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Assembly Source File | 1994-12-31 | 70.6 KB | 1,843 lines

;------------------------------------------------------------------------------- ; MODE -- Mode setting utility for Free-DOS ; ; Written for the Free-DOS project. ; (c) Copyright 1994-1995 by K. Heidenstrom. ; ; This program is free software. You may redistribute the source and ; executable in unmodified form and/or modify it for your own use only. ; If you make any changes, please include a note to that effect in the ; usage summary. Do not distribute modified versions of this program. ; If you make significant improvements, please consider sending the ; change details to the author, kheidens@actrix.gen.nz on the Internet ; or K. Heidenstrom c/- P.O. Box 27-103, Wellington, New Zealand, so ; that other Free-DOS users may benefit. ; ; This program is provided "as-is" without any warranty of any kind, ; including the implied warranty of merchantability or fitness for a ; particular purpose. In no event will the author be liable for any ; damages of any kind related to the use of this program. ; ; This program is based on, but not derived from, the DR-DOS MODE program. ; In writing this program, I used only the functionality and usage syntax ; of that program as a guideline. I have no knowledge of the internal ; operation of the original MODE program and I did not disassemble it to ; determine how it works, nor did I use any code from it. In other words, ; this program is an entirely original work, based only on the documented ; functionality and command syntax of the original MODE program. KH.941230. ; ; See the accompanying file MODE.TXT for more information. ; ;------------------------------------------------------------------------------- ; ; This program must be assembled with Borland's TASM. The syntax is: ; ; tasm /ml /t /w2 mode; ; tlink /t mode, mode, nul ; ;------------------------------------------------------------------------------- ; ; Modified: ; ; KH.941123.001 0.0.0 Started ; KH.941124.002 Design ; KH.941212.003 Design ; KH.941227.004 Parameter handlers working ; KH.941228.005 Typematic and COM functions working ; KH.941229.006 PARK functions implemented - still need LPT and video ; KH.941230.007 LPT infinite retries and redirection implemented ; KH.941231.008 1.0.0 First version, probably lots of bugs lurking here Ver EQU 1 SubVer EQU 0 ModVer EQU 0 VerDate EQU "941231" ; YYMMDD format ;------------------------------------------------------------------------------- PAGE ,132 IDEAL %TITLE "MODE -- Mode setting utility for Free-DOS" NAME MODE ; Equates AppName EQU "MODE" ; Shorthand MACRO point Reg,Label mov Reg,OFFSET Label ENDM MACRO DBBW Byte1,Byte2,Word DB Byte1,Byte2 DW Word ENDM MACRO prexp Text1,Exp,Text2 ; Invoke in MASM mode only %OUT Text1 &Exp Text2 ENDM NL EQU 13,10 ; Program SEGMENT ComFile ASSUME cs:ComFile,ds:ComFile,es:nothing,ss:nothing ORG 0100h ; Com-type file PROC Main near jmp Main2 ENDP Main Signature DB "SIG: Free-DOS MODE.COM version ",Ver+"0",".",SubVer+"0",".",ModVer+"0",", ",VerDate,": " ;--------------- ;!! Change the following line if you create a derivative version of this program DB "Original" ;--------------- DB " ",26 ; Ctrl-Z SigLen = $ - Main ; Length of program signature ; Resident data ================================================================ Int8Busy DB 0 ; Flag whether int 8 is parking now Int13Busy DB 0 ; Flag whether disk request in progress Park_Ticks DW 0 ; Number of ticks or zero for Mode_Park ParkDrive0 DW 0 ; Control variable for parking drive 0 ParkDrive1 DW 0 ; Control variable for parking drive 1 ; Printer persistent behaviour and serial port redirection control bytes: ; ; 7 6 5 4 3 2 1 0 ; * . . . . . . . Persistent mode: 0=Normal, 1=Persistent ; . * * * * . . . Not used ; . . . . . * * * Redirection: 0=None, 1-4 = COM1-COM4, 7=NUL LPT_Ctrl DB 0,0,0,0 ; Printer persistent/redirection control ; Resident code ================================================================ ASSUME ds:nothing ; Int 8 intercepter ------------------------------------------------------------ ; The int 8 intercepter hooks into the hardware timer tick interrupt and is ; used by the timeout park function. When a hard drive is accessed via int ; 13h, the ParkDrive0 or ParkDrive1 variable is reset to the timeout period ; (Park_Ticks). These two counter variables are handled separately. Each is ; decremented (if non-zero) on every tick by the int 8 handler. When the ; counter variable decrements to zero, the appropriate drive is parked. This ; is done by the int 8 handler. ; When the int 8 handler decides to park a drive, it chains to the original ; handler first. This causes an EOI to be issued, thus lower priority ; interrupts and other timer tick interrupts are enabled. During the time ; that the hard drive is being parked, the Int8Busy flag is set. If the ; int 8 intercepter is entered with this flag set, it will just chain to the ; original handler without performing its normal timeout function. ; If the ParkDrive0 or ParkDrive1 variables are zero, this indicates that they ; have timed out and the park has been performed; they will not be decremented. ; I know that on the tick when drive 0 is parked, the drive 1 tick count will ; not be decremented - I don't care; the timing error is insignificant. ASSUME ds:nothing PROC New08 far ; Int 08h (timer tick) intercepter pushf ; Preserve flags cmp [Int8Busy],0 ; Check whether we're already busy jnz GoOld08 ; If so, don't do anything cmp [ParkDrive0],0 ; Drive 0 already timed out? jnz DecrDrive0 ; If not CheckDrive1: cmp [ParkDrive1],0 ; Drive 1 already timed out? jnz DecrDrive1 ; If not ; Idle - just jump to old handler GoOld08: popf ; Fix stack DB 0EAh ; JMP xxxx:yyyy Old08Vec = THIS DWORD ; Vector to original handler Old08Ofs DW 0 ; Offset Old08Seg DW 0 ; Segment DecrDrive0: dec [ParkDrive0] ; Count down ticks for drive 0 park jnz CheckDrive1 ; If not zero yet ; Time to park drive 0 - make sure no disk operation is in progress first! cmp [Int13Busy],0 ; Check for disk operation in progress jz DoPark0 ; If idle inc [ParkDrive0] ; Try again next tick jmp SHORT CheckDrive1 ; Handle the drive 1 counter and exit ; Safe to park drive 0 - do it DoPark0: inc [Int8Busy] ; Set busy flag pushf ; Simulate stack for an INT call [Old08Vec] ; Chain to original handler (send EOI) sti ; Enable interrupts push dx ; Preserve push cx ; Preserve push ax ; Preserve mov dx,80h ; Drive I.D is 80h for first hard disk DB 0B9h ; MOV CX,nnnn MaxCylinder0 DW 0 ; Operand is modified by install code jmp SHORT DoSeek ; Go to common do-seek and return stuff ; Count down timer for drive 1 DecrDrive1: dec [ParkDrive1] ; Count down ticks for drive 1 park jnz GoOld08 ; If not zero yet ; Time to park drive 1 - make sure no disk operation is in progress first! cmp [Int13Busy],0 ; Check for disk operation in progress jz DoPark1 ; If idle inc [ParkDrive1] ; Try again next tick jmp SHORT GoOld08 ; Nothing more we can do at the moment ; Safe to park drive 1 - do it DoPark1: inc [Int8Busy] ; Set busy flag pushf ; Simulate stack for an INT call [Old08Vec] ; Chain to original handler (send EOI) sti ; Enable interrupts push dx ; Preserve push cx ; Preserve push ax ; Preserve mov dx,81h ; Drive I.D is 81h for second hard disk DB 0B9h ; MOV CX,nnnn MaxCylinder1 DW 0 ; Operand is modified by install code DoSeek: jcxz NoSuchDrive ; If no such drive mov ah,0Ch ; Seek function pushf ; Simulate INT call [cs:Old13Vec] ; Don't issue int 13h - that would reset NoSuchDrive: pop ax ; the timeout counter! pop cx ; Restore pop dx ; Restore mov [Int8Busy],0 ; No longer busy popf ; Restore flags pushed at start of int 8 iret ; Finally, return to application ENDP New08 ; Int 13h intercepter ---------------------------------------------------------- ; The int 13h intercepter hooks into the disk function interrupt and is ; responsible for resetting the park timeout counters used by the int 8 ; intercepter when the hard drive(s) is/are accessed. The first two ; physical hard drives are supported. It also maintains the Int13Busy ; flag which is used by the int 8 intercepter to ensure that it does not ; call int 13h while another floppy or hard disk request is in progress. ASSUME ds:nothing PROC New13 far ; Int 13h (disk functions) intercepter pushf ; Preserve flags mov [Int13Busy],1 ; Set int 13h busy flag cmp dl,80h ; Check for hard drive 0 je AccessDrive0 ; If so cmp dl,81h ; Check for hard drive 1 je AccessDrive1 ; If so ; Jump to old handler GoOld13: popf ; Fix stack pushf ; Simulate interrupt DB 9Ah ; CALL xxxx:yyyy Old13Vec = THIS DWORD ; Vector to original handler Old13Ofs DW 0 ; Offset Old13Seg DW 0 ; Segment mov [Int13Busy],0 ; Clear busy flag retf 2 ; Return with flags returned by BIOS AccessDrive0: push [Park_Ticks] ; Get timeout count pop [ParkDrive0] ; Set timeout count for drive 0 jmp SHORT GoOld13 ; Chain AccessDrive1: push [Park_Ticks] ; Get timeout count pop [ParkDrive1] ; Set timeout count for drive 1 jmp SHORT GoOld13 ; Chain ENDP New13 ; Int 16h intercepter ---------------------------------------------------------- ; The int 16h intercepter provides the LOCK function on the typematic delay ; and rate. Function calls with AH=3 are related to typematic functions. ; The normal function to set the typematic parameters is AH=3, AL=5 with BL ; and BH containing the two parameters (delay and rate). ; According to version 39 of Ralf Brown's Interrupt List, only subfunctions ; 0-6 (in AL) exist. Subfunction 6 allows the typematic parameters to be ; requested on some machines; all other defined subfunctions relate to setting ; or modifying the typematic parameters. ; This intercepter intercepts all calls with AH=3 (i.e. all typematic related ; function calls) except AL=6 (request typematic parameters) and higher (these ; are currently undefined subfunctions) and replaces the call with AL=5 (set ; typematic parameters) using the 'locked' typematic parameters in BX. When ; it intercepts the function, it preserves the typematic parameters provided ; in BX and the function and subfunction numbers provided in AX so that they ; may be returned unchanged to the caller. ; There may be potential problems with intercepting the typematic functions if ; functions greater than 6 are added in future. At the moment, these will be ; passed through as normal. If they would result in a change to the typematic ; settings, then the lock function will not successfully lock the parameters. ; Alternative approaches would be: ; 1. Instead of replacing subfunctions 0-5 with subfunction 5, simply ignore ; these subfunctions. This would cause extra difficulty in setting the ; locked parameters from a transient copy of MODE. ; 2. Instead of passing undefined subfunctions (7 and higher) they could be ; intercepted in the same way or just ignored. This would cause trouble ; if the future subfunction was supposed to return values from the BIOS, ; because the BIOS function would not be called and the values would not ; be returned, though the caller is expecting them. ASSUME ds:nothing PROC New16 far ; Int 16h (keyboard funcs) intercepter pushf ; Preserve caller flags cmp ah,3 ; Check for typematic functions jne NoIntercept16 ; If not cmp al,6 ; Check for subfunctions 0-5 jb YesIntercept16 ; If so ; Do not intercept this function call NoIntercept16: popf ; Fix stack DB 0EAh ; JMP xxxx:yyyy Old16Vec = THIS DWORD ; Vector to original handler Old16Ofs DW 0 ; Offset Old16Seg DW 0 ; Segment ; Intercept this function call YesIntercept16: popf ; Fix stack push bx ; Keep parameters supplied by caller push ax ; Keep caller-supplied function too mov al,5 ; Use standard set typematic function DB 0BBh ; MOV BX,nnnn Type_Parm = THIS WORD ; Both typematic parameters Type_Rate DB 0FFh ; Typematic rate 0-31 MUST BE Type_Delay DB 0FFh ; Typematic delay 0-3 ADJACENT pushf ; Simulate an interrupt call [Old16Vec] ; Call old handler pop ax ; Restore AX provided by caller pop bx ; Restore BX provided by caller retf 2 ; Return flags returned by BIOS ENDP New16 ; Int 17h intercepter ---------------------------------------------------------- ; The int 17h intercepter provides the persistent (infinite timeout) function ; and redirection function for printer I/O. Up to four parallel ports are ; supported. Each printer port (LPT1-4) has a control byte, which is allocated ; as listed in the variable declarations for LPT_Ctrl. The port may be set ; for persistent mode, in which case this intercepter will continually retry ; if a timeout occurs while trying to send a character, and/or may be redirected ; to a serial port or to NUL, in which case this intercepter translates the ; specified request and calls the BIOS serial firmware functions (int 14h) or ; ignores the request. ; Other programs (e.g. TSRs, BIOS extensions) may hook into int 17h, but ; calls to these programs will have AH and/or DX out of range. AH is the ; function number, which may be 0 (send character), 1 (initialise port), or ; 2 (get status). DX is the port number, normally 0-2 for LPT1-3 but MODE ; will support up to LPT4 although DOS may not provide an LPT4 device. ASSUME ds:nothing PROC New17 far ; Int 17h (printer funcs) intercepter pushf ; Preserve those flags cmp ah,3 ; Check for invalid function jae NoIntercept17 ; If so, probably a TSR function cmp dx,4 ; Check for invalid port jae NoIntercept17 ; If so, probably a TSR function too ; Get port function control byte for the specified parallel port push bx ; Preserve mov bx,dx ; Port number mov bl,[LPT_Ctrl+bx] ; Get control byte for this port ; First check for redirection. If the port is redirected, handle this ; further on. test bl,00000111b ; Redirected? jnz IsRedirected ; If so ; Port is not redirected. If persistent retries are not specified, just chain ; to the normal int 17h handler. Also, if it's just a status call or an init ; printer call, chain to the normal handler too. This leaves the case where ; the function is send-character and persistent operation is specified. test bl,10000000b ; Persistent? jz NoInter17BX ; If not, just go to old int 17h handler test ah,ah ; Sending a character? jnz NoInter17BX ; If not, do old thing too ; Persistent operation specified on non-redirected port - call the old int 17h ; handler repeatedly until it returns successful (no timeout) PersistLoop: xor ah,ah ; Set zero function number (send char) pushf ; Simulate stack for interrupt call [cs:Old17Vec] ; Call original BIOS handler test ah,00000001b ; Timeout flag set? jnz PersistLoop ; If so, try again (and again...) jmp SHORT Return17BX ; Exit ; Port is redirected. Check for redirected to NUL - if so, just ignore the ; request and return a faked 'happy' status. Otherwise, check the function ; number. The possible functions are 0 (send character), 1 (initialise ; printer), and 2 (get status). Function 1 (init printer) has no meaning ; when used with a serial port; it just reports the status, so it will be ; treated the same as function 2. IsRedirected: cmp bl,7 ; Redirecting to NUL? jne RedirNotNUL ; If not mov ah,10010000b ; Happy happy jmp SHORT Return17BX ; Exit RedirNotNUL: dec bx ; Get serial port (0-3) to redirect to push dx ; Keep original port number mov dl,bl ; Get serial port number and dl,01111111b ; Turn off the persistent bit in DL test ah,ah ; Check function number jnz Redir_GetStat ; If not zero (get status) ; Now sending a character to a redirected port. Convert the call first, and ; after it completes, if a timeout was flagged, check whether the port was set ; for persistent retries, and retry if so. During all this stuff, DX contains ; the redirected serial port number, not the original parallel port number. SerialPersist: mov ah,1 ; Function to send character (serial) int 14h ; Send it test ah,10000000b ; Successful? jz Redir_GetStat ; If so test bl,10000000b ; Persistent behaviour? jnz SerialPersist ; If so, just try again etc etc mov bh,10000000b ; Flag that we had a timeout ; Had an error sending a character to the redirected port - just return ; the status byte normally - fall through... ; Request status of redirected port. The persistence flag is not relevant. ; The status is returned in AH, in the form: ; ; 7 6 5 4 3 2 1 0 ; * . . . . . . . Printer ready (1 = ready, 0 = not ready; busy) ; . * . . . . . . Acknowledgement from printer, returned as 0 ; . . * . . . . . Out of Paper from printer, returned as 0 ; . . . * . . . . Selected signal from printer, returned as 1 ; . . . . * . . . I/O error, returned as 0 ; . . . . . * * . Not used, returned as 0 ; . . . . . . . * Timeout error flag (true if set) Redir_GetStat: push ax ; Keep whatever was in AL mov ah,3 int 14h ; Request serial port status ; Serial function 3 gets the line status and modem status registers to AH ; and AL respectively. I will use the CTS line, reported in bit 4 of AL, ; to indicate whether the printer is ready. Bit 7 of AH reports the serial ; timeout error. Now construct the appropriate printer status: r001000t ; where 'r' is the ready flag and 't' is the timeout error flag. or ah,bh ; OR in timeout from serial function 1 shl ah,1 ; Get timeout flag to carry mov ah,00001000b ; Get initial value shifted right once rcl ah,1 ; Incorporate timeout flag test al,00010000b ; Is CTS active? jz NoCTS ; If not or ah,10000000b ; If so, set the ready flag NoCTS: pop bx ; Get original AL value to BL mov al,bl ; Restore AL as provided to call ; Restore registers and return with result code in AH Return17DXBX: pop dx ; Restore DX Return17BX: pop bx ; Restore BX popf ; Restore flags iret ; Return to caller ; Pass the function call on to the BIOS int 17h handler NoInter17BX: pop bx ; Restore NoIntercept17: popf ; Fix stack DB 0EAh ; JMP xxxx:yyyy Old17Vec = THIS DWORD ; Vector to original handler Old17Ofs DW 0 ; Offset Old17Seg DW 0 ; Segment ENDP New17 ; TSR support ------------------------------------------------------------------ ; TSR residency detection is via int 2Fh. When the transient copy wants to ; locate a resident copy of itself, if one exists, it issues int 2Fh with ; registers set as follows: AX = 0F73Fh, BX = 484Bh, ES = segment-paragraph ; of transient copy. ; The resident int 2Fh handler compares its own signature to the signature of ; the transient copy (the segment of the transient copy is provided in the ES ; register by the caller), and if they do not match, chains to the previous ; owner of int 2Fh. If the signatures do match, the handler sets ES to the ; segment-paragraph of the resident copy, sets BX to 4D4Ah and returns. The ; signature is assumed to start at offset 100h into the segment and must at ; least contain the program name and version number. ASSUME ds:nothing PROC New2F far pushf sti ; Enable hardware interrupts cmp ax,0F73Fh ; Calling me? jne NotForMe ; If not cmp bx,484Bh ; Check BX too jne NotForMe ; If not push ds ; Preserve these regs push di push si push cx push cs ; Set DS to this segment pop ds mov si,OFFSET Main ; Point to our signature mov di,si ; Point to possible transient signature mov cx,SigLen ; Number of chars to compare cld ; Upwards compare direction repe cmpsb ; Compare signatures pop cx ; Restore registers pop si pop di pop ds jne NotForMe ; If signatures did not match mov bx,4D4Ah ; Flag acknowledgement push cs pop es ; Set ES to resident segment popf ; Restore flags iret ; Return to caller NotForMe: popf ; Restore flags DB 0EAh ; JMP xxxx:yyyy Old2FVec = THIS DWORD ; Vector to original handler Old2FOfs DW 0 ; Offset Old2FSeg DW 0 ; Segment ENDP New2F ; End of resident / start of transient ========================================= MASM Discard = $ ; Start of transient portion TSRParas = (OFFSET (Discard-@curseg+15) SHR 4) prexp <Resident size:> %(TSRParas SHL 4) < bytes> IDEAL ; Transient messages ----------------------------------------------------------- ; Note - I have used American spelling ("color") in the help text but not ; in the internal comments or labels. DOSVersMsg DB AppName,": Requires DOS version 2.0 or later",NL,"$" MemoryEM DB 162,AppName,": Insufficient memory",NL,0 UsageEM DB 255,NL,AppName," -- Free-DOS mode setting and miscellaneous utility Version ",Ver+"0",".",SubVer+"0",".",ModVer+"0",", ",VerDate DB NL,9,"(c) Copyright 1994-1995 by K. Heidenstrom (kheidens@actrix.gen.nz)" DB NL DB NL,AppName," Videomode[,Lines] - Select video mode and lines, Videomode may be:" DB NL,9,9,"MONO",9,9,"- 80-column monochrome (MDA and Hercules)" DB NL,9,9,"BW40, BW80",9,"- 40-column and 80-column color-suppressed CGA" DB NL,9,9,"CO40, CO80",9,"- 40-column and 80-column color" DB NL,9,"Lines may be 25, 43, or 50 (43 requires EGA or VGA, 50 requires VGA)" DB NL,AppName," COMn:r,p,d,s - Set serial port parameters (not permanent):" DB NL,9,"n = port number (1-4)" DB NL,9,"r = baud rate (50, 110, 150, 300, 600, 1200, 2400, 4800, 9600," DB NL,9,9,"14400, 19200, 28800, 38400, 57600, 115200, abbreviations)" DB NL,9,"p = parity (e = even, n = none, o = odd)" DB NL,9,"d = data bits (5-8)" DB NL,9,"s = stop bits (1-2)" DB NL,AppName," LPTn:P - Infinite timeout on parallel port (1-4) (",AppName," will go resident)" DB NL,AppName," LPTn:=COMx - Redirect printer output to COM port (",AppName," will go resident)" DB NL,AppName," LPTn:=NUL: - Redirect printer output to NUL (",AppName," will go resident)" DB NL,AppName," LPTn: - Remove redirection and infinite timeout on parallel port" DB NL,AppName," PARK[,minutes[:seconds]] - Park now or after idle (",AppName," will go resident)" DB NL,AppName," DELAY=d RATE=r [LOCK] - Set keyboard typematic delay and rate:" DB NL,9,"d = delay (1-4) r = rate (1-32) LOCK = permanent (will go resident)" DB NL,0 BadCmdModeEM DB 246,AppName,": Only one command allowed per invocation",NL,0 OutRangeEM DB 241,AppName,": Parameter out of range - check the help text",NL,0 LinesVModeEM DB 242,AppName,": 43-line and 50-line modes are only usable with CO80 mode",NL,0 BadBaudEM DB 243,AppName,": Unknown baud rate specified",NL,0 TypeParamEM DB 244,AppName,": Must specify both DELAY and RATE for typematic setting",NL,0 NoSuchSPortEM DB 115,AppName,": Specified serial port does not exist",NL,0 SerialSetMsg DB AppName,": Serial port parameters set (not locked)",NL,"$" SetNormalMsg DB AppName,": LPT" SetNormalLPT DB "1 set to normal mode",NL,"$" NoHDiskEM DB 117,AppName,": No hard drive(s) found to park!",NL,0 Parked1Msg DB AppName,": Hard drive has been parked, switch off or press Ctrl-C to return to DOS",NL,"$" Parked2Msg DB AppName,": Hard drives have been parked, switch off or press Ctrl-C to return to DOS",NL,"$" ParkInst1Msg DB AppName,": Timed park function installed for one hard drive, ",AppName," is resident",NL,"$" ParkInst2Msg DB AppName,": Timed park function installed for two hard drives, ",AppName," is resident",NL,"$" ParkResMsg DB AppName,": Timed park timeout parameter updated in resident copy",NL,"$" ParkEnab1Msg DB AppName,": Timed park function enabled in resident copy for one hard drive",NL,"$" ParkEnab2Msg DB AppName,": Timed park function enabled in resident copy for two hard drives",NL,"$" TypeSetMsg DB AppName,": Typematic parameters set (not locked)",NL,"$" LockInstMsg DB AppName,": Typematic parameters locked, resident portion of ",AppName," installed",NL,"$" ResLockedMsg DB AppName,": Typematic parameters now locked by resident portion of ",AppName,NL,"$" TResUpdateMsg DB AppName,": Locked typematic parameters updated",NL,"$" UnsuppVidEM DB 118,AppName,": Specified video mode is not supported on this machine",NL,0 SetPersistMsg DB AppName,": Parallel port set for infinite retry on timeout",NL,"$" SetRedNULMsg DB AppName,": Parallel port redirected to NUL:",NL,"$" SetRedirMsg DB AppName,": Parallel port redirected to COM" SetRedirCOM DB "0",NL,"$" ResInstallMsg DB AppName,": Resident portion of MODE is now installed",NL,"$" ; Transient tables ------------------------------------------------------------- ; Command table - all entries are in lower case and will be compared to the ; characters from the command line ORed with 00100000 binary. CmdTable: DBBW "mono",0,Param_MONO DBBW "bw40",0,Param_BW40 DBBW "bw80",0,Param_BW80 DBBW "co40",0,Param_CO40 DBBW "co80",0,Param_CO80 DBBW "com",0,Param_Com DBBW "lpt",0,Param_LPT DBBW "park",0,Param_PARK DBBW "delay=",0,Param_DELAY DBBW "rate=",0,Param_RATE DBBW "lock",0,Param_LOCK DB 0 ; End of table marker ; Despatch table ModeTbl DW BadUsage ; No parameters DW DoMode_Vid ; Set video mode (and lines) DW DoMode_Com ; Set serial port parameters DW DoMode_LPT ; Redirect parallel port or no timeout DW DoMode_Park ; Park now or after an idle period DW DoMode_Typematic ; Set typematic parameters ; Baud rate table - the value read from the command line is 16-bit therefore ; 115200 will appear as 49664 (115200 % 65536). Therefore if the user enters ; 49664 bps, this will be interpreted as 115200 bps rather than flagging an ; error. ; This table takes care of minimal text abbreviations, e.g. 96 for 9600 bps. ; The second number in each entry is the raw baud rate divisor value. ; I initially used DW 115200 / rate but TASM gives incorrect results (but no ; error message, though!) so I had to divide the 115200 and the baud rates ; by 10 in each calculation. BaudTbl: DW 12, 11520/120 ; 1200 DW 14, 11520/1440 ; 14400 DW 19, 11520/1920 ; 19200 DW 24, 11520/240 ; 2400 DW 28, 11520/2880 ; 28800 DW 38, 11520/3840 ; 38400 DW 48, 11520/480 ; 4800 DW 50, 11520/5 ; 50 DW 57, 11520/5760 ; 57600 DW 96, 11520/960 ; 9600 DW 110, 11520/11 ; 110 DW 115, 11520/11520 ; 115200 DW 144, 11520/1440 ; 14400 DW 150, 11520/15 ; 150 DW 192, 11520/1920 ; 19200 DW 288, 11520/2880 ; 28800 DW 300, 11520/30 ; 300 DW 384, 11520/3840 ; 38400 DW 576, 11520/5760 ; 57600 DW 600, 11520/60 ; 600 DW 1152, 11520/11520 ; 115200 DW 1200, 11520/120 ; 1200 DW 2400, 11520/240 ; 2400 DW 4800, 11520/480 ; 4800 DW 9600, 11520/960 ; 9600 DW 14400, 11520/1440 ; 14400 DW 19200, 11520/1920 ; 19200 DW 28800, 11520/2880 ; 28800 DW 38400, 11520/3840 ; 38400 DW 49664, 11520/11520 ; 115200 % 65536 = 49664 DW 57600, 11520/5760 ; 57600 DW 65535, 11520/960 ; End of table ; LPT subfunction table - used after LPTn has been parsed to determine ; which of the LPT subfunctions are requested - persistent, back to normal, ; or redirect. LPTTable: DBBW ":=com",0,LPT_Redirect DBBW ":=nul:",0,LPT_RedNUL DBBW ":=nul",0,LPT_RedNUL DBBW ":p",0,LPT_Persist DBBW ":",0,LPT_Normal DB 0 ; End of table marker ; Video BIOS function 1A00h returns display combination codes in BL and BH. ; BL contains the DCC for the active display, BH contains the DCC for the ; inactive display. The following table maps DCC values to bitflags for the ; modes that are supported, which will be ORed into the VidHave variable that ; indicates what modes are acceptable. I'm not sure what the story is with ; the PGA and the MCGA. They may support 43-line mode. ; ; References: ; ; Programmer's Guide to PC & PS/2 Video Systems ; Copyright 1987 by Richard Wilton ; Published by Microsoft Press ; ISBN 1-55615-103-9 ; ; EGA/VGA A Programmer's Reference Guide ; Copyright 1988 by Bradley Dyck Kliewer ; Published by Intertext Publications, McGraw-Hill Book Company, New York, NY ; ISBN 0-07-035089-2. Library of Congress Catalog Card number 87-83102. Vid_50 = 8 ; ┌───── Supports 50 lines in mode 3 Vid_43 = 4 ; │┌──── Supports 43 lines in mode 3 Vid_3 = 2 ; ││┌─── Supports mode 0-3 Vid_7 = 1 ; │││┌── Supports mode 7 ; ││││ DCCTable DB 00000000b ; 0 No display adapter DB 00000001b ; 1 MDA/Hercules DB 00000010b ; 2 CGA DB 00000000b ; 3 Reserved DB 00000111b ; 4 EGA DB 00000111b ; 5 EGA with monochrome monitor DB 00000011b ; 6 PGA (Professional Grph. Adapter) DB 00001111b ; 7 VGA with monochrome monitor DB 00001111b ; 8 VGA with colour display DB 00000000b ; 9 Reserved DB 00000011b ; 10 MCGA with digital colour monitor DB 00000011b ; 11 MCGA with monochrome monitor DB 00000011b ; 12 MCGA with colour monitor ; Transient data --------------------------------------------------------------- Already DW 0 ; Segment-para of resident copy or zero ; Command line modes: Mode_None = 0 Mode_Vid = 2 ; Set video mode (and lines) Mode_Com = 4 ; Set serial port parameters Mode_LPT = 6 ; Redirect parallel port or no timeout Mode_Park = 8 ; Park now or after an idle period Mode_Typematic = 10 ; Set typematic parameters ; Note - several of these byte parameters have an extra zero byte; this is ; because they are sometimes accessed as words. CmdMode DB 0,0 ; Command line mode - one of above Vid_Mode DB 0FFh,0 ; Video mode number for Mode_Vid Vid_Lines DB 0 ; Number of lines (0=25, 1=43, 2=50) VidHave DB 0 ; Video adapter mode flags Com_Port DB 0FFh,0 ; Port number for Mode_Com Com_BRD DW 0 ; Baud rate divisor Com_LCR DB 0 ; Line control register value LPT_Port DB 0FFh,0 ; Port number for Mode_LPT LPT_Func DB 0,0 ; 1-4 = redirect, 80h = persist, ; 0 = return to normal operation Type_Lock DB 0 ; Typematic lock flag (0/1) ; Transient code =============================================================== ASSUME ds:ComFile PROC Main2 near mov ah,30h int 21h cmp al,2 ; Expect DOS 2.0 or later jae DOS_Ok mov dx,OFFSET DOSVersMsg mov ah,9 int 21h int 20h BadUsage: point bx,UsageEM ; Incorrect usage ; Errexit code - aborts the program with a specified message and errorlevel. ; On entry, BX points to a control string within the current code segment, ; which consists of a one-byte errorlevel followed by a null-terminated error ; message which may be blank. This code assumes DOS version 2.0 handle ; functions are supported. After writing the error message to StdErr, DOS ; function 30h (terminate with return code) is used to terminate the program. ErrExit: push [WORD cs:bx] ; Errorlevel onto stack inc bx ; Point to error message call ErrWriteMsg ; Display pop ax ; Errorlevel ErrExitQ: mov ah,4Ch int 21h ; Terminate with errorlevel in AL ErrWriteMsg: mov cx,2 ; Handle of Standard Error device WriteMsg: push cs pop ds ; Make DS valid mov dx,bx ; Point DX for later Err_Parse1: inc bx ; Bump pointer cmp [BYTE ds:bx-1],0 ; Hit null terminator yet? jnz Err_Parse1 ; If not, loop xchg cx,bx ; Get address of null terminator sub cx,dx ; Subtract offset of start of text dec cx ; Adjust to correct number of chars jz Err_Parse2 ; If no text present mov ah,40h ; Function to write to file or device int 21h ; Write error message to StdErr Err_Parse2: ret ; Return to exit code or whoever ; Check amount of available memory --------------------------------------------- DOS_Ok: mov ax,cs ; Get current segment DB 5 ; ADD AX,nnnn (avoid TASM warning!) DW MemParas ; Get paragraph past end of program cmp ax,[WORD ds:2] ; Check against paragraph of mem top mov bx,OFFSET MemoryEM ; Prepare for error jae ErrExit ; If not enough memory point sp,WorkStackTop ; Relocate stack to safe area ; Detect resident copy --------------------------------------------------------- ; This code locates the resident copy of this program, if any. It modifies ; the first three bytes of the program image then calls int 2Fh to look for ; a response from a resident handler for the same program. If a resident copy ; was found, ES contains the segment-paragraph of the resident copy. Note ; that the signature is completed manually here - this ensures that only ; copies of this program which have actually _executed_ will have the correct ; signature, and copies which are in disk buffers will not. Though this is not ; really required (due to the int 2Fh residency check method), it is tidy. mov [WORD Main],"TS" ; Complete the signature mov [BYTE Main+2],"D" mov ax,0F73Fh mov bx,484Bh int 2Fh ; TSR installation check cmp bx,4D4Ah jne NoResident mov [Already],es ; Store segment-para of resident copy NoResident: ; Command tail parsing --------------------------------------------------------- ; Scan the command tail for the start of a text token, then locate the token ; in the command table CmdTable. If not found, issue usage error message. ; If found, call the parameter handler, with SI pointing past the part of the ; token that matched the command table entry. The handler function will return ; if no error was found. The parameter handler may jump to BadUsage or ErrExit ; to abort the program with a syntax message or a specific error message. ; On return from the parameter handler (i.e. if no error was found), SI points ; past the text processed as part of the parameter, and should point to ; whitespace or the C/R that terminates the command tail. push cs pop es ; Make sure ES addresses to ComFile cld ; Upwards string direction mov si,81h ; Prepare for command tail parsing Parameter: lodsb ; Next character cmp al,13 ; Check for end of command tail je DoneParms ; If so cmp al," " ; Check for space or other whitespace jbe Parameter ; Skip it dec si ; Point to first char of parameter point di,CmdTable ; Point to start of command table call StringLCComp ; Find a match in the command table call bx ; Call appropriate handler or BadUsage jmp SHORT Parameter ; Next parameter ; Reached end of command line DoneParms: push cs pop es ; Make sure ES points to transient copy mov bx,[WORD CmdMode] ; Get mode format number jmp [ModeTbl+bx] ; Go to appropriate handler ENDP Main2 ; Parameter handlers =========================================================== ; These handlers are called with SI pointing just past the end of the command ; token that was scanned. If the handler detects an error it may jump to ; BadUsage (syntax errors) or ErrExit (for specific errors). If no problems ; were found, it returns with SI pointing to the next character to be scanned, ; which may be whitespace or the final C/R at the end of the command tail. ; The handler is responsible for making sure that it doesn't scan past the ; terminating C/R unless this will cause an error, in other words if the ; handler returns, it must not scan past the final C/R - if it finds the end ; of the command tail during processing without an error, it must return with ; SI pointing to the terminating C/R. ; Video parameter handlers ----------------------------------------------------- ; Video mode setting handlers - these check for more than one mode provided ; on the command line and parse the optional ,nn number of lines, but do not ; check that the specified mode is valid for the video adapter(s) present. ; If the ,nn parameter is present, the mode must be CO80 otherwise an error ; is reported. PROC VidParams near ; All video mode parameters Param_BW40: mov al,0 ; Colour-suppressed 40-column mode DB 3Dh ; Skip next two-byte instruction Param_CO40: mov al,1 ; Colour 40-column mode DB 3Dh ; Skip next two-byte instruction Param_BW80: mov al,2 ; Colour-suppressed 80-column mode DB 3Dh ; Skip next two-byte instruction Param_CO80: mov al,3 ; Colour 80-column mode (incl 43/50) DB 3Dh ; Skip next two-byte instruction Param_MONO: mov al,7 ; Monochrome video mode ; AL = desired video mode number - check that mode has not already been given xchg al,[Vid_Mode] ; Set video mode number inc al ; Make sure there wasn't one already jnz BadUsage1 ; If there was ; Check for optional number of lines cmp [BYTE si],"," ; Check for optional number of lines jne VidParam_Done ; If no error inc si ; Skip comma call ReadDecimal ; Get the number sub ax,25 ; Check for 25 lines jz LinesOK ; If so sub ax,43-25-1 ; Convert 43 to 1 cmp ax,1 ; Check for it je LinesOK ; If correct sub ax,50-43-1 ; Convert 50 to 2 cmp ax,2 ; Check for it je LinesOK ; If so jmp OutOfRange ; Go to out of range error stuff LinesOK: mov [Vid_Lines],al ; Store (0/1/2) test ax,ax ; Check for 25-line jz VidParam_Done ; If so, don't require CO80 cmp [Vid_Mode],3 ; Only allow 43/50-line mode with CO80 point bx,LinesVModeEM ; Prepare for error jne GoErrExit ; If error VidParam_Done: mov al,Mode_Vid ; Get mode jmp CheckMode ; Set command mode, check for conflict BadUsage1: jmp BadUsage ENDP VidParams ; Serial port parameter handler ------------------------------------------------ PROC Param_Com near mov cx,4*256+1 ; Adjust by 1, check against 4 call GetAdjCheck ; Get parameter, adjust and check xchg al,[Com_Port] ; Store, get old value inc al ; Check for multiple commands jz ComPortOK ; If alright jmp BadCmdMode ; If more than one port command ComPortOK: lodsb ; Get colon cmp al,":" ; Validate jne BadUsage1 ; If wrong call ReadDecimal ; Parse baud rate point bx,BaudTbl-4 ; Point to before baud rate table NextBaud: add bx,4 ; Bump pointer cmp ax,[bx] ; Does value match? ja NextBaud ; If not, keep looking je GotBaud ; If so BadBaudRate: point bx,BadBaudEM ; Scanned whole table - bad baud rate GoErrExit: jmp ErrExit ; Go to error exit GotBaud: mov ax,[bx+2] ; Get baud rate divisor value mov [Com_BRD],ax ; Store it call SkipComma ; Check for and skip a comma lodsb ; Get odd/even/none or al,00100000b ; Convert to lower case cmp al,"n" ; Check for none je GotParity ; If so cmp al,"o" ; Check for odd je SetParity ; If so cmp al,"e" ; Check for even jne BadUsage1 ; If bad syntax or [Com_LCR],00010000b ; Set even parity select SetParity: or [Com_LCR],00001000b ; Set parity enable GotParity: call SkipComma ; Skip next comma mov cx,4*256+5 ; Adjust by 5, check against 4 call GetAdjCheck ; Get parameter, adjust and check it or [Com_LCR],al ; Combine into LCR value call SkipComma ; Skip next comma mov cx,2*256+1 ; Adjust by 1, check against 2 call GetAdjCheck ; Get parameter, adjust and check it shl al,1 ; Shift bit shl al,1 ; to b2 or [Com_LCR],al ; Combine into LCR value mov al,Mode_Com ; Get mode jmp CheckMode ; Set command mode, check for conflict ENDP Param_Com ; Parallel port parameter handler ---------------------------------------------- PROC Param_LPT near mov cx,4*256+1 ; Adjust by 1, check against 4 call GetAdjCheck ; Get parameter, adjust and check xchg al,[LPT_Port] ; Store, get old value inc al ; Check for multiple commands jnz BadCmdMode ; If more than one port command point di,LPTTable ; Point to subfunction table call StringLCComp ; Scan for subfunction jmp bx ; Go to appropriate handler or BadUsage LPT_Redirect: mov cx,4*256+1 ; Adjust by 1, check against 4 call GetAdjCheck ; Get parameter, adjust and check it inc ax ; Convert 0-3 to 1-4, port num in b0-2 DB 3Dh ; Skip next two-byte instruction LPT_RedNUL: mov al,7 ; Fake redirection to NUL as COM7 DB 3Dh ; Skip next two-byte instruction LPT_Persist: mov al,10000000b ; Persistent DB 3Dh ; Skip next two-byte instruction LPT_Normal: mov al,0 ; 'Back to normal' action code GotLPTFunc: mov [LPT_Func],al ; Store LPT action code mov al,Mode_LPT ; Get command mode jmp SHORT CheckMode ; Set command mode, check for conflict ENDP Param_LPT ; Hard disk park parameter handler --------------------------------------------- Param_PARK: cmp [BYTE si],"," ; Check for optional idle timeout jne NoIdle ; If not inc si ; Skip comma mov cx,51*256 ; Limit it to 50 minutes call GetAdjCheck ; Get and check minutes mov dx,1092 ; Number of ticks in one minute (approx) mul dx ; Get number of ticks mov [Park_Ticks],ax ; Store cmp [BYTE si],":" ; Check for colon and seconds jne NoSeconds ; If not inc si ; Skip colon mov cx,60*256 ; Limit it to 59 seconds call GetAdjCheck ; Get and check seconds mov dx,18 ; Number of ticks in one second (approx) mul dx ; Get number of ticks add [Park_Ticks],ax ; Store NoSeconds: cmp [Park_Ticks],0 ; Check we got something jz OutOfRange ; If out of range NoIdle: mov al,Mode_Park ; Get mode jmp SHORT CheckMode ; Set command mode, check for conflict BadCmdMode: point bx,BadCmdModeEM ; Error - more than one command type jmp ErrExit ; Go to error exit stuff ; Typematic parameter handlers ------------------------------------------------- Param_DELAY: mov cx,4*256+1 ; Adjust by 1, check against 4 call GetAdjCheck ; Read, adjust and check parameter xchg al,[Type_Delay] ; Set it, get old value inc al ; Check for only DELAY= parameter jnz BadUsage2 ; If not jmp SHORT Typematic Param_RATE: mov cx,32*256+1 ; Adjust by 1, check against 32 call GetAdjCheck ; Read, adjust and check parameter neg al ; Convert to negative add al,31 ; Convert 0-31 to 31-0 xchg al,[Type_Rate] ; Set it, get old value inc al ; Check for only RATE= parameter jnz BadUsage2 ; If not jmp SHORT Typematic Param_LOCK: mov [Type_Lock],1 ; Set lock flag Typematic: mov al,Mode_Typematic ; Command mode ; Check and set command mode --------------------------------------------------- CheckMode: xchg al,[CmdMode] ; Set it test al,al ; Check that it was previously zero jz ARet1 ; If so cmp al,[CmdMode] ; Command mode same as before? je ARet1 ; If so jmp SHORT BadCmdMode ; If not, error! ARet1: ret BadUsage2: jmp BadUsage ; Go to bad usage exit point ; String matcher --------------------------------------------------------------- ; This function accepts a string at SI and a pointer to a table in DI, and ; scans the table for a matching string. Each entry in the table consists of ; a lower-case string, with a null-terminator, followed by a two-byte value ; that will be returned by this function if a match is found (successful). ; The end of the table is marked by a zero-length string. The strings in the ; table are in lower case and the case of the source string will be converted ; by ORing each character with 00100000b. Note that this will produce some ; unexpected effects on characters which are not alphabetic - for example, a ; space will be translated into a "0" (among others!) ; In: SI -> String to be matched ; DI -> Table of strings to match with, format as described above ; Out: CF = Success/failure: NC = Success, CY = Failure ; BX = Value from table if successful, otherwise points to BadUsage ; SI unchanged if unsuccessful, points past matched string if successful ; Note: ES and DS must be equal PROC StringLCComp near StrLCComp1: xor bx,bx ; Zero index StrLCComp2: mov al,[si+bx] ; Char from source string or al,00100000b ; Convert to lower case cmp al,[di+bx] ; Match? je StrLCComp4 ; If so xor al,al ; Null char StrLCComp3: scasb ; Check for terminator on table entry jnz StrLCComp3 ; If not yet inc di inc di ; Skip return parameter cmp [BYTE di],0 ; Scanned whole table? jnz StrLCComp1 ; If not, try next entry stc ; If so, set carry indicating no match point bx,BadUsage ; No match - set pointer to BadUsage ret StrLCComp4: inc bx ; Next position cmp [BYTE di+bx],0 ; Has whole parameter matched? jnz StrLCComp2 ; If not, keep checking add si,bx ; Skip matched string, clear carry mov bx,[di+bx+1] ; Get parameter from table ret ; Return carry clear - successful ENDP StringLCComp ; Decimal input ---------------------------------------------------------------- ; This function calls ReadDecimal to parse a decimal formatted ASCII number ; at DS:SI, then adjusts the number by subtracting the value provided in CL ; and validates the result against the value provided in CH; if the value ; is greater than or equal to the value in CH, it aborts the program with the ; parameter out of range error message. It returns the result in AL. ; AX, BX, DX and SI are destroyed. The parameter before and after adjustment ; is not allowed to exceed 255. PROC GetAdjCheck near call ReadDecimal test ah,ah ; Greater than 255? jnz OutOfRange ; If so sub al,cl ; Adjust cmp al,ch ; Check against limit + 1 jae OutOfRange ; If bad ret ; If alright OutOfRange: point bx,OutRangeEM ; If not, illegal number given jmp ErrExit ; Go to error exit stuff ENDP GetAdjCheck ; This function scans a number in ASCII format from the command tail and returns ; the binary equivalent of the number. It is limited to numbers in the range 0 ; to 65535, and does not distinguish 'no number found' from 'zero found' (both ; return zero result). Before calling, SI must point to the first character to ; be scanned. On return, SI will point past the last valid character, i.e. to ; the character which terminated the evaluation, and AX will contain the result. ; The function destroys AX, BX, DX, and SI, and assumes that DF is clear. PROC ReadDecimal near xor bx,bx ; Clear result ReadNumLp: lodsb ; Get a character sub al,"0" ; Convert "0"-"9" to 0-9 cmp al,10 ; Check for valid char jae ReadNumFin ; If not, terminator cbw ; Zero AH xchg ax,bx ; New digit to BL, old total to AX mov dx,10 ; Ten to unused register mul dx ; Multiply old value by ten add bx,ax ; Add to new digit jmp SHORT ReadNumLp ; Loop for more ReadNumFin: dec si ; Point to just past number xchg ax,bx ; Return value in AX ret ; Finished ENDP ReadDecimal ; Skip comma ------------------------------------------------------------------- PROC SkipComma near cmp [BYTE si],"," ; Check for comma jne BadUsage2 ; If not inc si ; Skip it ret ENDP SkipComma ; Command mode handlers ======================================================== ; After the command tail has been processed by the parameter handler functions, ; the appropriate command mode handler is called to perform the desired MODE ; operation. At this point, the command type has been determined, the command ; tail has been parsed and parameters have been processed and syntax-checked, ; and the appropriate variables have been set. ; Video command handler -------------------------------------------------------- ; First, determine the hardware configuration. The following adapters will be ; supported: EGA or VGA, MDA/Hercules, CGA, and a system with both CGA and ; MDA/Hercules. PROC DoMode_Vid near mov ax,1A00h int 10h ; Get display combination code (EGA/VGA) cmp al,1Ah ; Will be equal if supported jne NoDCCFunc ; If unsupported push bx ; Keep inactive monitor parms xor bh,bh ; Zero hibyte cmp bl,13 ; Check for valid DCC jae BadDCC1 ; If bad mov al,[DCCTable+bx] ; Get flags for this display type or [VidHave],al ; Enable those features BadDCC1: pop bx ; Restore inactive monitor data in BH mov bl,bh ; To BL xor bh,bh ; Zero hibyte again cmp bl,13 ; Check for valid DCC jae BadDCC2 ; If bad mov al,[DCCTable+bx] ; Get flags for this display type or [VidHave],al ; Enable those features BadDCC2: jmp SHORT GotDisplay ; We know what displays are present ; Function 1A00h (get display combination) did not work - we have a CGA, MDA ; or Hercules, or old EGA card. Now try function 12h, subfunction 10h (in BL). ; This returns the amount of video RAM, default mode (colour/monochrome) and ; feature and configuration bits, for the EGA and VGA. NoDCCFunc: mov ax,1200h ; Function 12h mov bx,0FF10h ; Subfunction code in BL int 10h ; Get some EGA/VGA information inc bh ; See whether anything happened jz NoEGAFunc ; If nothing happened or [VidHave],Vid_43+Vid_3+Vid_7 ; 43-line, colour and mono jmp SHORT GotDisplay ; We know what display is present ; Oh dear, this poor user has a MDA/Hercules and/or CGA card! Look for a CRTC ; at the two standard addresses - 3B4h for MDA/Hercules, and 3D4h for CGA. NoEGAFunc: mov dx,3B4h ; Try for monochrome first call TestForCRTC ; Is there a CRTC there? jne NoCRTC1 ; If not or [VidHave],Vid_7 ; If so, we can support monochrome mode NoCRTC1: mov dx,3D4h ; Try for colour call TestForCRTC ; Is there a CRTC there? jne NoCRTC2 ; If not or [VidHave],Vid_3 ; If so, we can support colour modes NoCRTC2: ; We now know which video modes are allowed - this is determined by VidHave. ; Now make sure that the desired mode is allowed. First, check for 43-line ; and 50-line modes specified and reject the request if not appropriate. GotDisplay: cmp [Vid_Lines],1 ; 43-line or 50-line specified? jb Not43_50 ; If not ; Either 43-line or 50-line mode was specified - therefore it must be ; standard colour mode (mode 3, CO80). Now check that 43-line or 50-line ; mode is allowed on this machine. ja Test_50 ; If 50-line test [VidHave],Vid_43 ; Is 43-line - is it allowed? jnz VModeOK ; If so, continue Test_50: test [VidHave],Vid_50 ; Is 50-line - is it allowed? jnz VModeOK ; If so BadVideo: point bx,UnsuppVidEM ; Error - video mode is not supported jmp ErrExit ; Go to standard error exit stuff Not43_50: cmp [Vid_Mode],4 ; Check for colour mode specified jae NotColour ; If not test [VidHave],Vid_3 ; Are colour modes allowed? jz BadVideo ; If not jmp SHORT VModeOK ; Continue NotColour: test [VidHave],Vid_7 ; Is monochrome mode allowed? jz BadVideo ; If not ; If the system does not have EGA/VGA (i.e. the Vid_43 bit in VidHave is clear) ; it may be necessary to modify the equipment list byte at 0000:0410 according ; to the type of video mode required. VModeOK: test [VidHave],Vid_43+Vid_50 ; Have EGA or better? jnz LeaveEquip ; If so xor ax,ax mov ds,ax ; Address BDA with DS ASSUME ds:nothing mov al,[ds:410h] ; Get equipment list byte and al,11001111b ; Mask off adapter type bits or al,00100000b ; Set bit for CGA cmp [Vid_Mode],7 ; Check for mono jne NoEquipMono ; If not or al,00110000b ; Set bits for MONO NoEquipMono: mov [ds:410h],al ; Store it back push cs pop ds ASSUME ds:ComFile ; If this is a VGA system, we must select the number of scan lines first, ; using video BIOS function 12h (in AH) subfunction 30h (BL). This accepts ; a number in AL which determines the number of scan lines. This number ; will be 1 for 43-line mode, to select 350 scan lines, or 2 for 25-line ; and 50-line modes, to select 400 scan lines. ; There are three possible values for Vid_Lines. They map as follows: ; ; Vid_Lines Char lines Value in AL Scan lines ; 0 25 2 400 ; 1 43 1 350 ; 2 50 2 400 LeaveEquip: cmp [Vid_Mode],3 ; Check for CO80 specified jne NoSetScanlines ; If not test [VidHave],Vid_50 ; Scan lines function supported? jz NoSetScanlines ; If not mov ah,12h ; Function for setting scan lines mov bl,30h ; For alphanumeric mode mov al,[Vid_Lines] ; 43-line = 1 = 350, 50-line = 2 = 400 shr al,1 ; Set carry if 43-line mov al,2 ; Prepare for 25-line or 50-line sbb al,0 ; Decrement if it was 43-line int 10h ; Set number of scan lines ; Finally, select the specified mode. If 43-line or 50-line mode, load the ; 8x8 ROM character set. NoSetScanlines: mov ax,[WORD Vid_Mode] ; Get the specified mode xor bx,bx ; Page zero int 10h ; Set it cmp [Vid_Lines],0 ; 43-line or 50-line? jz NoLoad8x8 ; If not mov ax,1112h ; Load 8x8 ROM character set int 10h ; Do it NoLoad8x8: jmp Exit0 ; Finished ENDP DoMode_Vid ; The following function tries to determine whether a CRTC (CRT controller ; chip used in video cards) exists at the I/O base address specified in DX ; on entry. If a CRTC is found, it returns with the zero flag set, otherwise ; it returns with the zero flag clear. PROC TestForCRTC near mov al,0Fh ; Use cursor location low byte cli ; No nasty interrupts please out dx,al ; Select the register inc dx ; Point to the register in al,dx ; Get current value jmp SHORT $+2 ; Short delay jmp SHORT $+2 ; And another mov ah,al ; Save it not al ; Reverse all bits out dx,al ; Stick it back jmp SHORT $+2 ; Short delay jmp SHORT $+2 ; And another in al,dx ; Read the register again not al ; Reverse all bits jmp SHORT $+2 ; Short delay jmp SHORT $+2 ; And another out dx,al ; Put it back sti ; Interrupts back on cmp al,ah ; Same? ret ENDP TestForCRTC ; Serial port command handler -------------------------------------------------- ; The functions here are simple - program the specified serial port with the ; specified line communication parameters (baud rate, parity, data bits, and ; stop bits). PROC DoMode_Com near xor bx,bx mov es,bx ; Address BIOS data area mov bx,[WORD Com_Port] ; Get port number shl bx,1 ; Double for word sized I/O addresses mov dx,[es:bx+400h] ; Get I/O address of specified port test dx,dx ; Does the port exist? point bx,NoSuchSPortEM ; Prepare for no jz Com_Error ; If it doesn't exist, abort with error push dx ; Keep base pointer add dx,3 ; Point to LCR mov al,10000000b ; Set DLAB (divisor latch access bit) out dx,al ; Set the LCR value pop dx ; Point back to lobyte of divisor mov ax,[Com_BRD] ; Get baud rate divisor out dx,al ; Set the lobyte inc dx ; Point to hibyte mov al,ah ; Get hibyte out dx,al ; Set the hibyte inc dx inc dx ; Point to the LCR again mov al,[Com_LCR] ; Get specified LCR value out dx,al ; Set it point dx,SerialSetMsg ; Message jmp MessageExit0 ; Issue message and terminate Com_Error: jmp ErrExit ; Go to error exit handler ENDP DoMode_Com ; Parallel port command handler ------------------------------------------------ ; There are four parallel port commands - the LPTn:P command which specifies ; persistent behaviour, i.e. infinite timeout, on the specified parallel port, ; the LPTn:=COMx command, which redirects output from the specified parallel ; port to the specified serial port, the LPTn:=NUL command, which redirects ; output from the specified parallel port to nowhere, and the LPTn: command ; which removes the infinite timeout (if active) and the parallel port ; redirection (if active) for the specified parallel port. ; Note - the specified parallel port may be LPT1 through LPT4, and MODE does ; not ensure that the port physically exists. This allows (for example) LPT2 ; to be redirected to a serial port when only LPT1 is present, giving an ; "extra" addressable port. However, if a parallel port is redirected to a ; serial port, MODE does check that the serial port exists. Here is the ; behaviour table: ; ; Func Inst? Hook? Action Message ; ; Norm N N/A None Port set to normal ; Norm Y N Set param in resident copy Port set to normal ; Norm Y Y Set param in resident copy Port set to normal ; Pers N N/A Hook this copy, go resident Port state, resident ; Pers Y N Hook resident copy, set param Port state ; Pers Y Y Set param in resident copy Port state ; Redr N N/A Hook this copy, go resident Port state, resident ; Redr Y N Hook resident copy, set param Port state, resident ; Redr Y Y Set param in resident copy Port state, resident ; ; Notes: ; ; Some of the messages are a bit misleading; this is due to the great number ; of possible combinations of installed/not installed, hooked/not hooked, ; existing port mode, new port mode, and command specified. For example, if ; MODE is not installed, or if the installed copy is not hooked into the ; printer function interrupt, and the LPTn: command (return to normal) is ; issued, MODE says that the port has been set for normal operation, even ; though it was never set to anything else. Also, if the mode is changed ; with any of the three command types, MODE does not take notice of the ; previous mode. Thus if you entered MODE LPT1:P twice, it would say the ; same thing both times - that the port is now configured for persistent ; retries - even though the second time it was already configured for ; persistent retries before MODE was invoked. ; ; Redirection to NUL is faked as redirection to COM7. PROC DoMode_LPT near mov bx,[WORD LPT_Port] ; Get port number push ds pop es ; Will address vars with ES cmp [Already],0 ; Is there an installed copy? jz NotInst ; If not mov es,[Already] ; Get resident copy ; Check for set-normal command NotInst: cmp [LPT_Func],0 ; Check for set-to-normal command jnz NotSetNormal ; If not mov [es:LPT_Ctrl+bx],0 ; Remove special settings add [SetNormalLPT],bl ; Set appropriate port number point dx,SetNormalMsg ; Message GoMsgExit0: jmp MessageExit0 ; Exit with message, errorlevel zero ; Was not LPTn: command - must be LPTn:P or LPTn:=COMx/NUL. If it's the ; latter, now check that the specified serial port (to be redirected to) ; exists. Treat a port value of 7 specially - it indicates redirection to ; NUL. NotSetNormal: js NoCheckRedir ; If redirect command mov bx,[WORD LPT_Func] ; Get serial port to redirect _to_ cmp bl,7 ; Is it COM7? je NoCheckRedir ; If so, don't check! shl bx,1 ; Double for word sized I/O addresses xor ax,ax mov ds,ax ; Address BIOS data area with DS ASSUME ds:nothing mov dx,[ds:bx+3FEh] ; Get I/O address of serial port push cs pop ds ; DS back to normal ASSUME ds:ComFile test dx,dx ; Does the port exist? point bx,NoSuchSPortEM ; Prepare for no jz Com_Error ; If it doesn't exist, abort with error ; Was not LPTn: command - must be LPTn:P or LPTn:=COMx/NUL. For these ; commands, MODE must either already _be_ resident, or must _go_ resident. ; Check for installed copy and address either this copy, or the resident copy. ; Have ES pointing either to local segment, or to installed copy (if there ; is an installed copy). NoCheckRedir: mov ax,[es:Old17Ofs] ; Get offset of chain vector or ax,[es:Old17Seg] ; Has vector been hooked? jnz WasHooked ; If so ; Either this copy (which will go resident), or the resident copy, did not have ; int 17h hooked - so hook it now. push es pop ds ASSUME ds:nothing ; DS now addresses whichever copy mov ax,3517h int 21h ; Get int 17h vector mov [ds:Old17Ofs],bx mov [ds:Old17Seg],es ; Store it point dx,New17 mov ax,2517h int 21h ; Set new vector push ds pop es ; ES back to this or resident copy push cs pop ds ASSUME ds:ComFile ; DS back to normal ; Either this copy, or the resident copy, is hooked in to int 17h and needs ; to have the appropriate parallel port parameter set. ES addresses whichever ; copy is or will be installed. WasHooked: mov bx,[WORD LPT_Port] ; Get port number again mov al,[LPT_Func] ; Get command again test al,10000000b ; Redirect or persistent? js SetPersist ; If persistent and [es:LPT_Ctrl+bx],11111000b ; Mask off old redirection SetPersist: or [es:LPT_Ctrl+bx],al ; Set new redirection or persistent ; Issue the appropriate message - either port set for infinite timeout or ; port redirected mov al,[LPT_Func] ; Get function test al,al ; Which is it? point dx,SetPersistMsg ; Prepare for set to persistent js GotPersRedir ; If so cmp al,7 ; Check for redirection to NUL point dx,SetRedNULMsg ; Prepare for it je GotPersRedir ; If it was point dx,SetRedirMsg ; Set to redirected add [SetRedirCOM],al ; Set serial port number in message ; Now have message, so do we need to install or not? GotPersRedir: cmp [Already],0 ; Already installed? jnz GoMsgExit0 ; If so, just issue the message mov ah,9 int 21h ; Display message point dx,ResInstallMsg ; Inform user MODE is now resident jmp MessageTSR0 ; Issue message and TSR ENDP DoMode_LPT ; Park command handler --------------------------------------------------------- ; The park command is either immediate (i.e. no minutes:seconds value provided) ; or a timed park. First, check that at least one hard disk is present. If ; the park is immediate, just park the hard drives and issue a message then ; wait for a reboot, etc. In the second case, we either go resident with the ; timer and disk function interrupts hooked, or update the timed park parameter ; in the resident copy. PROC DoMode_Park near mov dl,80h ; Test first hard disk for Ready mov ah,10h int 13h point bx,NoHDiskEM ; Prepare for error jnc HaveHDisk ; If alright jmp ErrExit ; If no hard disk present! HaveHDisk: mov ax,[Park_Ticks] ; Get number of ticks specified test ax,ax ; Any park time specified? jnz TimedPark ; If so ; Immediate park was requested - ignore any resident copy, if present. Get ; end cylinder for drive 0 and park it, check for existence of a second drive ; and if it exists, do the same mov ah,8 ; Get drive parameters function int 13h ; Do it mov dl,80h ; Reinstate drive number mov ah,0Ch ; Seek function int 13h ; Do it point si,Parked1Msg ; Prepare for only one hard disk parked inc dx ; Test second hard disk for Ready mov ah,10h int 13h jc NoDisk1 ; If no second hard disk mov ah,8 ; Get drive parameters function int 13h ; Do it mov dl,80h ; Reinstate drive number mov ah,0Ch ; Seek function int 13h ; Do it point si,Parked2Msg ; Two hard drives were parked ; Display informative message and wait NoDisk1: mov dx,si ; Get message mov ah,9 ; Display message function int 21h ; Call DOS ParkLoop: mov ah,8 ; Keyboard input, no echo, break active int 21h ; Call DOS jmp SHORT ParkLoop ; Forever ; Timed park function has been requested - check whether a resident copy is ; present. If not, initialise the timeout counters in this copy, store the ; drive parameters, and go resident with the appropriate message. If there ; is a resident copy present, update the resident parameters, including ; resetting the two actual timeout counters, and check whether the resident ; copy has its timed park function active. This is true if the int 13h chain ; vector in the resident copy is nonzero. If so, exit with the message that ; the resident parameters have been modified. If not, determine the drive ; parameters and set them in the resident copy, hook the vectors into the ; resident copy and exit with the message that the timed park function has ; now been enabled in the resident copy. TimedPark: cmp [Already],0 ; Already have a resident copy? jnz WasAlready4 ; If so ; Timed park was requested and there is no resident copy - set some parameters ; and go resident mov [ParkDrive0],ax ; Initialise timeout mov [ParkDrive1],ax ; for both drives mov ah,8 ; Get drive parameters function int 13h ; Do it mov [MaxCylinder0],cx ; Store number of last cylinder point si,ParkInst1Msg ; Prepare for only one hard disk found mov dl,81h ; Test second hard disk for Ready mov ah,10h int 13h jc NoDisk2 ; If no second hard disk mov ah,8 ; Get drive parameters function int 13h ; Do it mov [MaxCylinder1],cx ; Store number of last cylinder point si,ParkInst2Msg ; Point to message for two drives ; Hook interrupts 8 and 13h NoDisk2: mov ax,3508h int 21h ; Get int 8 vector mov [Old08Ofs],bx mov [Old08Seg],es ; Store it point dx,New08 mov ax,2508h int 21h ; Set new vector mov ax,3513h int 21h ; Get int 13h vector mov [Old13Ofs],bx mov [Old13Seg],es ; Store it point dx,New13 mov ax,2513h int 21h ; Set new vector mov dx,si ; Appropriate message to DX jmp MessageTSR0 ; Issue message and go resident ; A resident copy exists WasAlready4: mov es,[Already] ; Get segment of installed copy mov [es:Park_Ticks],ax ; Update resident timeout parameter mov [es:ParkDrive0],ax ; Reset resident timeout counter mov [es:ParkDrive1],ax ; for both drives mov ax,[es:Old13Ofs] ; Get chain vector offset or ax,[es:Old13Seg] ; Check whether park function active jz ParkWasNot ; If not point dx,ParkResMsg ; If so, resident parameter modified jmp MessageExit0 ; Display message and terminate ; An installed copy is present but it does not have its park function enabled ParkWasNot: mov ah,8 ; Get drive parameters function int 13h ; Do it mov [es:MaxCylinder0],cx ; Store number of last cylinder point si,ParkEnab1Msg ; Prepare for only one hard disk found mov dl,81h ; Test second hard disk for Ready mov ah,10h int 13h jc NoDisk3 ; If no second hard disk mov ah,8 ; Get drive parameters function int 13h ; Do it mov [MaxCylinder1],cx ; Store number of last cylinder point si,ParkEnab2Msg ; Point to message for two drives ; Hook interrupts 8 and 13h to resident copy NoDisk3: push es pop ds ; Set DS to resident copy ASSUME ds:nothing mov ax,3508h int 21h ; Get int 8 vector mov [ds:Old08Ofs],bx mov [ds:Old08Seg],es ; Store it point dx,New08 mov ax,2508h int 21h ; Set new vector mov ax,3513h int 21h ; Get int 13h vector mov [ds:Old13Ofs],bx mov [ds:Old13Seg],es ; Store it point dx,New13 mov ax,2513h int 21h ; Set new vector push cs pop ds ; DS back to local segment ASSUME ds:ComFile mov dx,si ; Appropriate message to DX jmp MessageExit0 ; Issue message and exit ENDP DoMode_Park ; Typematic command handler ---------------------------------------------------- ; Typematic parameters were specified. First, check that both delay and rate ; were given - both are required. Then check whether a resident copy exists, ; and if so, copy the typematic settings into the resident copy, and check ; whether the resident copy has its typematic lock function enabled (this is ; true if the chain vector for int 16 in the resident copy is nonzero). Also ; check the lock flag in the transient copy. Behave according to the following ; table: ; ; Res? Locked? LOCK? Action Message(s) ; ; N N/A N Call BIOS Set ; N N/A Y Hook, go resident Locked, installed ; Y N N Update TSR, call BIOS Set ; Y N Y Update TSR, hook to resident Locked parms set ; Y Y N/A Update TSR, call BIOS Locked parms set PROC DoMode_Typematic near point bx,TypeParamEM ; Prepare for parameter error mov ax,[Type_Parm] ; Get delay and rate cmp ah,0FFh ; Make sure a delay was entered je Type_Error ; If not cmp al,0FFh ; Make sure a rate was entered jne TypeParamsOK ; If alright Type_Error: jmp ErrExit ; Go to error exit handler TypeParamsOK: cmp [Already],0 ; Are we already installed? jnz WasAlready5 ; If so ; Not resident - if no lock flag, just call the BIOS function and exit with ; the message 'typematic parameters set'. If lock flag is set, hook int 16h ; into transient copy and go resident, with an appropriate message. cmp [Type_Lock],0 ; Lock specified? jnz Type_IsLock ; If so TypeSet: point dx,TypeSetMsg ; Message jmp SetTypeExit ; Call BIOS, display message, and exit ; Was not resident but lock was specified - hook vector and go resident Type_IsLock: mov ax,3516h int 21h ; Get int 16h vector mov [Old16Ofs],bx mov [Old16Seg],es ; Store it point dx,New16 mov ax,2516h int 21h ; Set new vector mov ax,305h ; Function to set typematic int 16h ; Set it - no parameter needed ; because lock code is resident point dx,LockInstMsg ; Message ; Entry point for use by other handlers - at this point, DX points to the ; message to be issued. The message will be sent via DOS function 9, and ; the program will hook int 2Fh (TSR locate vector), deallocate its copy of ; the environment, and terminate and stay resident with errorlevel zero. MessageTSR0: mov ah,9 int 21h ; Display message TSR0: mov ax,352Fh int 21h ; Get int 2Fh vector mov [Old2FOfs],bx mov [Old2FSeg],es ; Store it point dx,New2F mov ax,252Fh int 21h ; Set new vector mov es,[ComFile:2Ch] ; Get segment of environment block mov ah,49h ; Free memory block function int 21h ; Deallocate our copy of environment mov dx,TSRParas ; Number of paragraphs to leave resident mov ax,3100h int 21h ; Go resident ; Resident copy was found - update resident typematic parameters, see whether ; resident copy has typematic lock enabled and whether lock was requested then ; behave according to above table. WasAlready5: mov es,[Already] ; Get resident segment mov [WORD es:Type_Parm],ax ; Update resident values mov ax,[es:Old16Ofs] ; Get old int 16h vector offset or ax,[es:Old16Seg] ; Is resident copy in locked mode? jnz Res_Locked ; If so ; Resident copy is not locked - did user specify locking? cmp [Type_Lock],0 ; Lock requested? jz TypeSet ; If not, just set typematic and exit ; Resident copy is not locked but user specified locking push es pop ds ; DS to resident copy ASSUME ds:nothing mov ax,3516h int 21h ; Get int 16h vector mov [ds:Old16Ofs],bx mov [ds:Old16Seg],es ; Store it in resident copy point dx,New16 mov ax,2516h int 21h ; Set new vector push cs pop ds ; Restore to transient copy ASSUME ds:ComFile point dx,ResLockedMsg ; Message jmp SHORT SetTypeExit ; Resident copy was locked Res_Locked: point dx,TResUpdateMsg ; Resident locked parameters updated ; At this point - DX points to the message to be displayed. Get the typematic ; parameters and call the BIOS (this may actually set typematic, or may just ; cause the locked parameters to be set, depending on whether there is a ; hooked copy of MODE), then display the specified message and terminate ; with errorlevel zero. SetTypeExit: mov bx,[Type_Parm] ; Parameters to BX mov ax,305h ; Function to set typematic int 16h ; Set it ; Entry point for use by other handlers - at this point, DX points to the ; message to be issued. The message will be sent via DOS function 9, and ; the program will terminate and return to DOS with errorlevel zero. MessageExit0: mov ah,9 ; Display message int 21h Exit0: mov ax,4C00h ; Terminate with errorlevel zero int 21h ENDP DoMode_Typematic ; Working stack area ----------------------------------------------------------- ALIGN 2 WorkStack DB 512 DUP(?) ; Working stack WorkStackTop = $ ; End of transient portion ----------------------------------------------------- MASM FreeSpace = $ MemParas = (OFFSET (FreeSpace-@curseg+15) SHR 4) prexp <Transient size:> %(MemParas SHL 4) < bytes> IDEAL ENDS ComFile END Main ;-------------------------------------------------------------------------------