Piper's Pit BBS/FTP: ibm 0010

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Text File | 1989-04-28 | 30.8 KB | 1,066 lines

.MODEL small, c INCLUDE demo.inc .CODE ;* DisableCGA - Disables CGA video by reprogramming the control register. ;* ;* Shows: Instructions - cli sti loopz loopnz ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: None ;* ;* Return: None DisableCGA PROC \ USES ax cx dx ; Preserve registers mov cx, -1 ; Set maximum loop count mov dx, 03DAh ; Address of status register wait1: in al, dx ; Get video status test al, 8 ; Vertical retrace active? loopnz wait1 ; Yes? Wait for end/timeout cli ; Disallow interruptions mov cx, -1 ; Reset loop count wait2: in al, dx ; Get video status test al, 8 ; Start of vertical retrace? loopz wait2 ; No? Wait for start/timeout sub dx, 2 ; DX = address of control reg mov al, 1 ; Value to disable CGA video out dx, al ; Disable video sti ; Reenable interrupts ret DisableCGA ENDP ;* EnableCGA - Enables CGA video by reprogramming the control register. ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: None ;* ;* Return: None EnableCGA PROC \ USES ax dx ; Preserve registers mov dx, 03D8h ; Address of control register mov al, vconfig.CGAvalue ; Reprogram with proper value out dx, al ; Enable video ret EnableCGA ENDP ;* WinOpen - Saves portion of screen to allocated memory, then opens a window ;* with specified fill attribute. See also the WinClose procedure. ;* ;* Shows: DOS Function - 48h (Allocate Memory Block) ;* BIOS Interrupt - 10h, Function 6 (Initialize or Scroll Up Window) ;* Instructions - movsw stosw rep ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: row1 - Row at top of window ;* col1 - Column at left edge of window ;* row2 - Row at bottom of window ;* col2 - Column at right edge of window ;* attr - Fill attribute for window ;* ;* Return: Short integer with segment address of allocated buffer, or ;* 0 if unable to allocate memory WinOpen PROC \ USES ds di si, \ row1:WORD, col1:WORD, row2:WORD, col2:WORD, attr:WORD GetVidOffset row1, col1 ; Get offset in video segment mov si, ax ; SI = video offset for window mov bx, row2 sub bx, row1 inc bx ; BX = number of window rows mov cx, col2 sub cx, col1 inc cx ; CX = number of columns mov ax, cx ; Compute number of video mul bl ; cells in window add ax, 3 ; Plus 3 additional entries shr ax, 1 ; Shift right 3 times to shr ax, 1 ; multiply by 2 bytes/cell, shr ax, 1 ; divide by 16 bytes/para inc ax ; Add a paragraph push bx ; Save number of rows mov bx, ax ; BX = number of paragraphs mov ah, 48h ; Request DOS Function 48h int 21h ; Allocate Memory Block pop bx jnc @F ; If successful, continue sub ax, ax ; Else return null pointer jmp SHORT exit @@: mov es, ax ; Point ES:DI to allocated sub di, di ; buffer mov ax, si stosw ; Copy video offset to buffer mov ax, bx stosw ; Number of rows to buffer mov ax, cx stosw ; Number of cols to buffer mov ax, 160 ; Number of video cells/row mov ds, vconfig.sgmnt ; DS = video segment loop1: push si ; Save ptr to start of line push cx ; and number of columns cmp vconfig.adapter, CGA ; CGA adapter? jne @F ; No? Skip video disable ; For CGA adapters, WinOpen avoids screen "snow" by disabling the video prior ; to block memory moves, then reenabling it. Although this technique can ; result in brief flickering, it demonstrates the fastest way to access a ; block in the CGA video buffer without causing display snow. See also the ; StrWrite procedure for another solution to the problem of CGA snow. call DisableCGA ; Yes? Disable video @@: rep movsw ; Copy one row to buffer cmp vconfig.adapter, CGA jne @F call EnableCGA ; Reenable CGA video @@: pop cx ; Recover number of columns pop si ; and start of line add si, ax ; Point to start of next line dec bx ; Decrement row counter jnz loop1 ; Loop while rows remain ; Screen contents (including display attributes) are now copied to buffer. ; Next open window, overwriting the screen portion just saved. mov ax, 0600h ; Scroll service mov bh, BYTE PTR attr ; Fill attribute mov cx, col1 ; CX = row/col for upper left mov ch, BYTE PTR row1 mov dx, col2 ; DX = row/col for lower right mov dh, BYTE PTR row2 int 10h ; Blank window area on screen mov ax, es ; Return address of allocated exit: ret ; segment WinOpen ENDP ;* WinClose - "Closes" a window previously opened by the WinOpen procedure. ;* See also the WinOpen procedure. ;* ;* Shows: DOS Function - 49h (Release Memory Block) ;* Instructions - lodsw ;* Operators - : (segment override) SEG ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: addr - Segment address of buffer that holds screen contents ;* saved in WinOpen procedure ;* ;* Return: None WinClose PROC \ USES ds di si, \ addr:WORD mov ds, addr ; DS:SI points to buffer sub si, si lodsw mov di, ax ; DI = video offset of window lodsw mov bx, ax ; BX = number of window rows lodsw mov cx, ax ; CX = number of columns mov ax, SEG vconfig.sgmnt mov es, ax ; Point ES to data segment push es:vconfig.sgmnt pop es ; ES = video segment mov ax, 160 ; Number of video cells/row loop1: push di ; Save ptr to start of line push cx ; and number of columns cmp vconfig.adapter, CGA ; CGA adapter? jne @F ; No? Skip video disable ; Disable CGA video prior to memory move to avoid screen snow. (See the ; WinOpen and StrWrite procedures for further discussions on CGA snow.) call DisableCGA ; Yes? Disable video @@: rep movsw ; Copy one row to buffer cmp vconfig.adapter, CGA jne @F call EnableCGA ; Reenable CGA video @@: pop cx ; Recover number of columns pop di ; and start of line add di, ax ; Point to start of next line dec bx ; Decrement row counter jnz loop1 ; Loop while rows remain mov ah, 49h ; Request DOS Function 49h mov es, addr int 21h ; Release Memory Block ret WinClose ENDP ;* SetCurSize - Sets cursor size. ;* ;* Shows: BIOS Interrupt - 10h, Function 1 (Set Cursor Type) ;* ;* Params: scan1 - Starting scan line ;* scan2 - Ending scan line ;* ;* Return: None SetCurSize PROC \ scan1:WORD, scan2:WORD mov cx, scan2 ; CL = ending scan line mov ch, BYTE PTR scan1 ; CH = starting scan line mov ah, 1 ; Function 1 int 10h ; Set Cursor Type ret SetCurSize ENDP ;* GetCurSize - Gets current cursor size. ;* ;* Shows: BIOS Interrupt - 10h, Function 3 (Get Cursor Position) ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: None ;* ;* Return: Short integer with high byte = top scan line, ;* low byte = bottom scan line GetCurSize PROC mov ah, 3 ; Function 3 mov bh, vconfig.dpage int 10h ; Get Cursor Position mov ax, cx ; Return cursor size ret GetCurSize ENDP ;* GetCurPos - Gets current cursor position. ;* ;* Shows: BIOS Interrupt - 10h, Function 3 (Get Cursor Position) ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: None ;* ;* Return: Short integer with high byte = row, low byte = column GetCurPos PROC mov ah, 3 ; Function 3 mov bh, vconfig.dpage int 10h ; Get cursor position mov ax, dx ; Return cursor row/column ret GetCurPos ENDP ;* GetShift - Gets current shift status. Checks for extended keyboard, ;* and if available returns additional shift information. ;* ;* Shows: BIOS Interrupt - 16h, Functions 2 and 12h (Get Keyboard Flags) ;* ;* Params: None ;* ;* Return: Long integer ;* high word = 0 for non-extended keyboard ;* 1 for extended keyboard ;* low word has following bits set when indicated keys are pressed: ;* 0 - Right shift 8 - Left Ctrl ;* 1 - Left shift 9 - Left Alt ;* 2 - Ctrl 10 - Right Ctrl ;* 3 - Alt 11 - Right Alt ;* 4 - Scroll Lock active 12 - Scroll Lock pressed ;* 5 - Num Lock active 13 - Num Lock pressed ;* 6 - Caps Lock active 14 - Caps Lock pressed ;* 7 - Insert toggled 15 - Sys Req pressed GetShift PROC sub dx, dx ; Assume non-extended keyboard mov ah, 2 ; and use Function 2 mov es, dx ; Point ES to low memory test BYTE PTR es:[496h], 16 ; Extended keyboard installed? jz @F ; No? Leave AH as Function 2 inc dx ; Yes? Set high word of return code mov ah, 12h ; and use Function 12h @@: int 16h ; Get Keyboard Flags ret GetShift ENDP ;* GetKeyClock - Waits for keypress while updating time at specified location ;* on screen. ;* ;* Shows: BIOS Interrupt - 16h, Functions 0 and 10h (Read Character) ;* 16h, Functions 1 and 11h (Get Keyboard Status) ;* DOS Functions - 2Ah (Get Date) ;* 2Ch (Get Time) ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: row - Screen row for clock display ;* col - Screen column for clock display ;* ;* Return: Short integer with key scan code in high byte and ASCII ;* character code in low byte. Low byte is 0 for special ;* keys (such as the "F" keys) which don't generate characters. .DATA PUBLIC datestr datestr DB ' - - : : ', 0 ; Date/time string .CODE EXTRN StrWrite:PROC GetKeyClock PROC \ row:WORD, col:WORD LOCAL service:BYTE call GetShift ; Check for extended keyboard mov service, 11h ; Request for Function 11h cmp dx, 1 ; Extended keyboard available? je key1 ; Yes? Set AH appropriately mov service, 1 ; No? Set AH for Function 1 key1: mov ah, service int 16h ; Get Keyboard Status jnz exit ; Ready? Exit procedure ; Not ready? Check text mode cmp vconfig.mode, 7 ; Monochrome text mode? je @F ; Yes? Continue cmp vconfig.mode, 3 ; Color text mode? je @F ; Yes? Continue cmp vconfig.mode, 2 ; Black/white? jne key1 ; No? Skip clock update and ; poll keyboard again ; If 80-column text, get date and time from DOS before again polling keyboard, ; and display at upper right corner of screen. @@: mov ah, 2Ch ; Request time int 21h ; Get Time mov dl, dh push dx ; Save seconds, push cx ; minutes, mov cl, ch ; and push cx ; hours mov ah, 2Ah ; Request date int 21h ; Get Date sub cx, 1900 ; Subtract century, CL = year push cx ; Save year, push dx ; day, mov dl, dh ; and push dx ; month mov cx, 6 sub bx, bx loop1: pop ax ; Recover all 6 numbers in AL aam ; Convert to unpacked BCD xchg al, ah ; Switch bytes for word move or ax, '00' ; Make ASCII numerals mov WORD PTR datestr[bx], ax; Copy to string add bx, 3 ; at every third byte loop loop1 DispText row, col, <OFFSET datestr> jmp key1 ; Loop again for keypress exit: mov ah, service ; 1 or 11h, depending on keybd dec ah ; Set AH to 0 or 10h int 16h ; Get key to remove it from ret ; keyboard buffer GetKeyClock ENDP ;* GetPSP - Gets address of Program Segment Prefix. For DOS 3.0 or higher. ;* ;* Shows: DOS Function - 62h (Get PSP Address) ;* Instruction - call (See the MISCDEMO.ASM example program ;* for an example of a call dispatch table) ;* ;* Params: None ;* ;* Return: Short integer with PSP segment address ;* or 0 if DOS version below 3.0 EXTRN GetVer:PROC GetPSP PROC call GetVer ; Get DOS version number cmp ax, 300 ; Version 3.0 or higher? jb dos2 ; No? Return error code mov ah, 62h ; Yes? Query DOS for PSP int 21h ; Get PSP Address mov ax, bx ; Put in AX jmp SHORT exit ; Exit dos2: sub ax, ax ; For version 2, return 0 exit: ret GetPSP ENDP ;* GetMem - Gets total size of memory and determines the largest amount of ;* unallocated memory available. GetMem invokes DOS Function 48h (Allocate ;* Memory) to request an impossibly large memory block. DOS denies the re- ;* quest, but returns instead the size of the largest block available. This ;* is the amount that GetMem returns to the calling program. See the WinOpen ;* procedure for an example of calling Function 48h to allocate unused memory. ;* ;* Shows: BIOS Interrupt - 12h (Get Conventional Memory Size) ;* ;* Params: None ;* ;* Return: Long integer, high word = total memory in kilobytes (KB) ;* low word = largest block of available memory (KB) GetMem PROC int 12h ; Get total memory in K push ax ; Save size of memory mov ah, 48h ; Request memory allocation mov bx, 0FFFFh ; Ensure request is denied for ; impossibly large block int 21h ; Get largest available block in BX mov ax, bx ; Copy to AX mov cl, 6 ; Convert paragraphs to kilobytes by shr ax, cl ; dividing by 64 pop dx ; Recover total in DX ret ; Return long integer DX:AX GetMem ENDP ;* VeriPrint - Checks if LPT1 (PRN) is available. ;* ;* Shows: BIOS Interrupt - 17h (Parallel Port Printer Driver) ;* ;* Params: None ;* ;* Return: Short integer, 1 for yes or 0 for no VeriPrint PROC mov ah, 2 ; Check printer status for sub dx, dx ; parallel printer (port 0) int 17h xchg dx, ax ; Put 0 (for error) in AX test dh, 00101001b ; Are any error bits on? jne exit ; Yes? Leave 0 test dh, 10010000b ; Are both operation bits on? jz exit ; No? Leave 0 inc ax ; Yes? Return 1 exit: ret VeriPrint ENDP ;* IntToAsc - Converts integer to ASCII string. This procedure is useful ;* only for assembly language, and is not intended to be C-callable. ;* ;* Shows: Instructions - cwd aam xchg ;* ;* Entry: AX = integer (9999 max) ;* ;* Return: DX:AX = 4-digit ASCII number IntToAsc PROC cwd ; Zero DX register mov cx, 100 ; Divide AX by 100, yields div cx ; AX=quotient, DX=remainder aam ; Make digits unpacked BCD or ax, '00' ; Convert to ASCII xchg ax, dx ; Do same thing for DX aam or ax, '00' ret ; Return DX:AX = ASCII number IntToAsc ENDP ;* VeriAnsi - Checks for ANSI driver by writing ANSI sequence to report ;* cursor position. If report compares with position returned from ;* GetCurPos procedure, then ANSI driver is operating. ;* ;* Shows: DOS Functions - 06h (Direct Console I/O) ;* 0Ch (Flush Input Buffer and then Input) ;* ;* Params: None ;* ;* Return: Short integer, 1 for yes or 0 for no .DATA PUBLIC report report DB ESCAPE, '[6n$' ; ANSI Report Cursor sequence .CODE VeriAnsi PROC call GetCurPos ; Cursor position from BIOS mov cx, ax ; Save it in CX mov dx, OFFSET report ; ANSI string to get position mov ah, 9 ; Request DOS String Output int 21h ; Write ANSI escape sequence mov ah, 6 ; Skip Esc character in mov dl, 0FFh ; keyboard buffer int 21h jz e_exit ; If no key, ANSI not loaded mov ah, 6 ; Skip '[' character int 21h jz e_exit ; If no key, ANSI not loaded mov ah, 6 ; Get 1st digit of cursor row int 21h jz e_exit ; If no key, ANSI not loaded mov bh, al ; Store in BH mov ah, 6 ; Get 2nd digit of cursor row int 21h jz e_exit ; If no key, ANSI not loaded mov bl, al ; Store in BL mov al, ch ; Get original row # in AL cbw ; AX = row # from GetCurPos inc ax ; Add 1 to it call IntToAsc ; Make ASCII digits cmp ax, bx ; ANSI and BIOS reports match? jne e_exit ; No? Then ANSI not loaded mov ax, 0C06h ; Flush remaining ANSI keys mov dl, 0FFh ; from buffer int 21h mov ax, 1 ; Set 1 for true jmp SHORT exit ; and exit e_exit: sub ax, ax ; Set 0 return code if no exit: ret ; ANSI driver installed VeriAnsi ENDP ;* VeriCop - Checks for coprocessor. ;* ;* Shows: BIOS Interrupt - 11h (Get Equipment Configuration) ;* ;* Params: None ;* ;* Return: Short integer, 1 for yes or 0 for no VeriCop PROC int 11h ; Check peripherals test al, 2 ; Coprocessor? mov ax, 0 ; Assume no, don't alter flags jz exit ; No? Done inc ax ; Yes? Set to 1 exit: ret VeriCop ENDP ;* SetLineMode - Sets line mode for EGA or VGA. ;* ;* Shows: BIOS Interrupt - 10h, Function 11h (Character Generator Interface) ;* 10h, Function 12h (Video Subsystem Configuration) ;* Instruction - cmp ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: line - Requested line mode (25, 43, or 50) ;* ;* Return: Short integer with error code ;* 0 if successful ;* 1 if error SetLineMode PROC \ line:WORD cmp vconfig.adapter, EGA ; EGA or VGA? jge @F ; Yes? Continue jmp e_exit ; No? Exit with error @@: mov ax, line ; Check for valid parameter cmp al, 25 je line25 cmp al, 43 je line43 cmp al, 50 je line50 jmp SHORT e_exit ; If not 25, 43, or 50, exit w/ error line25: mov al, 11h ; Set for EGA 25-line mode cmp vconfig.adapter, EGA ; EGA? je lmode ; Yes? Continue mov ax, 1202h ; No? Function 12h for VGA mov bl, 30h ; AL = 2 for 400 scan lines int 10h ; Reset to 400 scan lines mov ax, 0003 ; Reset mode (Function 0) int 10h ; to mode 3 (80-col text) mov al, 14h ; Request 8x16 char matrix jmp SHORT lmode line43: mov al, 12h ; Set for EGA 43-line mode cmp vconfig.adapter, EGA ; EGA? je lmode ; Yes? Continue mov ax, 1201h ; No? Function 12h for VGA mov bl, 30h ; AL = 1 for 350 scan lines int 10h ; Reset to 350 scan lines mov ax, 0003 ; Reset mode (Function 0) int 10h ; to mode 3 (80-col text) mov al, 12h ; Request 8x8 character matrix jmp SHORT lmode line50: cmp vconfig.adapter, VGA ; VGA? jne e_exit ; No? Exit with error mov ax, 1202h ; Yes? Function 12h mov bl, 30h ; AL = 2 for 400 scan lines int 10h ; Reset to 400 scan lines mov ax, 0003 ; Reset mode (Function 0) int 10h ; to mode 3 (80-col text) mov al, 12h ; Request 8x8 character matrix lmode: sub bl, bl ; Use table 0 mov ah, 11h ; Request Function 11h int 10h ; Set new line mode mov ah, 12h ; Select alternate print mov bl, 20h ; screen for EGA and VGA int 10h cmp vconfig.adapter, VGA ; VGA? je exit ; Yes? Then exit cmp line, 12h ; If EGA 43-line mode, set je port ; cursor through port to ; avoid cursor emulation bug mov al, 7 ; Else use BIOS to set cursor push ax ; Pass bottom scan line mov al, 6 push ax ; Pass top scan line call SetCurSize ; Set normal cursor add sp, 4 ; Clean stack jmp SHORT exit ; Exit port: mov dx, 03D4h ; Video controller address mov ax, 060Ah ; Set AH = 06h (cursor start) ; AL = 0Ah (register #) out dx, ax ; Update port mov ax, 000Bh ; Set AH = 00h (cursor end) ; AL = 0Bh (register #) out dx, ax ; Update port jmp SHORT exit ; Normal exit e_exit: mov ax, 1 ; Set error code jmp SHORT @F exit: sub ax, ax ; Clear error code @@: ret SetLineMode ENDP ;* Pause - Waits for specified number of clocks to elapse, then returns. ;* ;* Shows: BIOS Interrupt - 1Ah, Function 0 (Real-Time Clock Driver) ;* Operators - LOCAL [] ;* ;* Params: duration - Desired duration in clocks, where ;* 18 clocks = approx 1 second ;* ;* Return: None Pause PROC \ duration:WORD LOCAL time:DWORD sub ah, ah int 1Ah ; Get Clock Count in CX:DX add dx, duration ; Add pause time to it adc cx, 0 mov WORD PTR time[0], dx ; Result is target time; mov WORD PTR time[2], cx ; keep in local variable loop1: int 1AH ; Now repeatedly poll clock cmp dx, WORD PTR time[0] ; count until the target jb loop1 ; time is reached cmp cx, WORD PTR time[2] jb loop1 ret Pause ENDP ;* Sound - Sounds speaker with specified frequency and duration. ;* ;* Shows: Instructions - in out ;* ;* Params: freq - Desired frequency of sound in Hertz ;* duration - Desired duration in clocks, where ;* 18 clocks = approx 1 second ;* ;* Return: None Sound PROC \ freq:WORD, duration:WORD mov al, 0B6h ; Initialize channel 2 of out 43h, al ; timer chip mov dx, 12h ; Divide 1,193,182 Hertz mov ax, 34DEh ; (clock frequency) by div freq ; desired frequency ; Result is timer clock count out 42h, al ; Low byte of count to timer mov al, ah out 42h, al ; High byte of count to timer in al, 61h ; Read value from port 61h or al, 3 ; Set first two bits out 61h, al ; Turn speaker on push duration call Pause ; Pause for specified time add sp, 2 ; Clean stack on return in al, 61h ; Get port value xor al, 3 ; Kill bits 0-1 to turn out 61h, al ; speaker off ret Sound ENDP ;* WriteTTY - Displays ASCIIZ string at cursor position, in either text ;* or graphics mode. ;* ;* Shows: BIOS Interrupt - 10h, Function 0Eh (Write Character in TTY Mode) ;* Instruction - loop ;* ;* Uses: vconfig - Video configuration structure, declared in the ;* DEMO.INC include file. The structure must first be ;* initialized by calling the GetVidConfig procedure. ;* ;* Params: str - Pointer to ASCIIZ string ;* icolor - Color index (for graphics mode only) ;* ;* Return: None WriteTTY PROC \ USES ds si, \ str:PTR BYTE, icolor:WORD mov bx, icolor ; BL = color index mov bh, vconfig.dpage ; BH = current display page LoadPtr ds, si, str mov cx, -1 ; Set loop counter to maximum mov ah, 14 ; Function 14 loop1: lodsb ; Get character from string or al, al ; NULL string terminator? jz exit ; Yes? Exit int 10h ; No? Display, advance cursor loop loop1 ; Loop to get next character exit: ret WriteTTY ENDP ;* Colors - Alters screen colors within a specified area by using bit ;* or move operations on display attribute bytes in video memory. ;* ;* Shows: Instructions - not rol ror and xor or ;* ;* Params: logic - Code number, 0 = NOT 2 = ROR 4 = XOR 6 = MOV ;* 1 = ROL 3 = AND 5 = OR ;* attr - Attribute mask ;* row1 - Row at top of window ;* col1 - Column at left edge of window ;* row2 - Row at bottom of window ;* col2 - Column at right edge of window ;* ;* Return: None Colors PROC \ USES ds si, \ logic:WORD, attr:WORD, row1:WORD, col1:WORD, row2:WORD, col2:WORD GetVidOffset row1, col1 ; Get offset in video segment inc ax mov si, ax ; SI = offset for 1st attr byte mov bx, row2 sub bx, row1 inc bx ; BX = number of window rows mov cx, col2 sub cx, col1 inc cx ; CX = number of columns mov ds, vconfig.sgmnt ; DS = video segment mov ax, attr ; AL = mask for and, xor, and or loop1: push si ; Save ptr to start of line push cx ; and number of columns cmp vconfig.adapter, CGA ; CGA adapter? jne @F ; No? Skip video disable ; Disable CGA video prior to memory access to avoid screen snow. (See the ; WinOpen and StrWrite procedures for further discussions on CGA snow.) call DisableCGA ; Yes? Disable video @@: cmp logic, 1 ; Rotate left? jl c_not ; If less, do NOT je c_rol ; If equal, do ROL cmp logic, 3 ; And? jl c_ror ; If less, do ROR je c_and ; If equal, do AND cmp logic, 5 ; Or? jl c_xor ; If less, do XOR je c_or ; If equal, do OR ; Otherwise, do MOV c_mov: mov BYTE PTR [si], al ; MOV attr parameter add si, 2 ; into attribute byte loop c_mov jmp SHORT c_done c_or: or BYTE PTR [si], al ; OR with attr parameter add si, 2 loop c_or jmp SHORT c_done c_xor: xor BYTE PTR [si], al ; XOR with attr parameter add si, 2 loop c_xor jmp SHORT c_done c_and: and BYTE PTR [si], al ; AND with attr parameter add si, 2 loop c_and jmp SHORT c_done c_ror: ror BYTE PTR [si], 1 ; Rotate right 1 bit add si, 2 loop c_ror jmp SHORT c_done c_rol: rol BYTE PTR [si], 1 ; Rotate left 1 bit add si, 2 loop c_rol jmp SHORT c_done c_not: not BYTE PTR [si] ; Flip bits add si, 2 loop c_not c_done: cmp vconfig.adapter, CGA jne @F call EnableCGA ; Reenable CGA video @@: pop cx ; Recover number of columns pop si ; Recover offset for start of line add si, 160 ; Point to start of next line dec bx ; Decrement row counter jnz loop1 ; Loop while rows remain ret ; Exit when all lines complete Colors ENDP ;* Exec - Executes a child process. Exec handles the usual chores associated ;* with spawning a process: (1) parsing the command line tail and loading the ;* FCBs with the first two arguments; (2) setting and restoring the vectors ;* for Interrupts 1Bh, 23h, and 24h; and (3) querying DOS for the child's ;* return code. ;* ;* Shows: DOS Functions - 29h (Parse Filename) ;* 25h (Set Interrupt Vector) ;* 35h (Get Interrupt Vector) ;* 4Bh (Execute Program) ;* 4Dh (Get Return Code) ;* ;* Params: spec - Pointer to ASCIIZ specification for program file ;* (must include .COM or .EXE extension) ;* block - Pointer to parameter block structure ;* break - Pointer to new Ctrl-Break (Interrupt 1Bh) handler ;* ctrlc - Pointer to new Ctrl-C (Interrupt 23h) handler ;* criterr - Pointer to new Critical Error (Interrupt 24h) handler ;* ;* Return: Short integer with child return code, or -1 for EXEC error Exec PROC \ USES ds si di, \ spec:PTR BYTE, block:PTR parmblk, break:PTR BYTE, \ ctrlc:PTR BYTE, criterr:PTR BYTE jmp SHORT @F ; Jump over data area old_1Bh DD WORD PTR ? ; Keep vectors for Interrupts old_23h DD WORD PTR ? ; 1Bh, 23h, and 24h in old_24h DD WORD PTR ? ; code segment old_stk DD WORD PTR ? ; Keep stack pointer @@: Vector 1Bh, cs:old_1Bh, break ; Save, replace Int 1Bh vector Vector 23h, cs:old_23h, ctrlc ; Save, replace Int 23h vector Vector 24h, cs:old_24h, criterr ; Save, replace Int 24h vector LoadPtr ds, bx, block ; Point DS:BX to parameter block push ds ; Save segment address les di, [bx].fcb1 ; Point ES:DI to first FCB lds si, [bx].taddr ; Point DS:SI to command line tail inc si ; Skip over count byte mov ax, 2901h ; Set AH to request Function 29h ; AL = flag to skip leading blanks int 21h ; Parse command-line into first FCB pop es ; Recover seg addr of parameter block les di, es:[bx].fcb2 ; Point ES:DI to second FCB mov ax, 2901h ; Request DOS Function #29h again int 21h ; Parse command-line into second FCB push bp ; Save only important register mov WORD PTR cs:old_stk[0], sp mov WORD PTR cs:old_stk[2], ss LoadPtr es, bx, block ; ES:BX points to param block LoadPtr ds, dx, spec ; DS:DX points to path spec mov ax, 4B00h ; AH = DOS Function 4Bh ; AL = 0 for load and execute int 21h ; Execute Program mov sp, WORD PTR cs:old_stk[0] ; Reset stack pointers mov ss, WORD PTR cs:old_stk[2] pop bp ; Recover saved register ; Restore vectors for Interrupts 1Bh, 23h, and 24h. mov ax, 251Bh ; AH = DOS Function 25h ; AL = interrupt number lds dx, cs:old_1Bh ; DS:DX = original vector int 21h ; Set Interrupt 1Bh Vector mov al, 23h ; AL = interrupt number lds dx, cs:old_23h ; DS:DX = original vector int 21h ; Set Interrupt 23h Vector mov al, 24h ; AL = interrupt number lds dx, cs:old_24h ; DS:DX = original vector int 21h ; Set Interrupt 24h Vector mov ax, -1 ; Set error code jc exit ; If EXEC error, exit mov ah, 4Dh ; Else request child's code int 21h ; Get Return Code sub ah, ah ; Make short integer exit: ret Exec ENDP ;* BinToHex - Converts binary word to 6-byte hexadecimal number in ;* ASCIIZ string. String is right-justified and includes "h" radix. ;* ;* Shows: Instruction - xlat ;* ;* Params: num - Number to convert to hex string ;* str - Pointer to 6-byte string ;* ;* Return: None .DATA hex DB '0123456789ABCDEF' ; String of hex numbers .CODE BinToHex PROC \ USES di, \ num:WORD, str:PTR BYTE LoadPtr es, di, str ; Point ES:DI to 6-byte string mov bx, OFFSET hex ; Point DS:BX to hex numbers mov ax, num ; Number in AX mov cx, 2 ; Loop twice for two bytes loop1: xchg ah, al ; Switch bytes push ax ; Save number shr al, 1 ; Shift high nibble to low shr al, 1 shr al, 1 shr al, 1 xlat ; Get equivalent ASCII number in AL stosb ; Copy to 6-byte string, increment DI pop ax ; Recover number push ax ; Save it again and al, 00001111b ; Mask out high nibble xlat ; Get equivalent ASCII number in AL stosb ; Copy to 6-byte string, increment DI pop ax ; Recover number loop loop1 ; Do next byte mov ax, 'h' ; Put null, 'h' radix in AX stosw ; Copy to last two bytes in string ret BinToHex ENDP ;* NewBlockSize - Adjusts size of allocated memory block. ;* ;* Shows: DOS Function - 4Ah (Resize Memory Block) ;* ;* Params: addr - Segment address of block ;* resize - Requested block size in paragraphs ;* ;* Return: Short integer error code ;* 0 if successful ;* 1 if error NewBlockSize PROC \ addr:WORD, resize:WORD mov ax, addr ; Get block address mov es, ax ; Point ES to block mov bx, resize ; New block size mov ah, 4Ah ; Function number int 21h ; Resize Memory Block ret NewBlockSize ENDP ;* Initialize - Initializes global variables _psp and _env, which are defined ;* in the DEMO.INC include file. If used with a DOS version less than 3.0, ;* this procedure will not produce valid results unless it is called before ;* changing the ES register. This is because at program entry ES points to ;* the Program Segment Prefix (PSP). ;* ;* Params: None ;* ;* Return: None Initialize PROC call GetPSP ; Get segment address of PSP or ax, ax ; DOS version less than 3.0? jz @F ; Yes? Assume ES points to PSP mov es, ax ; No? Reload ES with PSP address @@: mov _psp, es ; Initialize variable with PSP address mov ax, es:[2Ch] ; Get environment seg from PSP mov _env, ax ; Store it ret Initialize ENDP END