712h is supported) 01h set border color register BH = color value to store 02h set all palette registers and overscan ES:DX -> 17-byte list bytes 0-15 = values for palette regs. 0-15 byte 16 = value for border color register --------------------------------------------- INT 10 - VIDEO - TOGGLE INTENSITY/BLINKING BIT (Jr, PS, TANDY 1000, EGA, VGA) AX = 1003h BL = 00h enable intensity = 01h enable blink --------------------------------------------- INT 10 - VIDEO - GET PALETTE REGISTERS (VGA) AH = 10h AL = subfunction 07h read individual palette register BL = palette register number Return: BH = palette register value 08h read overscan (border color) register Return: BH = value 09h read all palette registers and overscan register ES:DX = buffer address (17 bytes) --------------------------------------------- INT 10 - VIDEO - WRITE STRING (AT,XT286,PS,EGA,VGA) AH = 13h AL = mode bit 0: set in order to move cursor after write bit 1: set if string contains alternating characters and attributes BL = attribute if AL bit 1 clear BH = display page number DH,DL = row,column of starting cursor position CX = length of string ES:BP -> start of string Note: recognizes CR, LF, BS, and bell --------------------------------------------- INT 10 - VIDEO - SAVE/RESTORE VIDEO STATE (PS50+,VGA) AH = 1Ch CX = requested states bit 0 video hardware 1 BIOS data areas 2 color registers and DAC state 3-15 reserved AL = 0: return state buffer size Return: BX = number of 64 byte blocks needed 1: save video state ES:BX = buffer address 2: restore video state ES:BX = buffer address of previously saved state Return: AL = 1Ch if function supported --------------------------------------------- INT 10 - Direct Graphics Interface Standard (DGIS) - INQUIRE AVAILABLE DEVICES AX = 6A00h BX = 0 CX = 0 DX = buffer length (may be 0) ES:DI = address of buffer Return: BX = number of bytes stored in buffer CX = bytes required for all descriptions (0 if no DGIS) Note: buffer contains descriptions and addresses of DGIS-compatible display(s) and printer(s) --------------------------------------------- INT 10 - DGIS - REDIRECT CHARACTER OUTPUT AX = 6A01h CX = 0 ES:DI = address of device to send INT 10 output to Return: CX = 0 output could not be redirected else INT 10h output now routed to requested display --------------------------------------------- INT 10 - DGIS - INQUIRE INT 10 OUTPUT DEVICE AX = 6A02h ES:DI = 0:0 Return: ES:DI = 0:0 if current display is non-DGIS else address of the current DGIS INT 10 display --------------------------------------------- INT 10 - VIDEO - SET VIDEO MODE (VEGA EXTENDED EGA/VGA) AX = 6F05h BL = mode (graphics mode if graphics resolution listed) text pixel graphic color disp scrn system resol box resoltn page addr 62h = 800x600 16 VEGA Extended EGA 65h = 1024x768 16 VEGA Extended EGA 66h = 640x400 256 VEGA Extended VGA 67h = 640x480 256 VEGA Extended VGA 68h = 720x540 256 VEGA Extended VGA 69h = 800x600 256 VEGA Extended VGA --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - READ ONE REGISTER AH = F0h BL = register number DX = group index Pointer/data chips 00h CRT Controller (25 reg) 3B4h mono modes, 3D4h color modes 08h Sequencer (5 registers) 3C4h 10h Graphics Controller (9 registers) 3CEh 18h Attribute Controller (20 registers) 3C0h Single registers 20h Miscellaneous Output register 3C2h 28h Feature Control register (3BAh mono modes, 3DAh color modes) 30h Graphics 1 Position register 3CCh 38h Graphics 2 Position register 3CAh Return: BL = data --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - WRITE ONE REGISTER AH = F1h DX = group index (see function F0h) BL = register number BH = value to write Return: BL = data --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - READ REGISTER RANGE AH = F2h CH = starting register number CL = Number of registers (>1) DX = group index 00h CRTC (3B4h mono modes, 3D4h color modes) 08h Sequencer 3C4h 10h Graphics Controller 3CEh 18h Attribute Controller 3C0h ES:BX -> buffer, CL bytes --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - WRITE REGISTER RANGE AH = F3h CH = starting register CL = number of registers (>1) DX = group index 00h CRTC (3B4h mono modes, 3D4h color modes) 08h Sequencer 3C4h 10h Graphics Controller 3CEh 18h Attribute Controller 3C0h ES:BX -> buffer, CL bytes --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - READ REGISTER SET AH = F4h CX = number of registers (>1) ES:BX -> table of records in this format: bytes 1-2 group index Pointer/data chips 00h CRTC (3B4h mono modes, 3D4h color modes) 08h Sequencer 3C4h 10h Graphics Controller 3CEh 18h Attribute Controller 3C0h Single registers 20h Miscellaneous Output register 3C2h 28h Feature Control register (3BAh mono modes, 3DAh color) 30h Graphics 1 Position register 3CCh 38h Graphics 2 Position register 3CAh byte 3 register number (0 for single registers) byte 4 register value --------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - READ REGISTER SET AH = F5h CX = number of registers (>1) ES:BX -> table of records in this format: bytes 1-2 port number Pointer/data chips 00h CRTC (3B4h mono modes, 3D4h color modes) 08h Sequencer 3C4h 10h Graphics Controller 3CEh 18h Attribute Controller 3C0h Single registers 20h Miscellaneous Output register 3C2h 28h Feature Control register (3BAh mono modes, 3DAh color) 30h Graphics 1 Position register 3CCh 38h Graphics 2 Position register 3CAh byte 3 register number (0 for single registers) byte 4 register value -------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - REVERT TO DEFAULT REGISTERS AH = F6h -------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - DEFINE DEFAULT REGISTER TABLE AH = F7h DX = port number Pointer/data chips 00h CRTC (3B4h mono modes, 3D4h color modes) 08h Sequencer 3C4h 10h Graphics Controller 3CEh 18h Attribute Controller 3C0h Single registers 20h Miscellaneous Output register 3C2h 28h Feature Control register (3BAh mono modes, 3DAh color modes) 30h Graphics 1 Position register 3CCh 38h Graphics 2 Position register 3CAh ES:BX address of table of one byte entries, one byte to be written to each register -------------------------------------------- INT 10 - Microsoft Mouse driver EGA support - INTERROGATE DRIVER AH = FAh BX = 0 Return: BX = 0 if mouse driver not present ES:BX -> EGA Register Interface version number, if present: byte 1 = major release number byte 2 = minor release number -------------------------------------------- INT 11 - EQUIPMENT DETERMINATION Return: AX = equipment flag bits 0 diskette installed 1 8087 present 2 mouse installed (PS2 only) 2,3 number of 16K banks of RAM on motherboard (PC only) number of 64K banks of RAM on motherboard (XT only) always = 11 on AT and above 4,5 initial video mode 01 = 40x25 color 10 = 80x25 color 11 = 80X25 IBM monochrome 6,7 number of diskette drives (only if bit 0 = 1) 00 = 1, 01 = 2, 10 = 3, 11 = 4 8 0 = dma present, 1 = no dma on system (PCjr???) 9-11 number of RS232 cards 12 game I/O attached 13 serial printer installed (PCjr) internal modem installed (PC/Convertible) 14,15 number of printers --------------------------------------------- INT 12 - MEMORY SIZE Return: AX = number of contiguous 1K blocks of memory --------------------------------------------- INT 13 - DISK - RESET DISK SYSTEM AH = 00h DL = drive (if bit 7 is set both hard disks and floppy disks reset) --------------------------------------------- INT 13 - DISK - STATUS OF DISK SYSTEM AH = 01h DL = drive (hard disk if bit 7 set) Return: AL = status 00h = successful completion 01h = bad command 02h = address mark not found 03h = write attempted on write-protected disk 04h = sector not found 05h = reset failed (hard disk) 06h = diskette changed 07h = parameter act. failed (hard disk) 08h = DMA overrun (floppy disk) 09h = DMA across 64K boundary 0Ah = bad sector detected (hard disk) 0Bh = bad track detected (hard disk) 0Ch = unsupported track 0Dh = invalid number of sectors on format (hard disk) 0Eh = control data address mark detected (hard disk) 0Fh = DMA arbitration error (hard disk) 10h = bad CRC/ECC 11h = data ECC corrected (hard disk) 20h = controller failure 40h = seek failed 80h = time out AAh = drive not ready (hard disk) BBh = undefined error (hard disk) CCh = write fault (hard disk) E0h = status register error (hard disk) FFh = sense operation failed (hard disk) --------------------------------------------- INT 13 - DISK - READ SECTORS INTO MEMORY AH = 02h AL = number of sectors to read CH = track (for hard disk, bits 8,9 in high bits of CL) CL = sector DH = head DL = drive ES:BX = address of buffer to fill Return: CF set on error AH = status (see AH=1 above) AL = number of sectors read --------------------------------------------- INT 13 - DISK - WRITE SECTORS FROM MEMORY AH = 03h AL = number of sectors to write CH = track (if hard disk, bits 8,9 in high bits of CL) CL = sector (if hard disk, high two bits are high bits of track #) DH = head DL = drive ES:BX = address of buffer Return: CF set on error AH = status (see AH=1 above) AL = number of sectors written --------------------------------------------- INT 13 - DISK - VERIFY SECTORS AH = 04h AL = number of sectors to verify CH = track (for hard disk, bits 8,9 in high bits of CL) CL = sector DH = head DL = drive Return: CF set on error AH = status (see AH=1 above) AL = number of sectors verified --------------------------------------------- INT 13 - FLOPPY - FORMAT TRACK AH = 05h AL = number of sectors to create on this track CH = track CL = sector DH = head DL = drive ES:BX -> array of 4-byte address fields byte 1 = track byte 2 = head byte 3 = sector byte 4 = bytes/sector 0=128, 1=256, 2=512, 3=1024 Return: CF set if error occurred AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - FORMAT TRACK AH = 05h AL = interleave value (XT only) ES:BX = 512-byte format buffer the first 2*(sectors/track) bytes contain F,N for each sector F = 00 for good sector, 80h for bad sector N = sector number CH = cylinder number (bits 8,9 in high bits of CL) CL = sector number DH = head DL = drive Return: AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - FORMAT TRACK AND SET BAD SECTOR FLAGS (XT,PORT) AH = 06h AL = interleave value CH = cylinder number (bits 8,9 in high bits of CL) CL = sector number DH = head DL = drive Return: AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - FORMAT DRIVE STARTING AT GIVEN TRACK (XT,PORT) AH = 07h AL = interleave value (XT only) ES:BX = 512-byte format buffer, see AH=6 above CH = cylinder number (bits 8,9 in high bits of CL) CL = sector number DH = head DL = drive Return: AH = status code (see AH=1 above) --------------------------------------------- INT 13 - DISK - GET CURRENT DRIVE PARAMETERS (XT,AT,XT286,CONV,PS) AH = 08h DL = drive number Return: CF set on error AH = status code (see AH=1 above) BL = drive type (see AH=17h below) (AT/PS2 floppies only) DL = number of consecutive acknowledging drives DH = maximum value for head number CL = maximum value fo sector number CH = maximum value for cylinder number ES:DI = drive parameter table --------------------------------------------- INT 13 - FIXED DISK - INITIALIZE TWO FIXED DISK BASE TABLES (XT,AT,XT286,PS) AH = 09h Return: CF set on error AH = status code (see AH=1 above) INT 41h points to table for drive 0 INT 46h points to table for drive 1 --------------------------------------------- INT 13 - FIXED DISK - READ LONG (XT,AT,XT286,PS) AH = 0Ah DL = drive ID DH = head CH = cylinder (bits 8,9 in high bits of CL) CL = sector ES:BX -> buffer to fill Return: CF set on error AH = status code (see AH=1 above) AL = number of sectors read Note: used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - WRITE LONG (XT,AT,XT286,PS) AH = 0Bh DL = drive ID DH = head CH = cylinder (bits 8,9 in high bits of CL) CL = sector ES:BX -> buffer containing data Return: CF set on error AH = status code (see AH=1 above) AL = number of sectors written Note: used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - SEEK TO CYLINDER (XT,AT,XT286,PS) AH = 0Ch DL = drive ID DH = head CH = cylinder (bits 8,9 in high bits of CL) Return: CF set on error AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - ALTERNATE DISK RESET (XT,AT,XT286,PS) AH = 0Dh DL = drive ID Return: CF set on error AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - READ SECTOR BUFFER (XT,PS) AH = 0Eh ES:BX -> buffer Return: CF set on error AH = status code (see AH=1 above) Notes: transfers controller's sector buffer. No data is read from the drive used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - WRITE SECTOR BUFFER (XT,PS) AH = 0Fh ES:BX -> buffer Return: CF set on error AH = status code (see AH=1 above) Notes: should be called before formatting to initialize the controller's sector buffer. used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - TEST FOR DRIVE READY (XT,AT,XT286,PS) AH = 10h DL = drive ID Return: CF set on error AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - RECALIBRATE DRIVE (XT,AT,XT286,PS) AH = 11h DL = drive ID Return: CF set on error AH = status code (see AH=1 above) --------------------------------------------- INT 13 - FIXED DISK - CONTROLER RAM DIAGNOSTIC (XT,PS) AH = 12h Return: CF set on error AH = status code (see AH=1 above) Note: used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - DRIVE DIAGNOSTIC (XT,PS) AH = 13h Return: CF set on error AH = status code (see AH=1 above) Note: used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - FIXED DISK - CONTROLLER DIAGNOSTICS (XT,AT,XT286,PS) AH = 14h Return: CF set on error AH = status code (see AH=1 above) Note: used for diagnostics only on PS/2 systems --------------------------------------------- INT 13 - DISK - GET TYPE (AT,XT2,XT286,CONV,PS) AH = 15h DL = drive ID Return: CF set on error AH = disk type 0 = disk not there 1 = floppy, no change detection present 2 = floppy with change detection 3 = fixed disk CX:DX = number of 512-byte sectors --------------------------------------------- INT 13 - FLOPPY DISK - CHANGE OF DISK STATUS (AT,XT2,XT286,CONV,PS) AH = 16h DL = drive to check Return: AH = disk change status 0 = no disk change 6 = disk changed --------------------------------------------- INT 13 - DISK - SET TYPE (AT,XT2,XT286,CONV,PS) AH = 17h AL = disk type 00h = no disk 01h = regular disk in regular drive 02h = regular disk in high-capacity drive 03h = high-capacity disk in high-capacity drive 04h = 720K disk in 720K drive DL = drive ID --------------------------------------------- INT 13 - DISK - SET MEDIA TYPE FOR FORMAT (AT model 3x9,XT2,XT286,PS) AH = 18h DL = drive number CH = lower 8 bits of number of tracks CL = sectors per track (bits 0-5) top 2 bits of number of tracks (bits 6,7) Return: AH = 00h requested combination supported 01h function not available 0Ch not supported or drive type unknown 80h there is no disk in the drive ES:DI -> 11-byte parameter table --------------------------------------------- INT 13 - FIXED DISK - PARK HEADS (XT286,PS) AH = 19h DL = drive Return: CF set on error AH = status (see AH=1 above) --------------------------------------------- INT 13 - ESDI FIXED DISK - FORMAT UNIT (PS) AH = 1Ah AL = defect table count CL = format modifiers bit 0: ignore primary defect map bit 1: ignore secondary defect map bit 2: update secondary defect map bit 3: perform surface analysis bit 4: generate periodic interrupt DL = drive ES:BX -> defect table Return: CF set on error AH = status (see AH=1 above) Note: if periodic interrupt selected, INT 15h/AH=0Fh is called after each cylinder is formatted --------------------------------------------- INT 13 - DISK - ??? (PS/2) AH = 1Ch AL = ??? (0Ah one value) Return: ??? Note: used by LLFORMAT.COM on PS/2 50/60 reference disk --------------------------------------------- INT 13 - DISK - ??? (Western Digital "Super BIOS") AH = 20h ??? Return: ??? Note: seems to return some kind of status --------------------------------------------- INT 14 - SERIAL I/O - INITIALIZE USART AH = 00h AL = initializing parameters 7 - 6 - 5 4 - 3 2 1 - 0 -BAUD RATE- PARITY STOP WORD BITS LENGTH 000 110 bd 00 none 0-1 10 - 7 001 150 bd 01 odd 1-2 11 - 8 010 300 bd 11 even 011 600 bd 100 1200 bd 101 2400 bd 110 4800 bd 111 9600 bd (4800 on PCjr) DX = port number (0-3) Return: AH = RS-232 status code bits 0: data ready 1: overrun error 2: parity error 3: framing error 4: break detected 5: transmission buffer register empty 6: transmission shift register empty 7: time out--if set, other bits invalid AL = modem status bits 0: delta Clear-To-Send 1: delta Data-Set-Ready 2: trailing edge of ring detected 3: change in receive line signal detected 4: Clear-To-Send 5: Data-Set-Ready 6: ring detected 7: receive line signal detected --------------------------------------------- INT 14 - FOSSIL (Fido/Opus/Seadog Standard Interface Level) - INITIALIZE AH = 00h AL = initializing parameters 7 - 6 - 5 4 - 3 2 1 - 0 -BAUD RATE- PARITY STOP WORD BITS LENGTH 000 19200 bd 00 none 0-1 10 - 7 001 38400 bd 01 odd 1-2 11 - 8 010 300 bd 11 even 011 600 bd 100 1200 bd 101 2400 bd 110 4800 bd 111 9600 bd (4800 on PCjr) DX = port number (0-3) Return: AH = RS-232 status code bits 0: RDA - input data is available in buffer 1: OVRN - data has been lost 5: THRE - room is available in output buffer 6: TSRE - output buffer empty AL = modem status bits 3: always 1 7: DCD - carrier detect --------------------------------------------- INT 14 - SERIAL I/O - TRANSMIT CHARACTER AH = 01h AL = character DX = port number (0-3) Return: AX = port status (see AH = 00h above) --------------------------------------------- INT 14 - SERIAL I/O - RECEIVE CHARACTER AH = 02h DX = port number (0-3) Return: AL = character received AH = RS-232 status code (see AH = 00h above) Note: will timeout if DSR is not asserted, even if function 03h returns data ready --------------------------------------------- INT 14 - FOSSIL - RECEIVE CHARACTER WITH WAIT AH = 02h DX = port number (0-3) Return: AL = character received AH = 00h --------------------------------------------- INT 14 - SERIAL I/O - GET USART STATUS AH = 03h DX = port number (0-3) Return: AX = port status code (see AH = 00h above) --------------------------------------------- INT 14 - SERIAL I/O - EXTENDED INITIALIZE (CONVERTIBLE,PS) AH = 04h AL = break status 0 if break 1 if no break BH = parity 0 no parity 1 odd parity 2 even parity 3 stick parity odd 4 stick parity even BL = number of stop bits 0: one stop bit 1: two stop bits (1.5 if 5 bit word length) CH = word length 0: 5 bits 1: 6 bits 2: 7 bits 3: 8 bits CL = baud rate 0: 110 1: 150 2: 300 3: 600 4: 1200 5: 2400 6: 4800 7: 9600 8: 19200 DX = port number Return: AX = port status code (see AH = 00h above) --------------------------------------------- INT 14 - FOSSIL - INITIALIZE DRIVER AH = 04h DX = port number optionally BX=4F50h ES:CX = address of byte to be set upon ^C Return: AX = 1954h (if successful) BL = maximum function number supported (excluding 7Eh and above) BH = revision of FOSSIL supported DTR is raised --------------------------------------------- INT 14 - SERIAL I/O - EXTENDED COMMUNICATION PORT CONTROL (CONVERTIBLE,PS) AH = 05h AL = 0 read modem control register Return: BL = modem control register (see below) AH = status AL = 1 write modem control register BL = modem control register bit 0: data terminal ready bit 1: request to send bit 2: OUT1 bit 3: OUT2 bit 4: LOOP bits 5-7 reserved Return: AX = status DX = port number --------------------------------------------- INT 14 - FOSSIL - DEINITIALIZE DRIVER AH = 05h DX = port number Return: none DTR is not affected --------------------------------------------- INT 14 - FOSSIL - RAISE/LOWER DTR AH = 06h DX = port AL = DTR state to be set 00h = lower 01h = raise --------------------------------------------- INT 14 - FOSSIL - RETURN TIMER TICK PARAMETERS AH = 07h Return: AL = timer tick interrupt number AH = ticks per second on interrupt number in AL DX = approximate number of milliseconds per tick --------------------------------------------- INT 14 - FOSSIL - FLUSH OUTPUT BUFFER WAITING TILL ALL OUTPUT IS DONE AH = 08h DX = port number --------------------------------------------- INT 14 - FOSSIL - PURGE OUTPUT BUFFER THROWING AWAY ALL PENDING OUTPUT AH = 09h DX = port number --------------------------------------------- INT 14 - FOSSIL - PURGE INTPUT BUFFER THROWING AWAY ALL PENDING INPUT AH = 0Ah DX = port number --------------------------------------------- INT 14 - FOSSIL - TRANSMIT NO WAIT AH = 0Bh AL = character DX = port number Return: AX = 0000h character not accepted = 0001h character accepted --------------------------------------------- INT 14 - FOSSIL - NON-DESTRUCTIVE READ AHEAD AH = 0Ch DX = port number Return: AX = FFFFh character not available AX = 00xxh character xx available --------------------------------------------- INT 14 - FOSSIL - KEYBOARD READ WITHOUT WAIT AH = 0Dh Return: AX = FFFFh character not available = xxyyh standard IBM-style scan code --------------------------------------------- INT 14 - FOSSIL - KEYBOARD READ WITH WAIT AH = 0Eh Return: AX = xxyyh standard IBM-style scan code --------------------------------------------- INT 14 - FOSSIL - ENABLE/DISABLE FLOW CONTROL AH = 0Fh AL = bit mask describing flow control requested 0: xon/xoff on transmit (watch for xoff while sending) 1: CTS/RTS (CTS on transmit/RTS on receive) 2: reserved 3: xon/xoff on receive (send xoff when buffer near full) 4-7: all 1 DX = port number --------------------------------------------- INT 14 - FOSSIL - EXTENDED ^C/^K CHECKING AND TRANSMIT ON/OFF AH = 10h AL = bit mask 0: enable/disable ^C/^K checking 1: enable/disable the transmitter DX = port number --------------------------------------------- INT 14 - FOSSIL - SET CURRENT CURSOR LOCATION AH = 11h DH = row DL = column Note: this is the same as INT 10/AH=02h --------------------------------------------- INT 14 - FOSSIL - READ CURRENT CURSOR LOCATION AH = 12h Return: DH = row DL = column Note: this is the same as INT 10/AH=03h --------------------------------------------- INT 14 - FOSSIL - SINGLE CHARACTER ANSI WRITE TO SCREEN AH = 13h AL = character --------------------------------------------- INT 14 - FOSSIL - ENABLE OR DISABLE WATCHDOG PROCESSING AH = 14h AL = 01h enable watchdog 00h disable watchdog DX = port number --------------------------------------------- INT 14 - FOSSIL - WRITE CHARACTER TO SCREEN USING BIOS SUPPORT ROUTINES AH = 15h AL = character --------------------------------------------- INT 14 - FOSSIL - INSERT/DELETE FUNCTION FROM TIMER TICK CHAIN AH = 16h AL = function 00h = delete 01h = add ES:DX -> routine to call Return: AX = 0000h successful 0001h unsuccessful --------------------------------------------- INT 14 - FOSSIL - REBOOT SYSTEM AH = 17h AL = method 00h = cold boot 01h = warm boot --------------------------------------------- INT 14 - FOSSIL - READ BLOCK AH = 18h CX = maximum number of characters to transfer DX = port number ES:DI -> user buffer Return: AX = number of characters transfered --------------------------------------------- INT 14 - FOSSIL - WRITE BLOCK AH = 19h CX = maximum number of characters to transfer DX = port number ES:DI -> user buffer Return: AX = number of characters transfered --------------------------------------------- INT 14 - FOSSIL - BREAK BEGIN OR END AH = 1Ah AL = 00h stop sending 'break' 01h start sending 'break' DX = port number --------------------------------------------- INT 14 - FOSSIL - RETURN INFORMATION ABOUT THE DRIVER AH = 1Bh DX = port number CX = size of user buffer ES:DI -> user buffer Return: AX = number of characters transferred Structure = WORD size of structure in bytes BYTE FOSSIL spec driver conforms to BYTE revision level of this specific driver DWORD pointer to ASCII identification string WORD size of the input buffer WORD number of bytes left in buffer WORD size of the output buffer WORD number of bytes left in buffer BYTE width of screen BYTE length of screen BYTE actual baud rate, computer to modem --------------------------------------------- INT 14 - FOSSIL - INSTALL AN EXTERNAL APPLICATION FUNCTION AH = 7Eh AL = code assigned to external application ES:DX -> entry point Return: AX = 1954h BL = code assigned to application (same as input AL) DH = 00h failed 01h successful --------------------------------------------- INT 14 - FOSSIL - REMOVE AN EXTERNAL APPLICATION FUNCTION AH = 7Fh AL = code assigned to external application ES:DX -> entry point Return: AX = 1954h BL = code assigned to application (same as input AL) DH = 00h failed 01h successful --------------------------------------------- Int 15 - SYSTEM - FORMAT UNIT PERIODIC INTERRUPT (PS ESDI drives only) AH = 0Fh AL = phase code 00h reserved 01h surface analysis 02h formatting Return: CF clear if formatting should continue, set if it should terminate Note: called during ESDI drive formatting after each cylinder is completed --------------------------------------------- INT 15 - PRINT.COM - ??? (AT,XT286,PS50+) AH = 20h AL = subfunction 00h ??? 01h ??? 10h setup of SYSREQ routine (OS hook) 11h completion of SYSREQ function (OS hook) Note: AL = 0,1 set or reset some flags which affect what PRINT does when it tries to access the disk --------------------------------------------- INT 15 - SYSTEM - POWER-ON SELF-TEST ERROR LOG (PS50+) AH = 21h AL = subfunction 00h read POST log 01h write POST log BH = device ID BL = error code Return: CF set on error AH = status (00h OK, 01h list full, 80h invalid cmd, 86h unsupported) if function 00h: BX = number of error codes stored ES:DI -> error log Note: the log is a series of words, the first byte of which identifies the error code and the second the device. --------------------------------------------- INT 15 - OS HOOK - KEYBOARD INTERCEPT (AT model 3x9,XT2,XT286,CONV,PS) AH = 4Fh AL = scan code CF set Return: CF set AL = scan code CF clear scan code should not be used Note: Called by INT 9 handler to translate scan codes --------------------------------------------- INT 15 - OS HOOK - DEVICE OPEN (AT,XT2,XT286,PS) AH = 80h BX = device ID CX = process type Return: CF set on error AH = status --------------------------------------------- INT 15 - OS HOOK - DEVICE CLOSE (AT,XT2,XT286,PS) AH = 81h BX = device ID CX = process type Return: CF set on error AH = status --------------------------------------------- INT 15 - OS HOOK - DEVICE PROGRAM TERMINATE (AT,XT2,XT286,PS) AH = 82h BX = device ID Return: CF set on error AH = status Note: closes all devices opened with function 80h --------------------------------------------- INT 15 - SYSTEM - EVENT WAIT (AT,XT286,CONV,PS) AH = 83h AL = subservice 0 = set interval 1 = cancel ES:BX -> event flag (bit 7 set when interval expires) CX:DX = number of microseconds to wait (only accurate to 977 us) Return: CF set if function already busy --------------------------------------------- INT 15 - SYSTEM - READ JOYSTICK (AT,XT2,XT286,PS) AH = 84h DX = subservice 0 get switch settings Return: AL = switch settings (bits 7-4) 1 read joystick inputs Return: AX = A(x) value BX = A(y) value CX = B(x) value DX = B(y) value --------------------------------------------- INT 15 - OS HOOK - SYSTEM REQUEST KEY PRESSED (AT,XT2,XT286,CONV,PS) AH = 85h AL = 0 press = 1 release Return: CF set on error AH = status Note: called by keyboard decode routine --------------------------------------------- INT 15 - SYSTEM - WAIT (AT,XT2,XT286,CONV,PS) AH = 86h CX,DX = number of microseconds to wait (only accurate to 977 us) Return: CF clear: after wait elapses CF set: immediately due to error --------------------------------------------- INT 15 - EXTENDED MEMORY - BLOCK MOVE (AT,XT286,PS) AH = 87h CX = number of words to move ES:SI -> global descriptor table 00h-0Fh zero 10h-11h source segment length in bytes (2*CX-1 or greater) 12h-14h 24-bit linear source address 15h access rights byte (93h) 16h-17h zero 18h-19h destination segment length in bytes (2*CX-1 or greater) 1Ah-1Ch 24-bit linear destination address 1Dh access rights byte (93h) 1Eh-2Fh zero Return: CF set on error AH = status 00h source copied into destination 01h parity error 02h interrupt error 03h address line 20 gating failed --------------------------------------------- INT 15 - EXTENDED MEMORY - GET MEMORY SIZE (AT,XT286,PS) AH = 88h Return: AX = memory size in K --------------------------------------------- INT 15 - SYSTEM - SWITCH TO VIRTUAL MODE (AT,XT286,PS50+) AH = 89h BL = interrupt number of IRQ0 (IRQ1-7 use next 7 interrupts) BH = interrupt number of IRQ8 (IRQ9-F use next 7 interrupts) DS:SI -> GDT for protected mode offset 0h null descriptor 8h GDT descriptor 10h IDT descriptor 18h DS 20h ES 28h SS 30h CS 38h uninitialized, used to build descriptor for BIOS CS CX = offset into protected-mode CS to jump to Return: CF set on error AH = 0FFh error enabling address line 20 --------------------------------------------- INT 15 - OS HOOK - DEVICE BUSY LOOP (AT,XT2,XT286,CONV,PS) AH = 90h AL = type code 00h: disk 01h: diskette 02h: keyboard 03h: PS/2 pointing device 80h: network FCh: disk reset FDh: diskette motor start FEh: printer ES:BX -> request block for type codes 80h through BFh Return: CF set if wait time satisfied CF clear if driver must perform wait Note: type codes are allocated as follows: 00-7F non-reentrant devices; OS must arbitrate access 80-BF reentrant devices; ES:BX points to a unique control block C0-FF wait-only calls, no complementary INT 15/AH=91h call --------------------------------------------- INT 15 - OS HOOK - SET FLAG AND COMPLETE INTERRUPT (AT,XT2,XT286,CONV,PS) AH = 91h AL = type code, see AH=90h above ES:BX -> request block for type codes 80h through BFh Return: AH = 0 --------------------------------------------- INT 15 - SYSTEM - GET CONFIGURATION (XT after 1/10/86,AT mdl 3x9,CONV,XT286,PS) AH = C0h Return: CF set if BIOS doesn't support call ES:BX -> ROM table byte_count dw ? ; number of bytes following model db ? ; PC=ff, XT=fe or fb, PCjr = fd, etc, etc submodel db ? ; distingushes between AT and XT/286, etc. BIOS_rev db ? ; 0 for first release, 1 for 2nd, etc. featbyte db ? ; 80h = DMA channel 3 used by hd BIOS ; 40h = 2nd 8259 installed ; 20h = Real-Time Clock installed ; 10h = INT 15h/AH=4Fh called upon INT 9h ; 8h = wait for external event supported ; 4h = extended BIOS area allocated at 640K ; 2h = bus is Micro Channel instead of PC ; 1h reserved res1 dw 0 res2 dw 0 Note: the 1/10/86 XT BIOS returns an incorrect value for featbyte. --------------------------------------------- INT 15 - SYSTEM - RETURN EXTENDED-BIOS DATA-AREA SEGMENT ADDRESS (PS) AH = C1h Return: CF set on error ES = segment of data area --------------------------------------------- INT 15 - POINTING DEVICE BIOS INTERFACE (PS,DESQview 2.x) AH = C2h AL = subfunction 00h enable/disable BH = 00h disable 01h enable 01h reset Return: BH = device ID 02h set sampling rate BH = 00h 10/second 01h 20/second 02h 40/second 03h 60/second 04h 80/second 05h 100/second 06h 200/second 03h set resolution BH = 00h one count per mm 01h two counts per mm 02h four counts per mm 03h eight counts per mm 04h get type Return: BH = device ID 05h initialize BH = data package size (1 - 8 bytes) 06h get/set scaling factor BH = 00h return device status Return: BL = status bit 0: right button pressed bit 1: reserved bit 2: left button pressed bit 3: reserved bit 4: 0 if 1:1 scaling, 1 if 2:1 scaling bit 5: device enabled bit 6: 0 if stream mode, 1 if remote mode bit 7: reserved CL = resolution (see function 03h) DL = sample rate, reports per second 01h set scaling at 1:1 02h set scaling at 2:1 07h set device handler address ES:BX = user device handler Return: CF set on error AH = status 00h successful 01h invalid function 02h invalid input 03h interface error 04h need to resend 05h no device handler installed -------------------------------------------- INT 15 - ENABLE/DISABLE WATCHDOG TIMEOUT (PS50+) AH = C3h AL = 00h disable 01h enable BX = timer counter Return: CF set on error Note: the watchdog timer generates an NMI --------------------------------------------- INT 15 - PROGRAMMABLE OPTION SELECT (PS50+) AH = C4h AL = 00h return base POS register address 01h enable slot BL = slot number 02h enable adapter Return: CF set on error DX = base POS register address (if function 00h) --------------------------------------------- INT 16 - KEYBOARD - READ CHAR FROM BUFFER, WAIT IF EMPTY AH = 00h Return: AH = scan code AL = character --------------------------------------------- INT 16 - KEYBOARD - CHECK BUFFER, DO NOT CLEAR AH = 01h Return: ZF = 0 character in buffer AH = scan code AL = character ZF = 1 no character in buffer --------------------------------------------- INT 16 - KEYBOARD - GET SHIFT STATUS AH = 02h AL = shift status bits 0 = right shift key depressed 1 = left shift key depressed 2 = CTRL depressed 3 = ALT depressed 4 = SCROLL LOCK active 5 = NUM LOCK active 6 = CAPS LOCK active 7 = INSERT state active --------------------------------------------- INT 16 - KEYBOARD - SET DELAYS (Jr,AT model 339,XT286,PS) AH = 03h AL = subfunction 0 reset typematic (PCjr) 1 increase initial delay (PCjr) 2 increase continuing delay (PCjr) 3 increase both delays (PCjr) 4 turn off typematic (PCjr) 5 Set typematic rate (AT or PS/2) BH = 00 - 03 for delays of 250ms, 500ms, 750ms, or 1s BL = 00 - 1F for typematic rates of 30cps down to 2cps --------------------------------------------- INT 16 - KEYBOARD - KEYCLICK (Jr,CONV) AH = 04h AL = 0 click off 1 click on --------------------------------------------- INT 16 - KEYBOARD - WRITE TO KEYBOARD BUFFER (AT model 339,XT2,XT286,PS) AH = 05h CH = scan code CL = character Return: AL = 1 if buffer full --------------------------------------------- INT 16 - KEYBOARD - GET ENHANCED KEYSTROKE (AT model 339,XT2,XT286,PS) AH = 10h Return: AH = scan code AL = character --------------------------------------------- INT 16 - KEYBOARD - CHECK ENHANCED KEYSTROKE (AT model 339,XT2,XT286,PS) AH = 11h Return: ZF = 0 if keystroke available AH = scan code \ meaningless if ZF = 1 AL = character / ZF = 1 if kbd buffer empty --------------------------------------------- INT 16 - KEYBOARD - GET ENHANCED SHIFT FLAGS (AT model 339,XT2,XT286,PS) AH = 12h Return: AL (same as for AH=02h) bit 7: Ins ON bit 6: CapsLock ON bit 5: NumLock ON bit 4: ScrollLock ON bit 3: Either ALT key down bit 2: Either CTRL key down bit 1: Left shift key down bit 0: Right shift key down AH bit 7: SysReq key down bit 6: CapsLock key down bit 5: NumLock key down bit 4: ScrollLock key down bit 3: Right Alt key down bit 2: Right Ctrl key down bit 1: Left Alt key down bit 0: Right Alt key down --------------------------------------------- INT 17 - PRINTER - OUTPUT CHARACTER AH = 00h AL = character DX = printer port (0-3) Return: AH = status bits 0 = time out 1 = unused 2 = unused 3 = I/O error 4 = selected 5 = out of paper 6 = acknowledge 7 = not busy --------------------------------------------- INT 17 - PRINTER - INITIALIZE AH = 01h DX = printer port (0-3) Return: AH = status (see AH = 00h above) --------------------------------------------- INT 17 - PRINTER - GET STATUS AH = 02h DX = printer port (0-3) Return: AH = status (see AH = 00h above) --------------------------------------------- INT 18 - TRANSFER TO ROM BASIC causes transfer to ROM-based BASIC (IBM-PC) often reboots a compatible; often has no effect at all --------------------------------------------- INT 19 - DISK BOOT causes reboot of disk system (no memory test performed) --------------------------------------------- INT 1A - CLOCK - GET TIME OF DAY AH = 00h Return: CX:DX = clock count AL = 0 if clock was read or written (via AH=0,1) within the current 24-hour period Otherwise, AL > 0 --------------------------------------------- INT 1A - CLOCK - SET TIME OF DAY AH = 01h CX:DX = clock count Return: time of day set --------------------------------------------- INT 1A - CLOCK - READ REAL TIME CLOCK (AT,XT286,CONV,PS) AH = 02h Return: CH = hours in BCD CL = minutes in BCD DH = seconds in BCD --------------------------------------------- INT 1A - CLOCK - SET REAL TIME CLOCK (AT,XT286,CONV,PS) AH = 03h CH = hours in BCD CL = minutes in BCD DH = seconds in BCD DL = 1, if daylight savings; 0 if standard time Return: CMOS clock set --------------------------------------------- INT 1A - CLOCK - READ DATE FROM REAL TIME CLOCK (AT,XT286,CONV,PS) AH = 04h Return: DL = day in BCD DH = month in BCD CL = year in BCD CH = century (19h or 20h) --------------------------------------------- INT 1A - CLOCK - SET DATE IN REAL TIME CLOCK (AT,XT286,CONV,PS) AH = 05h DL = day in BCD DH = month in BCD CL = year in BCD CH = century (19h or 20h) Return: CMOS clock set --------------------------------------------- INT 1A - CLOCK - SET ALARM (AT,XT286,CONV,PS) AH = 06h CH = hours in BCD CL = minutes in BCD DH = seconds in BCD Return: CF set if alarm already set or clock inoperable INT 4Ah will be called when alarm goes off, every 24 hours until reset --------------------------------------------- INT 1A - CLOCK - RESET ALARM (AT,XT286,CONV,PS) AH = 07h Return: alarm disabled --------------------------------------------- INT 1A - CLOCK - SET RTC ACTIVATED POWER ON MODE (CONVERTIBLE) AH = 08h CH = hours in BCD CL = minutes in BCD DH = seconds in BCD --------------------------------------------- INT 1A - CLOCK - READ RTC ALARM TIME AND STATUS (CONV,PS30) AH = 09h Return: CH = hours in BCD CL = minutes in BCD DH = seconds in BCD DL = alarm status 0 alarm not enabled 1 alarm enabled but will not power up system 2 alarm will power up system --------------------------------------------- INT 1A - CLOCK - READ SYSTEM-TIMER DAY COUNTER (XT2,PS) AH = 0Ah Return: CF set on error CX = count of days since Jan 1,1980 --------------------------------------------- INT 1A - CLOCK - SET SYSTEM-TIMER DAY COUNTER (XT2,PS) AH = 0Bh CX = count of days since Jan 1,1980 Return: CF set on error --------------------------------------------- INT 1A - PCjr - SET UP SOUND MULTIPLEXOR AH = 80h AL = 0 source is 8253 channel 2 1 source is cassette input 2 source is I/O channel "Audio IN" 3 source is sound generator chip --------------------------------------------- INT 1A - AT&T 6300 - READ TIME AND DATE AH = FEh Return: BX = day count (1 = Jan 1, 1984) CH = hour CL = minute DH = second DL = hundredths --------------------------------------------- INT 1B - CTRL-BREAK KEY This interrupt is called when the keyboard scanner of the IBM machines detects CTRL and BREAK pressed at the same time. It normally points to a short routine in DOS which sets the Ctrl-C flag, thus invoking INT 23h the next time DOS checks for Ctrl-C. --------------------------------------------- INT 1C - CLOCK TICK This interrupt is called (in the IBM) at the end of each time-update operation by the time-of-day routines. It normally points to an IRET. --------------------------------------------- INT 1D -> 6845 VIDEO INIT TABLES table for modes 0 and 1 \ table for modes 2 and 3 \ each table is 16 bytes long and table for modes 4,5, and 6 / contains values for 6845 registers table for mode 7 / 4 words -- size of video RAM for modes 0/1, 2/3, 4/5, and 6/7 8 bytes -- number of columns in each mode 8 bytes -- video controller mode byte for each mode --------------------------------------------- INT 1E -> DISKETTE PARAMS (BASE TABLE) (Default at F000:EFC7 in PC and most compatibles) DB step rate & head unload times DB head load time & DMA DB motor off time in clock ticks (36 or 37 typical) DB sector size in bytes (0->128, 1->256, 2->512, 3->1024) DB last sector number (8 or 9 typical) DB inter-sector gap size on read/write (42 typical) DB data transfer length (255 typical) DB inter-sector gap size on format (80 typical) DB sector fill on format (F6h typical) DB head-settle time ms (typical 25, 1.10->0, 2.10->15, 3.10->1) DB motor start-up time (1/8 secs) (typical 4, 2.10->2) --------------------------------------------- INT 1F -> GRAPHICS SET 2 (NOT a vector!) pointer to bitmaps for high 128 chars --------------------------------------------- INT 20 - Minix - SEND/RECEIVE MESSAGE AX = process ID of other process BX -> message CX = 1 send 2 receive 3 send&receive Note: the message contains the system call number (numbered as in V7 Unix(tm)) and the call parameters --------------------------------------------- INT 20 - DOS - PROGRAM TERMINATION returns to DOS--identical to INT 21/AH=00h --------------------------------------------- INT 21 - DOS - PROGRAM TERMINATION AH = 00h Return: never --------------------------------------------- INT 21 - DOS - KEYBOARD INPUT AH = 01h Return: AL = character read Note: ^C/^Break are checked, and INT 23h executed if read character is echoed to standard output --------------------------------------------- INT 21 - DOS - DISPLAY OUTPUT AH = 02h DL = character to send to standard output Note: ^C/^Break are checked, and INT 23h executed if pressed --------------------------------------------- INT 21 - DOS - AUX INPUT AH = 03h Return: AL = character read --------------------------------------------- INT 21 - DOS - AUX OUTPUT AH = 04h DL = character to send --------------------------------------------- INT 21 - DOS - PRINTER OUTPUT AH = 05h DL = character to print --------------------------------------------- INT 21 - DOS - DIRECT CONSOLE I/O CHARACTER OUTPUT AH = 06h DL = character <> FFh --------------------------------------------- INT 21 - DOS - DIRECT CONSOLE I/O CHARACTER INPUT AH = 06h DL = 0FFh Return: ZF set = no character ZF clear = character recieved AL = character Notes: Character is echoed to STDOUT if received. ^C/^Break are NOT checked --------------------------------------------- INT 21 - DOS - DIRECT STDIN INPUT, NO ECHO AH = 07h Note: same as function 06h for input but char not echoed --------------------------------------------- INT 21 - DOS - KEYBOARD INPUT, NO ECHO AH = 08h Return: AL = character Note: same as function 07h, but ^C/^Break are checked --------------------------------------------- INT 21 - DOS - PRINT STRING AH = 09h DS:DX = address of string terminated by "$" Note: ^C/^Break checked, and INT 23h called if pressed --------------------------------------------- INT 21 - DOS - BUFFERED KEYBOARD INPUT AH = 0Ah DS:DX = address of buffer Note: first byte of buffer must contain maximum length on entry, second byte contains actual length of previous line which may be recalled with the DOS line-editing commands on return the second byte contains actual length, third and subsequent bytes contain the input line --------------------------------------------- INT 21 - DOS - CHECK STANDARD INPUT STATUS AH = 0Bh Return: AL = FFh if character available 00h if no character Note: ^C/^Break checked, and INT 23h called if pressed --------------------------------------------- INT 21 - DOS - CLEAR KEYBOARD BUFFER AH = 0Ch AL must be 1, 6, 7, 8, or 0Ah. Notes: Flushes all typeahead input, then executes function specified by AL (effectively moving it to AH and repeating the INT 21 call). If AL contains a value not in the list above, the keyboard buffer is flushed and no other action is taken. --------------------------------------------- INT 21 - DOS - DISK RESET AH = 0Dh Note: Flushes all disk buffers. --------------------------------------------- INT 21 - DOS - SELECT DISK AH = 0Eh DL = new default drive number (0 = A, 1 = B, etc.) Return: AL = number of logical drives --------------------------------------------- INT 21 - DOS - OPEN DISK FILE AH = 0Fh DS:DX = address of FCB Return: AL = 00h file found FFh file not found Note: (DOS 3.x) file opened in compatibility mode --------------------------------------------- INT 21 - DOS - CLOSE DISK FILE AH = 10h DS:DX = address of FCB Return: AL = 00h directory update successful FFh file not found in directory --------------------------------------------- INT 21 - DOS - SEARCH FIRST USING FCB AH = 11h DS:DX = address of FCB Return: AL = status 00h file found FFh file not found Note: If file found, FCB is created at DTA address and set up to OPEN or DELETE it. --------------------------------------------- INT 21 - DOS - SEARCH NEXT USING FCB AH = 12h DS:DX = address of FCB Return: AL = status 00h file found FFh file not found Note: If file found, FCB is created at DTA address and set up to OPEN or DELETE it. --------------------------------------------- INT 21 - DOS - DELETE FILE via FCB AH = 13h DS:DX = address of FCB with filename field filled with template for deletion ('?' wildcard allowed) Return: AL = status 00h file found FFh file not found --------------------------------------------- INT 21 - DOS - SEQUENTIAL DISK FILE READ AH = 14h DS:DX = address of FCB Return: AL = status 0 successful read 1 end of file 2 data transfer area too small 3 partial record, EOF --------------------------------------------- INT 21 - DOS - SEQUENTIAL DISK RECORD WRITE AH = 15h DS:DX = address of FCB Return: AL = status 0 successful write 1 disk full 2 data transfer area too small --------------------------------------------- INT 21 - DOS - CREATE A DISK FILE AH = 16h DS:DX = address of FCB Return: AL = status 00h successful creation FFh directory full Note: if file already exists, it is truncated to zero length --------------------------------------------- INT 21 - DOS - RENAME FILE via FCB AH = 17h DS:DX = address of FCB FCB contains new name starting at byte 17h. Return: AL = status 00h file found FFh file not found --------------------------------------------- INT 21 - DOS internal - UNUSED AH = 18h Return: AL = 0 --------------------------------------------- INT 21 - DOS - GET DEFAULT DISK NUMBER AH = 19h Return: AL = current drive number (letter - 'A') --------------------------------------------- INT 21 - DOS - SET DISK TRANSFER AREA ADDRESS AH = 1Ah DS:DX = address of buffer --------------------------------------------- INT 21 - DOS - ALLOCATION TABLE INFORMATION AH = 1Bh Return: DS:BX points to FAT ID byte for default drive DX = number of allocation units on disk AL = number of sectors per allocation unit (cluster) CX = number of bytes per sector --------------------------------------------- INT 21 - DOS - ALLOCATION TABLE INFORMATION FOR SPECIFIC DEVICE AH = 1Ch DL = Drive Number to check Return: DS:BX points to FAT ID byte DX = number of allocation units on disk AL = number of sectors per allocation unit (cluster) CX = number of bytes per sector --------------------------------------------- INT 21 - DOS internal - UNUSED AH = 1Dh Return: AL = 0 --------------------------------------------- INT 21 - DOS internal - UNUSED AH = 1Eh Return: AL = 0 --------------------------------------------- INT 21 - DOS internal - GET DEFAULT DRIVE PARAMETER BLOCK AH = 1Fh Return: AL = 00h No Error FFh Error DS:BX -> drive parameter block Note: for DOS 2.x and 3.x, this just invokes function 32h with DL = 0 --------------------------------------------- INT 21 - DOS internal - UNUSED AH = 20h Return: AL = 0 --------------------------------------------- INT 21 - DOS - RANDOM DISK RECORD READ AH = 21h DS:DX = address of FCB Return: AL = status 0 successful read 1 end of file 2 data transfer area too small 3 partial record, EOF --------------------------------------------- INT 21 - DOS - RANDOM DISK RECORD WRITE AH = 22h DS:DX = address of FCB Return: AL = status (see AH = 21h above) --------------------------------------------- INT 21 - DOS - GET FILE SIZE AH = 23h DS:DX = address of unopened FCB with filename and record size fields initialized Return: AL = status 00h file found FFh file not found Note: FCB's random-record field set to number of records (rounded up) --------------------------------------------- INT 21 - DOS - SET RANDOM RECORD FIELD AH = 24h DS:DX = address of FCB Return: Random Record Field of FCB is set to be same as Current Block and Current Record. Note: FCB must be OPEN already --------------------------------------------- INT 21 - DOS - SET INTERRUPT VECTOR AH = 25h AL = interrupt number DS:DX = new vector to be used for specified interrupt --------------------------------------------- INT 21 - DOS - CREATE PSP AH = 26h DX = Segment number to set up PSP at Return: Current PSP is copied to specified segment Note: new PSP is updated with memory size information; INTs 22h, 23h, 24h taken from interrupt vector table --------------------------------------------- INT 21 - DOS - RANDOM BLOCK READ AH = 27h DS:DX = address of FCB CX = number of records to be read Return: AL = status 0 successful read 1 end of file 2 data transfer area too small 3 partial record, EOF --------------------------------------------- INT 21 - DOS - RANDOM BLOCK WRITE AH = 28h DS:DX = address of FCB CX = number of records to be written if zero, truncate file to current random file position Return: AL = status 0 successful write 1 disk full 2 data transfer area too small --------------------------------------------- INT 21 - DOS - PARSE FILENAME AH = 29h DS:SI -> string to parse ES:DI -> buffer to fill with unopened FCB AL = bit mask to control parsing 0 = 0: parsing stops if file separator found 1: leading separator ignored 1 = 0: drive number in FCB set to default drive if not present in string 1: drive number in FCB not changed 2 = 0: filename in FCB set to blanks if no filename in string 1: filename in FCB not changed if string does not contain a filename 3 = 0: extension in FCB set to blanks if no extension in string 1: extension left unchanged Return: AL = 00h: no wildcards in name or extension 01h: wildcards appeared FFh: drive specifier invalid DS:SI -> first byte after parsed string ES:DI buffer filled with unopened FCB --------------------------------------------- INT 21 - DOS - GET CURRENT DATE AH = 2Ah Return: DL = day DH = month CX = year AL = day of the week (0=Sunday, 1=Monday, etc.) --------------------------------------------- INT 21 - DOS - SET CURRENT DATE AH = 2Bh DL = day DH = month CX = year Return: AL = 00h if no error = FFh if bad value sent to routine Note: DOS 3.3 also sets CMOS clock --------------------------------------------- INT 21 - DESQview - INSTALLATION CHECK AH = 2Bh AL = subfunction (DV v2.00+) 01h get version Return: BX = version (BH = major, BL = minor) Note: early copies of v2.00 return 0002h 02h get shadow buffer info, and start shadowing Return: BH = rows in shadow buffer BL = columns in shadow buffer DX = segment of shadow buffer 04h get shadow buffer info Return: BH = rows in shadow buffer BL = columns in shadow buffer DX = segment of shadow buffer 05h stop shadowing CX = 4445h ('DE') DX = 5351h ('SQ') Return: AL = FFh if DESQview not installed Note: in DESQview v1.x, there were no subfunctions; this call only identified whether or not DESQview was loaded --------------------------------------------- INT 21 - DOS - GET CURRENT TIME AH = 2Ch Return: CH = hours CL = minutes DH = seconds DL = hundredths of seconds Note: time is updated approximately every 5/100 second --------------------------------------------- INT 21 - DOS - SET CURRENT TIME AH = 2Dh CH = hours CL = minutes DH = seconds DL = hundredths of seconds Return: AL = 00h if no error = FFh if bad value sent to routine Note: DOS 3.3 also sets CMOS clock --------------------------------------------- INT 21 - DOS - SET VERIFY FLAG AH = 2Eh DL = 0 AL = 1 VERIFY on 0 VERIFY off --------------------------------------------- INT 21 - DOS 2+ - GET DISK TRANSFER AREA ADDRESS AH = 2Fh Return: ES:BX = address of DTA --------------------------------------------- INT 21 - DOS 2+ - GET DOS VERSION AH = 30h Return: AL = Major Version number (0 for DOS 1.x) AH = Minor Version number BH = OEM number 00h IBM 16h DEC BL:CX = 24-bit user number --------------------------------------------- INT 21 - DOS 2+ - TERMINATE BUT STAY RESIDENT AH = 31h AL = exit code DX = program size, in paragraphs --------------------------------------------- INT 21 - DOS 2+ internal - GET DRIVE PARAMETER BLOCK AH = 32h DL = drive number 0 = default, 1 = A, etc. Return: AL = 0FFh if invalid drive number, else DS:BX -> drive parameter block. Structure of DOS Drive Parameter Block: Offset Size Description 00h BYTE drive number (0 = A, etc.) 01h BYTE unit number within device driver 02h WORD number of bytes per sector 04h BYTE largest sector number in cluster (one less than sect/clust) 05h BYTE log base two of the cluster size 06h WORD number of reserved (boot) sectors 08h BYTE number of copies of the FAT 09h WORD number of root directory entries 0Bh WORD first data sector on medium 0Dh WORD largest possible cluster number (one more than # data clust) 0Fh BYTE number of sectors in one FAT copy 10h WORD first sector of root directory 12h DWORD address of device driver for this drive 16h BYTE media descriptor byte for medium 17h BYTE FFh indicates block must be rebuilt (DOS 3.x) 00h indicates block accessed 18h DWORD address of next device block, offset = FFFFh indicates last ---DOS 2.x only--- 1Ch WORD starting cluster of current directory (0 = root directory) 1Eh 64 BYTEs ASCIZ current directory path string ---DOS 3.x--- ; this was always: 1Ch WORD = 0 probably unused, values left from before 1Eh WORD = 0FFFFh block was built --------------------------------------------- INT 21 - DOS 2+ - EXTENDED CONTROL-BREAK CHECKING AH = 33h AL = subfunction 00h get state 01h set state DL = 0 for OFF or 1 for ON 02h internal, called by PRINT.COM (DOS 3.1) 05h internal, return boot drive in DL (1=A:) (not in DOS 3.1) Return: DL = current BREAK setting if AL = 00h 0 BREAK=OFF 1 BREAK=ON AL = FFh if error --------------------------------------------- INT 21 - DOS 2+ internal - RETURN CritSectFlag POINTER AH = 34h Return: ES:BX -> 1-byte DOS "Critical Section Flag", also known as InDOS flag Notes: when the critical section flag is nonzero, code within DOS is being executed. It is safe to enter DOS when both the critical section flag and the critical error flag are zero. The critical error flag is the byte after the critical section flag in DOS 2.x, and the byte BEFORE the critical section flag in DOS 3.x (except COMPAQ DOS 3.0, where the critical error flag is located 1AAh bytes BEFORE the critical section flag) --------------------------------------------- INT 21 - DOS 2+ - GET INTERRUPT VECTOR AH = 35h AL = interrupt number Return: ES:BX = value of interrupt vector --------------------------------------------- INT 21 - DOS 2+ - GET DISK SPACE AH = 36h DL = drive code (0 = default, 1 = A, 2 = B, etc.) Return: AX = number of sectors per cluster or 0FFFFh if invalid drive BX = number of available clusters CX = bytes per sector DX = total clusters Note: multiply AX * CX * BX for free space on disk multiply AX * CX * DX for total disk space --------------------------------------------- INT 21 - DOS 2+ internal - SWITCHAR/AVAILDEV AH = 37h AL = subfunction 0 Read switch character (returns current character in DL) 1 Set switch character (specify new character in DL) 2 (DOS 2.x only) Read device availability (as set by function AL=3) 3 (DOS 2.x only) Set device availability, where: DL = 0 means \DEV\ must preceed device names DL <> 0 means \DEV\ need not preceed device names Return: AL = FFh means the value in AL was not in the range 0-3. DL = Switch character (if AL=0 or 1) Device availability flag (if AL=2 or 3) --------------------------------------------- INT 21 - DOS 2+ - GET COUNTRY-DEPENDENT INFORMATION AH = 38h --DOS 2.x-- AL = 0 get current-country info DS:DX = segment:offset of buffer for returned info Return: BX = country code buffer at DS:DX filled as follows: bytes 0-1 = date format 0 = USA mm dd yy 1 = Europe dd mm yy 2 = Japan yy mm dd byte 2 = currency symbol byte 3 = 00h byte 4 = thousands separator char byte 5 = 00h byte 6 = decimal separator char byte 7 = 00h bytes 8-1Fh reserved --DOS 3.x-- AL = 0 for current country AL = 01h thru 0FEh for specific country with code <255 AL = 0FFh for specific country with code >= 255 BX = 16-bit country code DS:DX = segment:offset of buffer for returned info DX = 0FFFFh if setting country code, rather than getting info Return: (if DX <> 0FFFFh) CF set on error AX = error code (02h) CF clear if successful BX = country code DS:DX filled in: WORD date format (see above) 5 BYTEs currency symbol string, ASCIZ BYTE thousands separator char BYTE 00h BYTE decimal separator char BYTE 00h BYTE date separator char BYTE 00h BYTE time separator char BYTE 00h BYTE currency format bit 2 = set if currency symbol replaces decimal pt bit 1 = number of spaces between value and curr sym bit 0 = 0 if currency symbol precedes value 1 if currency symbol follows value BYTE number of digits after decimal in currency BYTE time format bit 0 = 0 if 12-hour clock 1 if 24-hour clock DWORD address of case map routine (FAR CALL, AL = char to map) BYTE data-list separator char BYTE 00h 10 BYTEs reserved --------------------------------------------- INT 21 - DOS 2+ - CREATE A SUBDIRECTORY (MKDIR) AH = 39h DS:DX = address of ASCIZ pathname Return: CF set on error AX = error code (03h,05h) --------------------------------------------- INT 21 - DOS 2+ - REMOVE A DIRECTORY ENTRY (RMDIR) AH = 3Ah DS:DX = address of ASCIZ pathname Return: CF set on error AX = error code (03h,05h,06h,10h) --------------------------------------------- INT 21 - DOS 2+ - CHANGE THE CURRENT DIRECTORY (CHDIR) AH = 3Bh DS:DX = address of ASCIZ directory name Return: CF set on error AX = error code (03h) --------------------------------------------- INT 21 - DOS 2+ - CREATE A FILE WITH HANDLE (CREAT) AH = 3Ch CX = attributes for file bit 0: read-only 1: hidden 2: system 3: volume label 4: reserved, must be zero (directory) 5: archive bit 7: if set, file is shareable under Novell NetWare DS:DX = address of ASCIZ filename Return: CF set on error AX = error code (03h,04h,05h) CF clear if successful AX = file handle --------------------------------------------- INT 21 - DOS 2+ - OPEN DISK FILE WITH HANDLE AH = 3Dh AL = access code 0 = Read Only 1 = Write Only 2 = Read/Write AL bits 7-3 = file-sharing modes (DOS 3.x) bit 7 = inheritance flag, set for no inheritance bits 4-6 = sharing mode 000 compatibility mode 001 exclusive (deny all) 010 write access denied (deny write) 011 read access denied (deny read) 100 full access permitted (deny none) bit 3 = reserved, should be zero DS:DX = address of ASCIZ filename Return: CF set on error AX = error code (01h,02h,03h,04h,05h,0Ch) CF clear if successful AX = file handle --------------------------------------------- INT 21 - DOS 2+ - CLOSE A FILE WITH HANDLE AH = 3Eh BX = file handle Return: CF set on error AX = error code (06h) --------------------------------------------- INT 21 - DOS 2+ - READ FROM FILE WITH HANDLE AH = 3Fh BX = file handle CX = number of bytes to read DS:DX = address of buffer Return: CF set on error AX = error code (05h,06h) CF clear if successful AX = number of bytes read (0 if at EOF before call) --------------------------------------------- INT 21 - DOS 2+ - WRITE TO FILE WITH HANDLE AH = 40h BX = file handle CX = number of bytes to write DS:DX -> buffer Return: CF set on error AX = error code (05h,06h) CF clear if successful AX = number of bytes actually written Note: if CX is zero, no data is written, and the file is truncated or extended to the current position --------------------------------------------- INT 21 - DOS 2+ - DELETE A FILE (UNLINK) AH = 41h DS:DX -> ASCIZ name of file to delete Return: CF set on error AX = error code (02h,05h) --------------------------------------------- INT 21 - DOS 2+ - MOVE FILE READ/WRITE POINTER (LSEEK) AH = 42h AL = method value 0 = offset from beginning of file 1 = offset from present location 2 = offset from end of file BX = file handle CX:DX = offset in bytes Return: CF set on error AX = error code (01h,06h) CF clear if successful DX:AX = new offset --------------------------------------------- INT 21 - DOS 2+ - GET/PUT FILE ATTRIBUTES (CHMOD) AH = 43h AL = 0 = get file attributes 1 = put file attributes CX = file attribute bits 0 = read only 1 = hidden file 2 = system file 3 = volume label 4 = subdirectory 5 = written since backup 8 = shareable (Novell NetWare) DS:DX -> ASCIZ file name Return: CF set on error AX = error code (01h,02h,03h,05h) CX = file attributes on get --------------------------------------------- INT 21 - DOS 2+ - IOCTL - GET DEVICE INFORMATION AX = 4400h BX = file or device handle Return: CF set on error AX = error code CF clear if successful DX = device info If bit 7 set: (character device) bit 0: console input device 1: console output device 2: NUL device 3: CLOCK$ device 4: device is special 5: binary (raw) mode 6: Not EOF 12: network device (DOS 3.x) 14: can process IOCTL control strings (func 2-5) If bit 7 clear: (file) bits 0-5 are block device number 6: file has not been written 12: network device (DOS 3.x) 14: ??? (DOS 3.x) 15: file is remote (DOS 3.x) --------------------------------------------- INT 21 - DOS 2+ - IOCTL - SET DEVICE INFORMATION AX = 4401h BX = device handle DH = 0 DL = device information to set (bits 0-7 from function 0) Return: CF set on error AX = error code --------------------------------------------- INT 21 - DOS 2+ - IOCTL - READ CHARACTER DEVICE CONTROL STRING AX = 4402h BX = device handle CX = number of bytes to read DS:DX -> buffer Return: CF set on error AX = error code CF clear if successful AX = number of bytes read --------------------------------------------- INT 21 - DOS 2+ - IOCTL - WRITE CHARACTER DEVICE CONTROL STRING AX = 4403h BX = device handle CX = number of bytes to write DS:DX -> buffer Return: CF set on error AX = error code CF clear if successful AX = number of bytes written --------------------------------------------- INT 21 - DOS 2+ - IOCTL - READ BLOCK DEVICE CONTROL STRING AX = 4404h BL = drive number (0=default) CX = number of bytes to read DS:DX -> buffer Return: CF set on error AX = error code CF clear if successful AX = number of bytes read --------------------------------------------- INT 21 - DOS 2+ - IOCTL - WRITE BLOCK DEVICE CONTROL STRING AX = 4405h BL = drive number (0=default) CX = number of bytes to write DS:DX -> buffer Return: CF set on error AX = error code CF clear if successful AX = number of bytes written --------------------------------------------- INT 21 - DOS 2+ - IOCTL - GET INPUT STATUS AX = 4406h BX = file or device handle Return: AL = FFh device ready 00h device not ready --------------------------------------------- INT 21 - DOS 2+ - IOCTL - GET OUTPUT STATUS AX = 4407h BX = file or device handle Return: AL = FFh device ready 00h device not ready Note: for DOS 2.x, files are always ready for output --------------------------------------------- INT 21 - DOS 3.x - IOCTL - BLOCK DEVICE CHANGEABLE AX = 4408h BL = drive number (0=default) Return: AX = 00h removable 01h fixed 0Fh invalid drive --------------------------------------------- INT 21 - DOS 3.x - IOCTL - BLOCK DEVICE LOCAL AX = 4409h BL = drive number (0=default) Return: DX = attribute word, bit 12 set if device is remote --------------------------------------------- INT 21 - DOS 3.x - IOCTL - HANDLE LOCAL AX = 440Ah BX = file handle Return: DX = attribute word, bit 15 set if file is remote Note: if file is remote, Novell Advanced NetWare 2.0 returns the number of the file server on which the handle is located in CX --------------------------------------------- INT 21 - DOS 3.x - IOCTL - SET SHARING RETRY COUNT AX = 440Bh CX = delay (default 1) DX = retry count (default 3) Return: CF set on error AX = error code --------------------------------------------- INT 21 - DOS 3.2 - IOCTL - GENERIC AX = 440Ch BX = device handle CH = category code 00h unknown (DOS 3.3) 01h COMn: (DOS 3.3) 03h CON (DOS 3.3) 05h LPTn: CL = function 45h set iteration count 4Ah select code page 4Ch start code-page preparation 4Dh end code-page preparation 65h get iteration count 6Ah query selected code page 6Bh query prepare list DS:DX -> parameter block for CL=45h WORD iteration count for CL=4Ah,4Dh,6Ah WORD length of data WORD code page ID for CL=4Ch WORD flags WORD length of remainder of parameter block WORD number of code pages following N WORDs code page 1,...,N for CL=6Bh WORD length of following data WORD number of hardware code pages N WORDs hardware code pages 1,...,N WORD number of prepared code pages N WORDs prepared code pages 1,...,N Return: CF set on error AX = error code --------------------------------------------- INT 21 - DOS 3.2 - IOCTL - BLOCK DEVICE REQUEST AX = 440Dh BL = drive number (0=default) CH = category code 08h disk drive CL = function 40h set device parameters 41h write logical device track 42h format and verify logical device track 60h get device parameters 61h read logical device track 62h verify logical device track DS:DX -> parameter block for functions 40h, 60h BYTE special functions bit 0 set if function to use current BPB, clear if Device BIOS Parameter Block field contains new default BPB bit 1 set if function to use track layout fields only must be clear if CL=60h bit 2 set if all sectors in track same size (should be set) bits 3-7 reserved BYTE device type 00h 320K/360K disk 01h 1.2M disk 02h 720K disk 03h single-density 8-inch disk 04h double-density 8-inch disk 05h fixed disk 06h tape drive 07h other type of block device WORD device attributes bit 0 set if nonremovable medium bit 1 set if door lock supported bits 2-15 reserved WORD number of cylinders BYTE media type 00h 1.2M disk (default) 01h 320K/360K disk 31 BYTEs device BPB (see function 53h) WORD number of sectors per track (start of track layout field) N word pairs: number,size of each sector in track for functions 41h, 61h BYTE reserved, must be zero WORD number of disk head WORD number of disk cylinder WORD number of first sector to read/write WORD number of sectors DWORD transfer address for functions 42h, 62h BYTE reserved, must be zero WORD number of disk head WORD number of disk cylinder Return: CF set on error AX = error code --------------------------------------------- INT 21 - DOS 3.2 - IOCTL - GET LOGICAL DRIVE MAP AX = 440Eh BL = drive number (0=default) Return: CF set on error AX = error code CF clear if successful AL = 0 block device has only one logical drive assigned 1..26 the last letter used to reference the drive (1=A:,etc) --------------------------------------------- INT 21 - DOS 3.2 - IOCTL - SET LOGICAL DRIVE MAP AX = 440Fh BL = physical drive number (0=default) Return: CF set on error AX = error code Note: maps logical drives to physical drives, similar to DOS's treatment of a single physical floppy drive as both A: and B: --------------------------------------------- INT 21 - DOS 2+ - CREATE DUPLICATE HANDLE (DUP) AH = 45h BX = file handle to duplicate Return: CF set on error AX = error code (04h,06h) CF clear if successful AX = new file handle --------------------------------------------- INT 21 - DOS 2+ - FORCE DUPLICATE HANDLE (FORCDUP,DUP2) AH = 46h BX = existing file handle CX = new file handle Return: CF set on error AX = error code (04h,06h) Note: closes file with handle BX if it is still open --------------------------------------------- INT 21 - DOS 2+ - GET CURRENT DIRECTORY AH = 47h DL = drive (0=default, 1=A, etc.) DS:SI points to 64-byte buffer area Return: CF set on error AX = error code (0Fh) Note: the returned path does not include the initial backslash --------------------------------------------- INT 21 - DOS 2+ - ALLOCATE MEMORY AH = 48h BX = number of 16-byte paragraphs desired Return: CF set on error AX = error code (07h,08h) BX = maximum available CF clear if successful AX = segment of allocated memory block --------------------------------------------- INT 21 - DOS 2+ - FREE MEMORY AH = 49h ES = segment address of area to be freed Return: CF set on error AX = error code (07h,09h) --------------------------------------------- INT 21 - DOS 2+ - ADJUST MEMORY BLOCK SIZE (SETBLOCK) AH = 4Ah ES = segment address of block to change BX = new size in paragraphs Return: CF set on error AX = error code (07h,08h,09h) BX = maximum size possible for the block --------------------------------------------- INT 21 - DOS 2+ - LOAD OR EXECUTE (EXEC) AH = 4Bh AL = subfunction 0 = load and execute program 1 = load but do not execute (internal) 3 = load overlay; do not create PSP DS:DX = filename ES:BX = parameter block AL = 0: WORD segment of environment (0 = use current) DWORD -> command line DWORD -> FCB 1 DWORD -> FCB 2 1: WORD segment of environment (0 = use current) DWORD -> command line DWORD -> FCB 1 DWORD -> FCB 2 DWORD (DOS 3.x) will hold SS:SP on return DWORD (DOS 3.x) will hold entry point (CS:IP) on return 3: WORD segment load address WORD segment relocation factor Return: CF set on error AX = error code (01h,02h,05h,08h,0Ah,0Bh) CF clear if successful if function 1 and DOS 3.x or DESQview, process ID set to new program's PSP; get with function 62h if function 1 and DOS 2.x, new program's initial stack and entry point returned in registers Note: DOS 2.x destroys all registers, including SS:SP Structure of .EXE file header: 00h WORD 4Dh, 5Ah signature (sometimes 5Ah, 4Dh) 02h WORD image size remainder (program size mod 512) 04h WORD file size in pages (program size div 512) 06h WORD number of relocation items 08h WORD header size in paragraphs 0Ah WORD minimum extra paragraphs needed 0Ch WORD maximum extra paragraphs needed 0Eh WORD stack segment 10h WORD stack offset 12h WORD word checksum of entire file 14h DWORD initial CS:IP 18h WORD offset of relocation table 1Ah WORD overlay number --------------------------------------------- INT 21 - DOS 2+ - QUIT WITH EXIT CODE (EXIT) AH = 4Ch AL = exit code Return: never returns --------------------------------------------- INT 21 - DOS 2+ - GET EXIT CODE OF SUBPROGRAM (WAIT) AH = 4Dh Return: AL = exit code of subprogram (functions 31h or 4Ch) AH = circumstance which caused termination 0 = Terminate/abort 1 = Control-C 2 = Hard error 3 = Terminate and stay resident --------------------------------------------- INT 21 - DOS 2+ - FIND FIRST ASCIZ (FIND FIRST) AH = 4Eh CX = search attributes DS:DX -> ASCIZ filename Return: CF set on error AX = error code (02h,12h) [DTA] = data block undocumented fields, 21 bytes total ---PCDOS 3.10--- BYTE drive letter 11 BYTEs search template BYTE search attributes ---DOS 2.x (and DOS 3.x except 3.1???)--- BYTE search attributes BYTE drive letter 11 BYTEs search template ---both 2.x and 3.x--- WORD entry count within directory 4 BYTEs reserved WORD cluster number of parent directory BYTE attribute of file found WORD file time WORD file date DWORD file size 13 BYTEs ASCIZ filename+extension --------------------------------------------- INT 21 - DOS 2+ - FIND NEXT ASCIZ (FIND NEXT) AH = 4Fh [DTA] = data block from last AH = 4Eh/4Fh call Return: CF set on error AX = error code (12h) [DTA] = data block, see AH = 4Eh above --------------------------------------------- INT 21 - DOS 2+ internal - SET PSP SEGMENT AH = 50h BX = segment address of new PSP Note: under DOS 2.xx, this function cannot be invoked inside an INT 28h handler without setting the Critical Error flag --------------------------------------------- INT 21 - DOS 2+ internal - GET PSP SEGMENT AH = 51h Return: BX = current PSP segment Note: under DOS 2.xx, this function cannot be invoked inside an INT 28h handler without setting the Critical Error flag Structure of PSP: 00h 2 BYTEs program exit point 02h WORD memory size in paragraphs 04h BYTE unused 05h 5 BYTEs CP/M entry point 0Ah DWORD terminate address (old INT 22h) 0Eh DWORD break address (old INT 23h) 12h DWORD critical error handler (old INT 24h) 16h WORD parent PSP segment 18h 20 BYTEs DOS 2+ open file table, FFh = unused 2Ch WORD DOS 2+ environment segment 2Eh DWORD DOS 2+ process's SS:SP on entry to last INT 21 call 32h WORD DOS 3.x max open files 36h DWORD DOS 3.x open file table address 38h 24 BYTEs unused by DOS versions <= 3.3 50h 3 BYTEs DOS function dispatcher (FAR routine) 53h 9 BYTEs unused 5Ch 16 BYTEs FCB #1, filled in from first commandline argument 6Ch 20 BYTEs FCB #2, filled in from second commandline argument 80h 128 BYTEs command tail / default DTA buffer --------------------------------------------- INT 21 - DOS 2+ internal - GET LIST OF LISTS AH = 52h Return: ES:BX points to DOS list of lists List of Lists: Bytes Value -2&-1 segment of first memory control block 00h-03h pointer to first DOS Device Control Block (see function 32h) 04h-07h pointer to list of DOS file tables DWORD pointer to next file table WORD number of files in this table 35h bytes per file 00h-01h number of file handles referring to this file 02h access mode (see function 3Dh) 03h-04h ??? 05h-06h device info word (see function 44h/AL=00h) 07h-0Ah pointer to device driver header if character device pointer to DOS Device Control Block if block device (see func 32h for format) 0Bh-0Ch starting cluster of file 0Dh-0Eh file time in packed format 0Fh-10h file date in packed format 11h-14h file size 15h-18h current offset in file 19h-1Ah ??? 1Bh-1Ch last cluster read 1Dh-1Eh number of sector containing directory entry 1Fh offset of directory entry within sector (byte offset/32) 20h-2Ah filename in FCB format (no path, no period, blank-padded) 2Bh-30h unused??? I see 0 always 31h-32h PSP segment of file's owner 33h-34h unused??? I see 0 always 08h-0Bh pointer to CLOCK$ device driver, whether installable or resident 0Ch-0Fh pointer to actual CON: device driver, whether installable or resident -----DOS 2.x 10h number of logical drives in system 11h-12h maximum bytes/block of any block device 13h-16h pointer to first disk buffer 10h bytes control info followed by the 512-byte buffer DWORD pointer to next disk buffer, FFFFh if last 4 BYTEs ??? WORD logical sector number 2 BYTEs ??? DWORD pointer to DOS Device Control Block (see function 32h) 17h Beginning (not a pointer--the real beginning!) of NUL device driver. This is the first device on DOS's linked list of device drivers. -----DOS 3.x 10h-11h maximum bytes/block of any block device 12h-15h pointer to first disk buffer 10h bytes control info per disk buffer, followed by 512-byte buffer DWORD pointer to next disk buffer, FFFFh if last BYTE drive (0=A:) BYTE flags bit 7: ??? bit 6: ??? bit 5: contents may be overwritten if set (buffer not dirty) bit 4: ??? bit 3: sector in data area bit 2: sector in root directory bit 1: sector in FAT bit 0: ??? WORD logical sector number BYTE ??? BYTE ??? DWORD pointer to DOS Device Control Block (see function 32h) WORD unused??? (almost always 0) 16h-19h pointer to array of drive info: 51h bytes per drive, starting with A: ... 00h-42h current path as ASCIZ, starting with 'x:\' 43h ??? I see zero always 44h ??? I see 40h always 45h-48h pointer to DOS Disk Block for this drive 49h-4Ah starting cluster of current dir, 0 = root, -1 never accessed 4Bh-4Ch ??? I see FFFFh always 4Dh-4Eh ??? I see FFFFh always 4Fh-50h ??? I see 2 always 1Ah-1Dh pointer to FCB table (if CONFIG.SYS contains FCBS=) 1Eh-1Fh size of FCB table 20h number of block devices 21h value of LASTDRIVE command in CONFIG.SYS (default 5) 22h Beginning (not a pointer--the real beginning!) of NUL device driver. This is the first device on DOS's linked list of device drivers. device driver header format: DWORD pointer to next driver or -1 if last driver WORD device attributes bit 15 character device if set, block if clear bit 14 IOCTL supported bit 13 output until busy (character device) non-IBM format (block devices) bit 12 reserved bit 11 OPEN/CLOSE/RM calls supported bit 10-5 reserved bit 4 device is special (uses INT 29 for fast console output) bit 3 device is CLOCK bit 2 device is NUL bit 1 device is standard output bit 0 device is standard input WORD device strategy entry point WORD device interrupt entry point 8 BYTEs blank-padded character device name WORD (CD-ROM driver) 0 BYTE (CD-ROM driver) drive letter BYTE (CD-ROM driver) number of units --------------------------------------------- INT 21 - DOS 2+ internal - TRANSLATE BPB AH = 53h --------------------------------------------- INT 21 - DOS 2+ - GET VERIFY FLAG AH = 54h Return: AL = 0 if flag OFF AL = 1 if flag ON --------------------------------------------- INT 21 - DOS 2+ internal - CREATE PSP AH = 55h DX = segment number at which to set up PSP Note: Like func 26h but creates "child" PSP rather than copying existing one. --------------------------------------------- INT 21 - DOS 2+ - RENAME A FILE AH = 56h DS:DX -> ASCIZ old name ES:DI -> ASCIZ new name Return: CF set on error AX = error code (02h,03h,05h,11h Note: allows move between directories on same logical volume (DOS 3.x) allows renaming of directories --------------------------------------------- INT 21 - DOS 2+ - GET FILE'S DATE/TIME AX = 5700h BX = file handle Return: CF set on error AX = error code (01h,06h) CF clear if successful CX = time of last write DX = date of last write --------------------------------------------- INT 21 - DOS 2+ - SET FILE'S DATE/TIME AX = 5701h BX = file handle CX = time to be set DX = date to be set Return: CF set on error AX = error code (01h,06h) --------------------------------------------- INT 21 - DOS 3.x - GET/SET MEMORY ALLOCATION STRATEGY AH = 58h AL = function code 0 = get allocation strategy 1 = set allocation strategy BL = strategy code 0 first fit (use first memory block large enough) 1 best fit (use smallest memory block large enough) 2 last fit (use high part of last usable memory block) Return: CF set on error AX = error code (01h) CF clear if successful AX = strategy code Note: the Set subfunction accepts any value in BL; 2 or greater means last fit. the Get subfunction returns the last value set, so programs should check whether the value is >= 2, not just equal to 2. --------------------------------------------- INT 21 - DOS 3.x - GET EXTENDED ERROR CODE AH = 59h BX = version code (0000 for DOS 3.x) Return: AX = extended error code BH = class of error BL = suggested action code CH = locus (where error occurred) CL, DX, SI, DI, BP, DS, and ES destroyed Error codes: 01h function number invalid 02h file not found 03h path not found 04h too many open files (no handles available) 05h access denied 06h invalid handle 07h memory control block destroyed 08h insufficient memory 09h memory block address invalid 0Ah environment invalid 0Bh format invalid 0Ch access code invalid 0Dh data invalid 0Fh invalid drive 10h attempted to remove current directory 11h not same device 12h no more files 13h disk write-protected 14h unknown unit 15h drive not ready 16h unknown command 17h data error (CRC) 18h bad request structure length 19h seek error 1Ah unknwon media type (non-DOS disk) 1Bh sector not found 1Ch printer out of paper 1Dh write fault 1Eh read fault 1Fh general failure 20h sharing violation 21h lock violation 22h disk change invalid ES:DI -> ASCIZ volume label of required disk 23h FCB unavailable 24h sharing buffer overflow 25h-31h reserved 32h Network request not supported (DOS 3.1 + MS Networks) 33h Remote computer not listening 34h Duplicate name on network 35h Network name not found 36h Network busy 37h Network device no longer exists 38h Network BIOS command limit exceeded 39h Network adapter hardware error 3Ah Incorrect response from network 3Bh Unexpected network error 3Ch Incompatible remote adapter 3Dh Print queue full 3Eh Queue not full 3Fh Not enough space to print file 40h Network name was deleted 41h Network: Access denied 42h Network device type incorrect 43h Network name not found 44h Network name limit exceeded 45h Network BIOS session limit exceeded 46h Temporarily paused 47h Network request not accepted 48h Print/disk redirection paused (DOS 3.1 + MS Networks) 49h-4Fh reserved 50h file exists 51h reserved 52h cannot make directory 53h fail on INT 24h 54h (DOS 3.3) too many redirections 55h (DOS 3.3) duplicate redirection 56h (DOS 3.3) invalid password 57h (DOS 3.3) invalid parameter 58h (DOS 3.3) network write fault Error Classes: 01h out of resource (storage space or I/O channels) 02h temporary situation (file or record lock) 03h authorization (denied access) 04h internal (system software bug) 05h hardware failure 06h system failure (configuration file missing or incorrect) 07h application program error 08h not found 09h bad format 0Ah locked 0Bh media error 0Ch already exists 0Dh unknown Suggested Action: 01h retry 02h delayed retry 03h prompt user to reenter input 04h abort after cleanup 05h immediate abort 06h ignore 07h retry after user intervention Error Locus: 01h unknown or not appropriate 02h block device (disk error) 03h network related 04h serial device (timeout) 05h memory related --------------------------------------------- INT 21 - DOS 3.x - CREATE UNIQUE FILE AH = 5Ah DS:DX -> ASCIZ directory path name ending with a '\' + 13 bytes to receive generated filename CX = file attribute Return: CF set on error AX = error code (03h,05h) CF clear if successful AX = file handle DS:DX -> path name Note: The file created is not truly "temporary". It MUST be removed by the user. --------------------------------------------- INT 21 - DOS 3.x - CREATE NEW FILE AH = 5Bh DS:DX -> ASCIZ directory path name CX = file attribute Return: CF set on error AX = error code (03h,04h,05h,50h) CF clear if successful DS:DX -> path name Note: Unlike function 3Ch, function 5Bh will fail if the file already exists. --------------------------------------------- INT 21 - DOS 3.x - LOCK/UNLOCK FILE ACCESS AH = 5Ch AL = 00h lock 01h unlock BX = file handle CX:DX = starting offset of region to lock SI:DI = size of region to lock Return: CF set on error AX = error code (01h,06h,21h) --------------------------------------------- INT 21 - DOS 3.1 internal - INDIRECT FUNCTION CALL AX = 5D00h DS:DX -> buffer containing register values AX, BX, CX, DX, SI, DI, DS, ES for a call to INT 21h Return: as appropriate for function being called Notes: does not check AH. Out of range values will crash the system --------------------------------------------- INT 21 - DOS 3.1 internal - SYNC??? AX = 5D01h ??? Return: ??? Note: does something to each disk file in the System File Table which has been written to; if remote file, calls INT 2F/AX=1107h seems to update the time stamp of all open files which have been written --------------------------------------------- INT 21 - DOS 3.1 internal - network - ??? AX = 5D02h ??? Return: ??? Note: error unless network is loaded --------------------------------------------- INT 21 - DOS 3.1 internal - network - ??? AX = 5D03h ??? Return: ??? Note: error unless network is loaded --------------------------------------------- INT 21 - DOS 3.1 internal - network - ??? AX = 5D04h ??? Return: ??? Note: error unless network is loaded --------------------------------------------- INT 21 - DOS 3.1 internal - network - ??? AX = 5D05h ??? Return: ES:DI = ??? BX = ??? CX = ??? Note: error unless network is loaded --------------------------------------------- INT 21 - DOS 3.x internal - GET ADDRESS OF CRITICAL ERROR FLAG AX = 5D06h Return: DS:SI -> critical error flag BX = ??? CX = ??? Notes: this call does a lot of other work in addition to returning the pointer setting CritErr flag allows use of functions 50h/51h from INT 28h under DOS 2.x by forcing use of correct stack --------------------------------------------- INT 21 - DOS 3.x internal - ??? AH = 5Dh AL = subfunction 07h: ??? 08h: ??? (used by COMMAND.COM) 09h: ??? (used by COMMAND.COM) Return: ??? Note: in DOS 3.10, these are identical, and call INT 2F/AX=1125h --------------------------------------------- INT 21 - DOS 3.1+ internal - SET EXTENDED ERROR INFORMATION AX = 5D0Ah DS:DX = address of 11-word error information words 0 to 7: values of AX,BX,CX,DX,SI,DI,DS,ES that func 59h will return words 8 to 10: zero (reserved) --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - GET MACHINE NAME AX = 5E00h DS:DX -> buffer for ASCIZ name (16 bytes) Return: CF set on error AX = error code (01h) CH = 0 if name not defined <> 0 defined CL = NETBIOS name number DS:DX -> ASCIZ machine name --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - SET MACHINE NAME AX = 5E01h DS:DX -> ASCIZ name CL = name number CH = ??? --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - SET PRINTER SETUP AX = 5E02h BX = Redirection list index CX = length of setup string (<= 64) DS:SI -> string buffer Return: CF set on error AX = error code (01h) --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - GET PRINTER SETUP AX = 5E03h BX = Redirection list index ES:DI -> string buffer Return: CF set on error AX = error code (01h) CX = length of setup string (<= 64) --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - GET REDIRECTION LIST ENTRY AX = 5F02h BX = Redirection list index DS:SI -> 16 char local device name buffer ES:DI -> 128 char network name buffer Return: CF set on error AX = error code (01h,12h) BH = Device status flag (BIT 0 = 0 if valid) BL = device type (03 if printer, 04 if drive) CX = stored parameter value (user data) Note: DX and BP are destroyed by this call! --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - REDIRECT DEVICE AX = 5F03h BL = device type 03 = printer device 04 = file device CX = stored parameter value DS:SI -> ASCIZ source device name ES:DI -> destination ASCIZ network path + ASCIZ password Return: CF set on error AX = error code (01h,03h,05h,08h) --------------------------------------------- INT 21 - DOS 3.1 + Microsoft Networks - CANCEL REDIRECTION AX = 5F04h DS:SI -> ASCIZ device name or network path Return: CF set on error AX = error code (01h,0Fh) --------------------------------------------- INT 21 - DOS 3.x internal - RESOLVE PATH STRING TO FULLY QUALIFIED PATH STRING AH = 60h DS:SI = relative path string ES:DI = buffer for fully qualified name Return: buffer filled with qualified name; may return error code, unknown. --------------------------------------------- INT 21 - DOS 3.x internal - UNUSED AH = 61h Return: AL = 0 --------------------------------------------- INT 21 - DOS 3.x - GET PSP ADDRESS AH = 62h Return: BX = segment address of PSP --------------------------------------------- INT 21 - DOS 2.25 only - GET LEAD BYTE TABLE AH = 63h AL = subfunction 0 = get system lead byte table 1 = set/clear interim console flag DL = 1/0 to set/clear interim console flag 2 = get interim console flag Return: CF set on error AX = error code DS:SI -> lead byte table (AL = 0) DL = interim console flag (AL = 2) Note: does not preserve any registers other than SS:SP --------------------------------------------- INT 21 - DOS 3.2 internal - ??? AH = 64h AL = subfunction 00h get ??? Return: DL = ??? 01h set ??? DL = ??? 02h get and set ??? DL = new ??? Return: DL = old ??? --------------------------------------------- INT 21 - DOS 3.3 internal - ??? AH = 64h AL = flag 0 ??? non-0 ??? Return: nothing Note: seems to have something to do with the network --------------------------------------------- INT 21 - DOS 3.3 - GET EXTENDED COUNTRY INFORMATION AH = 65h AL = info ID 01h get general internationalization info 02h get pointer to uppercase table 04h get pointer to filename uppercase table 06h get pointer to collating sequence table BX = code page (-1=global code page) DX = country ID (-1=current country) ES:DI -> country information buffer CX = size of buffer (>= 5) Return: CF set on error AX = error code CF clear if succesful CX = size of country information returned ES:DI -> country information: BYTE info ID if info ID == 1 WORD size WORD country ID WORD code page 34 BYTEs see function 38h if info ID == 2 DWORD pointer to uppercase table WORD table size 128 BYTEs uppercase equivalents (if any) of chars 80h-FFh if info ID == 4 DWORD pointer to collating table WORD table size 256 BYTEs values used to sort characters 00h-FFh if info ID == 6 DWORD pointer to filename uppercase table WORD table size 128 BYTEs uppercase equivalents (if any) of chars 80h-FFh --------------------------------------------- INT 21 - DOS 3.3 - GET GLOBAL CODE PAGE TABLE AH = 6601h Return: CF set on error AX = error code CF clear if successful BX = active code page DX = system code page --------------------------------------------- INT 21 - DOS 3.3 - SET GLOBAL CODE PAGE TABLE AX = 6602h BX = active code page 437 US 850 Multilingual 860 Portugal 863 Canada (French) 865 Norway/Denmark DX = system code page (active page at boot time) Return: CF set on error AX = error code --------------------------------------------- INT 21 - DOS 3.3 - SET HANDLE COUNT AH = 67h BX = desired number of handles (max 255) Return: CF set if error (and error code in AX) --------------------------------------------- INT 21 - DOS 3.3 - COMMIT FILE, WRITE ALL BUFFERED DATA TO DISK AH = 68h BX = file handle Return: CF set on error (and error code in AX) Note: if BX <= 20, no action is taken --------------------------------------------- INT 21 - DOS 4.0 internal - GET DISK SERIAL NUMBER AH = 69h AL = subfunction??? 0 DS:DX -> buffer WORD ??? (zero) DWORD disk serial number (binary) 11 BYTEs volume label or "NO NAME " if none present 8 BYTEs FAT type--string "FAT12 " or "FAT16 " Return: buffer filled with appropriate values --------------------------------------------- INT 21 - DOS 4.0 internal - ??? AH = 6Ah ??? Return: ??? --------------------------------------------- INT 21 - DOS 4.0 internal - ??? AH = 6Bh ??? Return: ??? --------------------------------------------- INT 21 - DOS 4.0 - EXTENDED OPEN/CREATE AX = 6C00h BL = open mode as in AL for normal open BH = 0WF00000 W = auto commit on write F = return error rather than doing INT 24h CX = create attribute DL = action if file exists/does not exists bits 7-4 action if file does not exist 0000 fail 0001 create bits 3-0 action if file exists 0000 fail 0001 open 0010 replace/open DH = 0 DS:SI -> ASCIZ file name Return: CF set on error AX = error code CF clear if successful AX = file handle CX = 1 file opened 2 file created 3 file replaced --------------------------------------------- INT 21 - ??? AH = 89h ??? Note: called by Microsoft C 4.0 startup code --------------------------------------------- INT 22 - DOS - TERMINATE ADDRESS FAR (DWORD) address of routine to be executed when program "returns to DOS". Should NEVER be called directly. --------------------------------------------- INT 23 - DOS - CONTROL "C" EXIT ADDRESS Automatically called from keyboard scanner when CTRL-C or CTRL-BREAK is detected. Normally aborts program and returns to DOS, but may be changed. --------------------------------------------- INT 24 - DOS - FATAL ERROR HANDLER ADDRESS Automatically called upon detection of unrecoverable I/O error. Normally points to routine in resident part of COMMAND.COM that prints "Abort, Retry, Ignore?" message and takes the reply, but may be overridden if desired. Provides the following values in registers on entry to interrupt handler: AH: bit 7 = 0 disk I/O error = 1 other error -- if block device, bad FAT -- if char device, code in DI bit 6 unused bit 5 = 1 if Ignore allowed, 0 if not (DOS 3.x) bit 4 = 1 if Retry allowed, 0 if not (DOS 3.x) bit 3 = 1 if Fail allowed, 0 if not (DOS 3.x) bit 2 \ disk area of error 00 = DOS area 01 = FAT bit 1 / 10 = root dir 11 = data area bit 0 = 1 if write, 0 if read AL = drive number if AH bit 7 = 1, otherwise undefined BP:SI = address of device header for which error occurred block device if high bit of BP:[SI+4] set low byte of DI: 00h write-protect error 01h unknown unit 02h drive not ready 03h unknown command 04h data error (bad CRC) 05h bad request structure length 06h seek error 07h unknown media type 08h sector not found 09h printer out of paper 0Ah write fault 0Bh read fault 0Ch general failure 0Dh (DOS 3.x) sharing violation 0Eh (DOS 3.x) lock violation 0Fh (DOS 3.x) invalid disk change 10h (DOS 3.x) FCB unavailable 11h (DOS 3.x) sharing buffer overflow Handler must return AL = 00 ignore error = 01 retry operation = 02 terminate program through INT 22h = 03 fail system call in progress (DOS 3.x) --------------------------------------------- INT 25 - DOS - ABSOLUTE DISK READ (except DOS 4.0/COMPAQ DOS 3.31 >32M partitn) AL = Drive number (0=A, 1=B, etc) DS:BX = Disk Transfer Address (buffer) CX = Number of sectors to read DX = First relative sector to read Return: CF set on error AL = error code issued to INT 24h in low half of DI AH = 80h if attachment failed to respond 40h if seek operation failed 20h if controller failed 10h if data error (bad CRC) 08h if DMA failure 04h if requested sector not found 03h if write-protected disk 02h if bad address mark 01h if bad command Note: ORIGINAL FLAGS ON STACK! May destroy all registers except segment regs --------------------------------------------- INT 25 - DOS 4.0/COMPAQ DOS 3.31 - ABSOLUTE DISK READ (>32M hard-disk partitn) AL = Drive number (0=A, 1=B, etc) CX = FFFFh DS:BX = Packet address DWORD sector number WORD number of sectors to read DWORD transfer address Return: same as above??? Note: partition is potentially >32M (and requires this form of the call) if bit 1 of device attribute word in device driver is set --------------------------------------------- INT 26 - DOS - ABSOLUTE DISK WRITE (except DOS 4.0/COMPAQ DOS 3.31 >32M partn) AL = Drive number (0=A, 1=B, etc) DS:BX = Disk Transfer Address (buffer) CX = Number of sectors to write DX = First relative sector to write Return: CF set on error AL = error code issued to INT 24h in low half of DI AH = same error codes as for INT 25h Note: ORIGINAL FLAGS ON STACK! --------------------------------------------- INT 26 - DOS 4.0/COMPAQ DOS 3.31 - ABSOLUTE DISK WRITE (>32M hard-disk partitn) AL = Drive number (0=A, 1=B, etc) CX = FFFFh DS:BX = Packet address DWORD sector number WORD number of sectors to write DWORD transfer address Return: same as above??? Note: partition is potentially >32M (and requires this form of the call) if bit 1 of device attribute word in device driver is set --------------------------------------------- INT 27 - DOS - TERMINATE BUT STAY RESIDENT CS = current program segment DX = last program byte + 1 Return: never --------------------------------------------- INT 28 - DOS 2+ internal - KEYBOARD BUSY LOOP This interrupt is called from inside the "get input from keyboard" routine in DOS, if and only if it is safe to use INT 21 to access the disk at that time. It is used primarily by the PRINT.COM routines and TSR programs, but any number of other routines could be chained to it by saving the original vector, and calling it with a FAR call (or just JMPing to it) at the end of the new routine. The INT 28h handler may invoke any INT 21h function except functions 00h through 0Ch (and 50h/51h under DOS 2.xx unless DOS CritErr flag is set). Until some program installs its own routine, this interrupt vector simply points to an IRET opcode. --------------------------------------------- INT 29 - DOS 2+ internal - FAST PUTCHAR This interrupt is called from the DOS output routines if output is going to a device rather than a file, and the device driver's attribute word has bit 3 (04h) set to "1". --------------------------------------------- INT 2E - DOS 2+ internal - EXECUTE COMMAND DS:SI -> counted CR-terminated command string The top-level command.com executes the command; all registers are destroyed as in EXEC (INT 21/AH=4Bh). --------------------------------------------- INT 2F - notes AH identifies which program is to handle the interrupt 00h-7Fh reserved for DOS C0h-FFh reserved for applications AL is the function code This is a general mechanism for verifying the presence of a TSR and communicating with it. --------------------------------------------- INT 2F - BMB Compuscience Canada Utilities Interface AH = xx (dynamically assigned based upon a search for a multiplex number which doesn't answer installed) AL = 00h install check ES:DI = EBEB:BEBE Return: AL = 00h - not installed 01h - not installed, no ok to install FFh - installed and is ES:DI=EBEB:BEBE then ES:DI will point to a string 'BMB xxxx' where xxxx is a product name and version --------------------------------------------- INT 32 - reserved --------------------------------------------- INT 33 - MS MOUSE - RESET DRIVER AND READ STATUS AX = 0000h Return: AX = status 0 hardware/driver not installed -1 hardware/driver installed BX = number of buttons -1 two buttons 0 other than two 3 Mouse Systems mouse --------------------------------------------- INT 33 - MS MOUSE - SHOW MOUSE CURSOR AX = 0001h --------------------------------------------- INT 33 - MS MOUSE - HIDE MOUSE CURSOR AX = 0002h Note: multiple calls to hide the cursor will require multiple calls to function 01h to unhide it. --------------------------------------------- INT 33 - MS MOUSE - RETURN POSITION AND BUTTON STATUS AX = 0003h Return: BX = button status bit 0 left button pressed if 1 bit 1 right button pressed if 1 bit 2 middle button pressed if 1 (Mouse Systems mouse) CX = column DX = row --------------------------------------------- INT 33 - MS MOUSE - POSITION MOUSE CURSOR AX = 0004h CX = column DX = row --------------------------------------------- INT 33 - MS MOUSE - RETURN BUTTON PRESS DATA AX = 0005h BX = button 0 left 1 right 2 middle (Mouse Systems mouse) Return: AX = button states bit 0 left button pressed if 1 bit 1 right button pressed if 1 bit 2 middle button pressed if 1 (Mouse Systems mouse) BX = number of times specified button has been pressed since last call CX = column at time specified button was last pressed DX = row at time specified button was last pressed --------------------------------------------- INT 33 - MS MOUSE - RETURN BUTTON RELEASE DATA AX = 0006h BX = button 0 left 1 right 2 middle (Mouse Systems mouse) Return: AX = button states bit 0 left button pressed if 1 bit 1 right button pressed if 1 bit 2 middle button pressed if 1 (Mouse Systems mouse) BX = number of times specified button has been released since last call CX = column at time specified button was last released DX = row at time specified button was last released --------------------------------------------- INT 33 - MS MOUSE - DEFINE HORIZONTAL CURSOR RANGE AX = 0007h CX = minimum column DX = maximum column --------------------------------------------- INT 33 - MS MOUSE - DEFINE VERTICAL CURSOR RANGE AX = 0008h CX = minimum row DX = maximum row --------------------------------------------- INT 33 - MS MOUSE - DEFINE GRAPHICS CURSOR AX = 0009h BX = column of cursor hot spot in bitmap (-16 to 16) CX = row of cursor hot spot (-16 to 16) ES:DX -> bitmap 16 words screen mask 16 words cursor mask each word defines the sixteen pixels of a row, low bit rightmost --------------------------------------------- INT 33 - MS MOUSE - DEFINE TEXT CURSOR AX = 000Ah BX = hardware/software text cursor 0 software CX = screen mask DX = cursor mask 1 hardware CX = start scan line DX = end scan line Note: when the software cursor is selected, the char/attribute data at the current screen position is ANDed with the screen mask and then XORed with the cursor mask --------------------------------------------- INT 33 - MS MOUSE - READ MOTION COUNTERS AX = 000Bh Return: CX = number of mickeys mouse moved horizontally since last call DX = number of mickeys mouse moved vertically Notes: a mickey is the smallest increment the mouse can sense positive values indicate up/right --------------------------------------------- INT 33 - MS MOUSE - DEFINE INTERRUPT SUBROUTINE PARAMETERS AX = 000Ch CX = call mask bit 0 call if mouse moves bit 1 call if left button pressed bit 2 call if left button released bit 3 call if right button pressed bit 4 call if right button released bit 5 call if middle button pressed (Mouse Systems mouse) bit 6 call if middle button released (Mouse Systems mouse) ES:DX = address of FAR routine Note: when the subroutine is called, it is passed the following values: AX = condition mask (same bit assignments as call mask) BX = button state CX = cursor column DX = cursor row DI = horizontal mickey count SI = vertical mickey count --------------------------------------------- INT 33 - MS MOUSE - LIGHT PEN EMULATION ON AX = 000Dh --------------------------------------------- INT 33 - MS MOUSE - LIGHT PEN EMULATION OFF AX = 000Eh --------------------------------------------- INT 33 - MS MOUSE - DEFINE MICKEY/PIXEL RATIO AX = 000Fh CX = number of mickeys per 8 pixels horizontally DX = number of mickeys per 8 pixels vertically --------------------------------------------- INT 33 - MS MOUSE - DEFINE SCREEN REGION FOR UPDATING AX = 0010h CX,DX = X,Y coordinates of upper left corner SI,DI = X,Y coordinates of lower right corner Note: mouse cursor is hidden during updating, and needs to be explicitly turned on again --------------------------------------------- INT 33 - PCMOUSE - SET LARGE GRAPHICS CURSOR BLOCK AX = 0012h BH = cursor width in words CH = rows in cursor BL = horizontal hot spot (-16 to 16) CL = vertical hot spot (-16 to 16) ES:DX -> bit map of screen and cursor maps Return: AX = -1 if successful --------------------------------------------- INT 33 - MS MOUSE - DEFINE DOUBLE-SPEED THRESHOLD AX = 0013h DX = threshold speed in mickeys/second, 0 = default of 64/second Note: if speed exceeds threshold, the cursor's on-screen motion is doubled --------------------------------------------- INT 33 - MS MOUSE - EXCHANGE INTERRUPT SUBROUTINES AX = 0014h ??? --------------------------------------------- INT 33 - MS MOUSE - RETURN DRIVER STORAGE REQUIREMENTS AX = 0015h Return: BX = size of buffer needed to store driver state --------------------------------------------- INT 33 - MS MOUSE - SAVE DRIVER STATE AX = 0016h ES:DX -> buffer for driver state --------------------------------------------- INT 33 - MS MOUSE - RESTORE DRIVER STATE AX = 0017h ES:DX -> buffer containing saved state --------------------------------------------- INT 33 - MS MOUSE - DEFINE DISPLAY PAGE NUMBER AX = 001Dh ??? --------------------------------------------- INT 33 - MS MOUSE - RETURN DISPLAY PAGE NUMBER AX = 001Eh Return: ??? --------------------------------------------- INT 33 - PCMOUSE - GET MSMOUSE STORAGE REQUIREMENTS AX = 0042h Return: AX = FFFFh successful BX = buffer size in bytes for functions 50h and 52h = 0 MSMOUSE not installed = 42h functions 42h, 50h, and 52h not supported --------------------------------------------- INT 33 - PCMOUSE - SAVE MSMOUSE STATE AX = 0050h BX = buffer size ES:DX -> buffer Return: AX = FFFFh if successful --------------------------------------------- INT 33 - PCMOUSE - RESTORE MSMOUSE STATE AX = 0052h BX = buffer size ES:DX -> buffer Return: AX = FFFFh if successful --------------------------------------------- INT 40 - Hard disk - Relocated Floppy Handler (original INT 13h) --------------------------------------------- INT 41 - FIXED DISK PARAMETERS (XT,AT,XT2,XT286,PS except ESDI disks) WORD cylinders BYTE heads WORD starting reduced write current cylinder (XT only, 0 for others) WORD starting write pre-comp cylinder BYTE maximum ECC burst length BYTE control byte bits 0-2: drive option (XT only, 0 for others) bit 3: set if more than 8 heads bit 4: always 0 bit 5: set if manufacturer's defect map on max cylinder+1 bit 6: disable ECC retries bit 7: disable access retries BYTE standard timeout (XT only, 0 for others) BYTE formatting timeout (XT only, 0 for others) BYTE timeout for checking drive (XT only, 0 for others) WORD landing zone (AT/PS2) BYTE sectors/track (AT/PS2) BYTE 0 --------------------------------------------- INT 42 - EGA/VGA/PS - Relocated (by EGA) Video Handler (original INT 10h) --------------------------------------------- INT 42 - Z100 - ??? --------------------------------------------- INT 43 - EGA/VGA/PS - User font table --------------------------------------------- INT 44 - EGA/VGA/CONV/PS - EGA/PCjr fonts, characters 00h to 7Fh --------------------------------------------- INT 44 - Novell NetWare - HIGH-LEVEL LANGUAGE API --------------------------------------------- INT 44 - Z100 - ??? --------------------------------------------- INT 45 - Z100 - ??? --------------------------------------------- INT 46 - Secondary Fixed Disk Params (see INT 41h) (AT,XT286,PS except ESDI) --------------------------------------------- INT 46 - Z100 - ??? --------------------------------------------- INT 47 - reserved --------------------------------------------- INT 48 - PCjr - Cordless Keyboard Translation --------------------------------------------- INT 49 - PCjr - Non-keyboard Scan Code Translation Table --------------------------------------------- INT 4A - AT/CONV/PS - User Alarm Invoked by BIOS when real-time clock alarm occurs --------------------------------------------- INT 4B - reserved --------------------------------------------- INT 4C - reserved --------------------------------------------- INT 4D - reserved --------------------------------------------- INT 4E - reserved --------------------------------------------- INT 4F - reserved --------------------------------------------- INT 50 to 57 - IRQ0-IRQ7 relocated by DESQview --------------------------------------------- INT 50 to 57 - IRQ0-IRQ7 relocated by IBM 3278 emulation control program --------------------------------------------- INT 58 - reserved --------------------------------------------- INT 59 - GSS Computer Graphics Interface (GSS*CGI) DS:DX -> block of 5 array pointers Return: CF set on error AX = error code CF clear if successful AX = return code Note: INT 59 is the means by which GSS*CGI language bindings communicate with GSS*CGI device drivers and the GSS*CGI device driver controller. also used by the IBM Graphic Development Toolkit --------------------------------------------- INT 5A - Cluster adapter BIOS entry address ??? --------------------------------------------- INT 61 - reserved for user interrupt --------------------------------------------- INT 62 - reserved for user interrupt --------------------------------------------- INT 63 - reserved for user interrupt --------------------------------------------- INT 64 - reserved for user interrupt --------------------------------------------- INT 65 - reserved for user interrupt --------------------------------------------- INT 66 - reserved for user interrupt --------------------------------------------- INT 67 - LIM EMS - GET MANAGER STATUS AH = 40h Return: AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested by application Note: this call can be used only after establishing that the EMS driver is in fact present --------------------------------------------- INT 67 - LIM EMS - GET PAGE FRAME SEGMENT AH = 41h Return: AH = 00h function successful BX = segment of page frame AH = error code (see AH=40h above) --------------------------------------------- INT 67 - LIM EMS - GET NUMBER OF PAGES AH = 42h Return: AH = 00h function successful BX = number of unallocated pages DX = total number of pages AH = error code (see AH=40h above) --------------------------------------------- INT 67 - LIM EMS - GET HANDLE AND ALLOCATE MEMORY AH = 43h BX = number of logical pages to allocate Return: AH = status 00h function successful DX = handle 80h internal error 81h hardware malfunction 84h undefined function requested 85h no more handles available 87h more pages requested than physically exist 88h more pages requested than currently available 89h zero pages requested --------------------------------------------- INT 67 - LIM EMS - MAP MEMORY AH = 44h AL = physical page number (0-3) BX = logical page number DX = handle Return: AH = status 00h function successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Ah invalid logical page number 8Bh illegal physical-page number --------------------------------------------- INT 67 - LIM EMS - RELEASE HANDLE AND MEMORY AH = 45h DX = EMM handle Return: AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 86h error in save or restore of mapping context --------------------------------------------- INT 67 - LIM EMS - GET EMM VERSION AH = 46h Return: AH = status 00h successful AL = EMM version number 80h internal error 81h hardware malfunction 84h undefined function requested --------------------------------------------- INT 67 - LIM EMS - SAVE MAPPING CONTEXT AH = 47h DX = handle Return: AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Ch page-mapping hardware state save area is full 8Dh save of mapping context failed --------------------------------------------- INT 67 - LIM EMS - RESTORE MAPPING CONTEXT AH = 48h DX = handle Return: AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Eh restore of mapping context failed --------------------------------------------- INT 67 - LIM EMS - reserved - GET I/O PORT ADDRESSES AH = 49h Note: defined in EMS 3.0, but undocumented in EMS 3.2 --------------------------------------------- INT 67 - LIM EMS - reserved - GET TRANSLATION ARRAY AH = 4Ah Note: defined in EMS 3.0, but undocumented in EMS 3.2 --------------------------------------------- INT 67 - LIM EMS - GET NUMBER OF EMM HANDLES AH = 4Bh Return: AH = status 00h successful BX = number of EMM handles 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested --------------------------------------------- INT 67 - LIM EMS - GET PAGES OWNED BY HANDLE AH = 4Ch DX = EMM handle Return: AH = status 00h successful BX = number of logical pages 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested --------------------------------------------- INT 67 - LIM EMS - GET PAGES FOR ALL HANDLES AH = 4Dh ES:DI -> array to receive information Return: AH = status 00h successful BX = number of active EMM handles array filled with 2-word entries, consisting of a handle and the number of pages allocated to that handle 80h internal error 81h hardware malfunction 84h undefined function requested --------------------------------------------- INT 67 - LIM EMS - GET OR SET PAGE MAP AH = 4Eh AL = 00h if getting mapping registers 01h if setting mapping registers 02h if getting and setting mapping registers at once 03h if getting size of page-mapping array DS:SI -> array holding information (AL=01/02) ES:DI -> array to receive information (AL=00/02) Return: AH = status 00h successful AL = bytes in page-mapping array (subfunction 03h only) array pointed to by ES:DI receives mapping info (AL=00/02) 80h internal error 81h hardware malfunction 84h undefined function requested 8Fh undefined subfunction parameter A3h contents of source array corrupted (EMS 4.0?) Note: this function was designed to be used by multitasking operating systems and should not ordinarily be used by appplication software. --------------------------------------------- INT 67 - LIM EMS 4.0 - GET/SET PARTIAL PAGE MAP AH = 4Fh AL = subfunction 00h get partial page map DS:SI -> structure containing list of segments whose mapping contexts are to be saved ES:DI -> array to receive page map 01h set partial page map DS:SI -> structure containing saved partial page map 02h get size of partial page map BX = number of mappable segments in the partial map to be saved Return: AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested 8Bh one of specified segments is not mappable 8Fh undefined subfunction parameter A3h contents of partial page map corrupted or count of mappable segments exceeds total number of mappable segments in system AL = size of partial page map for subfunction 02h --------------------------------------------- INT 67 - LIM EMS 4.0 - MAP/UNMAP MULTIPLE HANDLE PAGES AH = 50h AL = subfunction 00h 01h DX = handle CX = number of entries in array DS:SI -> mapping array Return: AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Ah one or more logical pages are invalid 8Bh one or more physical pages are invalid 8Fh invalid subfunction --------------------------------------------- INT 67 - LIM EMS 4.0 - REALLOCATE PAGES AH = 51h DX = handle BX = number of pages to be allocated to handle Return: BX = actual number of pages allocated to handle AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 87h more pages requested than present in system 88h more pages requested than currently available --------------------------------------------- INT 67 - LIM EMS 4.0 - GET/SET HANDLE ATTRIBUTES AH = 52h AL = subfunction 00h get handle attributes 01h set handle attributes BL = new attribute (see returned AL) 02h get attribute capability DX = handle Return: AL = attribute (for subfunction 00h) 00h handle is volatile 01h handle is nonvolatile AL = attribute capability (for subfunction 02h) 00h only volatile handles supported 01h both volatile and non-volatile supported AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Fh undefined subfunction 90h undefined attribute type 91h feature not supported --------------------------------------------- INT 67 - LIM EMS 4.0 - GET/SET HANDLE NAME AH = 53h AL = subfunction 00h get handle name ES:DI -> 8-byte handle name array 01h set handle name DS:SI -> 8-byte handle name DX = handle Return: AH = status 00h successful 80h internal error 81h hardware malfunction 83h invalid handle 84h undefined function requested 8Fh undefined subfunction A1h duplicate handle name --------------------------------------------- INT 67 - LIM EMS 4.0 - GET HANDLE DIRECTORY AH = 54h AL = subfunction 00h get handle directory ES:DI -> buffer for handle directory 01h search for named handle DS:SI -> 8-byte name 02h get total number of handles Return: AL = number of entries in handle directory (subfunction 00h) DX = value of named handle (subfunction 01h) BX = total number of handles (subfunction 02h) AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested 8Fh undefined subfunction A0h no such handle name A1h a handle found had no name --------------------------------------------- INT 67 - LIM EMS 4.0 - ALTER PAGE MAP AND JUMP AH = 55h AL = subfunction 00h physical page numbers provided by caller 01h segment addresses provided by caller DX = handle DS:SI -> structure containing map and jump address Return: (at target address unless error) AH = status 00h successful 80h internal error 81h hardware failure 83h invalid handle 84h undefined function requested 8Ah invalid logical page number encountered 8Bh invalid physical page number encountered 8Fh invalid subfunction --------------------------------------------- INT 67 - LIM EMS 4.0 - ALTER PAGE MAP AND CALL AH = 56h AL = subfunction 00h physical page numbers provided by caller DX = handle DS:SI -> structure containing page map and call address 01h segment addresses provided by caller DX = handle DS:SI -> structure containing page map and call address 02h get page map stack space required Return: (if successful, the target address is called. Use a RETF to return and restore mapping context) BX = stack space required (subfunction 02h) AH = status 00h successful 80h internal error 81h hardware failure 83h invalid handle 84h undefined function requested 8Ah invalid logical page number encountered 8Bh invalid physical page number encountered 8Fh undefined subfunction --------------------------------------------- INT 67 - LIM EMS 4.0 - MOVE/EXCHANGE MEMORY REGION AH = 57h AL = subfunction 00h move memory region 01h exchange memory region DS:SI -> structure describing source and destination Return: AH = status 00h successful 80h internal error 81h hardware failure 83h invalid handle 84h undefined function requested 8Ah invalid logical page number encountered 8Fh undefined subfunction 92h successful, but a portion of the source region has been overwritten 93h length of source or destination region exceeds length of region allocated to either source or destination handle 94h conventional and expanded memory regions overlap 95h offset within logical page exceeds size of logical page 96h region length exceeds 1M 97h source and destination EMS regions have same handle and overlap 98h memory source or destination type undefined A2h attempted to wrap around 1M conventional address space --------------------------------------------- INT 67 - LIM EMS 4.0 - GET MAPPABLE PHYSICAL ADDRESS ARRAY AH = 58h AL = subfunction 00h get mappable physical address array ES:DI -> buffer to be filled with array 01h get number of entries in m.p.a. array Return: CX = number of entries in array AH = status 00h successful 80h internal error 81h hardware failure 84h undefined function requested 8Fh undefined subfunction --------------------------------------------- INT 67 - LIM EMS 4.0 - GET EXPANDED MEMORY HARDWARE INFORMATION AH = 59h AL = subfunction 00h get hardware configuration array ES:DI -> buffer to be filled with array 01h get unallocated raw page count Return: BX = unallocated raw pages (subfunction 01h) DX = total raw pages (subfunction 01h) AH = status 00h successful 80h internal error 81h hardware failure 84h undefined function requested 8Fh undefined subfunction A4h access denied by operating system Note: subfunction 00h is for use by operating systems only, and can be enabled or disabled at any time by the operating system --------------------------------------------- INT 67 - LIM EMS 4.0 - ALLOCATE STANDARD/RAW PAGES AH = 5Ah AL = subfunction 00h allocate standard pages 01h allocate raw pages BX = number of pages to allocate Return: DX = handle AH = status 00h successful 80h internal error 81h hardware failure 84h undefined function requested 85h no more handles available 87h insufficient memory pages in system 88h insufficient memory pages available 8Fh undefined subfunction --------------------------------------------- INT 67 - LIM EMS 4.0 - ALTERNATE MAP REGISTER SET AH = 5Bh AL = subfunction 00h get alternate map register set 01h set alternate map register set BL = new alternate map register set number ES:DI -> map register context save area if BL=0 02h get alternate map save array size 03h allocate alternate map register set 04h deallocate alternate map register set BL = number of alternate map register set Return: BL = current active alternate map register set number if nonzero (AL=0) ES:DI -> map register context save area if BL=0 (AL=0) DX = array size in bytes (subfunction 02h) BL = number of alternate map register set; zero if not supported (AL=3) AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested 8Fh undefined subfunction 9Ah specified alternate map register set not supported 9Bh all alternate map register sets currently allocated 9Ch alternate map register sets not supported 9Dh undefined or unallocated alternate map register set A3h source array corrupted A4h operating system denied access Note: this function is for use by operating systems only, and can be enabled or disabled at any time by the operating system --------------------------------------------- INT 67 - LIM EMS 4.0 - ALTERNATE MAP REGISTER SET - DMA REGISTERS AH = 5Bh AL = subfunction 05h allocate DMA register set 06h enable DMA on alternate map register set BL = DMA register set number DL = DMA channel number 07h disable DMA on alternate map register set BL = DMA register set number 08h deallocate DMA register set BL = DMA register set number Return: BL = DMA register set number; zero if not supported (subfunction 05h) AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested 8Fh undefined subfunction 9Ah specified DMA register set not supported 9Bh all DMA register sets currently allocated 9Ch alternate DMA sets not supported 9Dh undefined or unallocated DMA register set 9Eh dedicated DMA channels not supported 9Fh specified dedicated DMA channel not supported A3h source array corrupted A4h operating system denied access Note: this function is for use by operating systems only, and can be enabled or disabled at any time by the operating system --------------------------------------------- INT 67 - LIM EMS 4.0 - PREPARE EXPANDED MEMORY HARDWARE FOR WARM BOOT AH = 5Ch Return: AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested --------------------------------------------- INT 67 - LIM EMS 4.0 - ENABLE/DISABLE OS FUNCTION SET FUNCTIONS AH = 5Dh AL = subfunction 00h enable OS Function Set 01h disable OS Function Set 02h return access key (resets memory manager, returns access key at next invocation) BX,CX = access key returned by first invocation Return: BX,CX = access key, returned only on first invocation of function AH = status 00h successful 80h internal error 81h hardware malfunction 84h undefined function requested 8Fh undefined subfunction A4h operating system denied access --------------------------------------------- INT 67 - EEMS - GET PHYSICAL WINDOW ARRAY AH = 60h ES:DI -> buffer Return: AH = status AL = number of entries buffer at ES:DI filled --------------------------------------------- INT 67 - EEMS - GENERIC ACCELERATOR CARD SUPPORT AH = 61h ??? Return: ??? Note: can be used by accelerator card manufacturer to flush RAM cache, ensuring that the cache accurately reflects what the processor would see without the cache. --------------------------------------------- INT 67 - EEMS - GET ADDRESSES OF ALL PAGE FRAMES IN SYSTEM AH = 68h ES:DI -> buffer Return: AH = status AL = number of entries buffer at ES:DI filled Note: equivalent to LIM 4.0 function 58h --------------------------------------------- INT 67 - EEMS - MAP PAGE INTO FRAME AH = 69h AL = frame number BX = page number DX = handle Return: AH = status Note: similar to EMS function 44h --------------------------------------------- INT 67 - EEMS - PAGE MAPPING AH = 6Ah AL = subfunction 00h save partial page map CH = first page frame CL = number of frames ES:DI -> buffer which is to be filled 01h restore partial page map CH = first page frame CL = number of frames DI:SI -> previously saved page map 02h save and restore partial page map CH = first page frame CL = number of frames ES:DI = buffer for current page map DI:SI = new page map 03h get size of save array CH = first page frame CL = number of frames Return: AL = size of array in bytes 04h switch to standard map register setting 05h switch to alternate map register setting 06h deallocate pages mapped to frames in conventional memory CH = first page frame CL = number of frames Return: AH = status Note: similar to EMS function 4Eh, except that a subrange of pages can be specified --------------------------------------------- --------------------------------------------- INT 80 - reserved for BASIC --------------------------------------------- INT 81 - reserved for BASIC --------------------------------------------- INT 82 - reserved for BASIC --------------------------------------------- INT 83 - reserved for BASIC --------------------------------------------- INT 84 - reserved for BASIC --------------------------------------------- INT 85 - reserved for BASIC --------------------------------------------- INT 86 - Relocated (by NETBIOS) INT 18 --------------------------------------------- INT 86 to F0 - used by BASIC while in interpreter --------------------------------------------- INT E0 - CP/M-86 function calls --------------------------------------------- INT EF - GEM - INTERFACE CX = 0473h DS:DX -> GEM parameter block --------------------------------------------- INT F0 - used by BASIC while in interpreter --------------------------------------------- INT F1 - reserved for user interrupt --------------------------------------------- INT F2 - reserved for user interrupt --------------------------------------------- INT F3 - reserved for user interrupt --------------------------------------------- INT F4 - reserved for user interrupt --------------------------------------------- INT F5 - reserved for user interrupt --------------------------------------------- INT F6 - reserved for user interrupt --------------------------------------------- INT F7 - reserved for user interrupt --------------------------------------------- INT F8 - 10 ms INTERVAL TIMER (TANDY???) --------------------------------------------- INT F9 - reserved for user interrupt --------------------------------------------- INT FA - USART READY (RS-232C) (TANDY???) --------------------------------------------- INT FB - USART Rx READY (keyboard) (TANDY???) --------------------------------------------- INT FC - reserved for user interrupt --------------------------------------------- INT FD - reserved for user interrupt --------------------------------------------- INT FE - AT/XT286/PS50+ - destroyed by return from protected mode --------------------------------------------- INT FF - AT/XT286/PS50+ - destroyed by return from protected mode --------------------------------------------- INT FF - Z100 - WARM BOOT ---------------------------------------------