Piper's Pit BBS/FTP: ibm 0000

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Assembly Source File | 1989-07-10 | 42.0 KB | 1,596 lines

;****************************************************** ; TPCRT.ASM 5.07 ; Low level CRT routines ; Copyright (c) TurboPower Software 1987. ; Portions copyright (c) Sunny Hill Software 1985, 1986 ; and used under license to TurboPower Software ; All rights reserved. ;****************************************************** INCLUDE TPCOMMON.ASM ;****************************************************** Equates ;structure of a Turbo FIB (File Interface Block) FHandle EQU (WORD PTR 0) FMode EQU (WORD PTR 2) FBufSize EQU (WORD PTR 4) FPrivate EQU (WORD PTR 6) FBufPos EQU (WORD PTR 8) FBufEnd EQU (WORD PTR 10) FBufPtr EQU (DWORD PTR 12) FOpenProc EQU (DWORD PTR 16) FInOutProc EQU (DWORD PTR 20) FFlushProc EQU (DWORD PTR 24) FCloseProc EQU (DWORD PTR 28) FUserData EQU (BYTE PTR 32) FName EQU (BYTE PTR 48) FBuffer EQU (BYTE PTR 128) ;FMode constants FMClosed = 0D7B0h FMInput = 0D7B1h FMOutput = 0D7B2h FMInOut = 0D7B3h ;equates for referencing pointers to FIB's on the stack TextFile EQU DWORD PTR SS:[BX+4] TextFileBP EQU [BP+6] TFPtr EQU ES:[DI] ;keys / control characters Null = 0 CtrlA = 1 CtrlC = 3 CtrlD = 4 CtrlF = 6 Bell = 7 BkSp = 8 LineFeed = 10 Return = 13 CR = 13 CtrlR = 18 CtrlS = 19 CtrlX = 24 CtrlZ = 26 Escape = 27 CtrlBkSp = 127 ;****************************************************** Macros Write MACRO Char MOV AL, Char ;Al has character to write CALL WriteChar ;Write it ENDM WriteLn MACRO Write CR ;Write the carriage return Write LineFeed ;Write the line feed ENDM ;****************************************************** Data DATA SEGMENT BYTE PUBLIC ;Pascal variables EXTRN CheckBreak : BYTE ;Check for ^Break? EXTRN CheckEof : BYTE ;Check for ^Z on Read/Ln? EXTRN DirectVideo : BYTE ;If false, use BIOS EXTRN WindMin : WORD ;Min. XY coordinates EXTRN WindMax : WORD ;Max. XY coordinates EXTRN LastMode : WORD ;Current video mode EXTRN CurrentMode : BYTE ;Current video mode EXTRN CurrentPage : BYTE ;Current video page EXTRN ScreenWidth : BYTE ;Current width of display EXTRN VirtualWidth : BYTE ;Current width of virtual display EXTRN ScreenHeight : BYTE ;Current height of display EXTRN CurrentHeight : BYTE ;Current height of display-1 EXTRN CurrentDisplay : BYTE ;Current display type EXTRN EnhancedDisplay : BYTE ;Type of enhanced display ;installed, if any EXTRN WhichHerc : BYTE ;Type of Herc card installed EXTRN InTextMode : BYTE ;False if in graphics mode EXTRN TextAttr : BYTE ;Current video attribute EXTRN TextChar : BYTE ;background character EXTRN NormalAttr : BYTE; ;Attribute for NormVideo EXTRN CheckSnow : BYTE ;If true, check for retrace EXTRN CtrlBreakFlag : BYTE ;True if ^Break pressed EXTRN VideoSegment : WORD ;Segment of Video Memory EXTRN VirtualSegment : WORD ;Segment of Video Memory--alt EXTRN BufLen : WORD ;Max length of string for Read EXTRN ExitProc : DWORD ;Turbo's ExitProc pointer EXTRN Save1B : DWORD ;Previous INT 1Bh handler EXTRN DetectMultitasking : BYTE ;If True, automatically checks ; for multitasker EXTRN MultitaskingOn : BYTE ;True if running under ; multitasker EXTRN IsCompaq : BYTE ;True if system is a COMPAQ EXTRN BiosScroll : BYTE ;If False, use special scroll ; routine EXTRN DisplayOverride : BYTE ;override auto-detection EXTRN NextChar : BYTE ;Used by KeyPressed/ReadKey EXTRN OneMS : WORD ;Loop count for 1 ms delay EXTRN SaveExitProc :DWORD ;Saves old ExitProc DATA ENDS ;****************************************************** Code CODE SEGMENT BYTE PUBLIC ASSUME CS:CODE, DS:DATA ;Pascal routines EXTRN WhichHercCard : NEAR ;Herc detection routine ;standard CRT unit routines PUBLIC ReadKey, InitCrt, AssignCrt ;extensions PUBLIC ReInitCrt ;low-level routines PUBLIC ReadCursorPrim, SetCursorPrim, GetCursorPrim, GetCrtModePrim PUBLIC ScrollUpPrim, ScrollDownPrim, AdapterCheck, DelayMS PUBLIC GetCharAttr, SetWindowPrim, FullWindow, GetAttribute ;data in code segment OurDS DW DATA ;Init'd by EXE loader to value of DS AdapterTable1 LABEL BYTE DB UnknownD ;0 = no display DB Mono ;1 = mono DB CGA ;2 = CGA DB UnknownD ;3 = reserved DB EGA ;4 = EGA w/color DB EGA ;5 = EGA w/mono DB PGC ;6 = Professional Graphics controller DB VGA ;7 = VGA w/mono DB VGA ;8 = VGA w/color DB UnknownD ;9 = reserved DB MCGA ;A = MCGA w/digital color DB MCGA ;B = MCGA w/mono DB MCGA ;C = MCGA w/analog color AdapterTable2 LABEL BYTE DB Unenhanced ;0 = not enhanced DB Unenhanced ;1 = " DB Unenhanced ;2 = " DB Unenhanced ;3 = " DB EGA ;4 = EGA w/color DB EGA ;5 = EGA w/mono DB PGC ;6 = Professional Graphics controller DB VGA ;7 = VGA w/mono DB VGA ;8 = VGA w/color DB Unenhanced ;9 = not enhanced DB MCGA ;A = MCGA w/digital color DB MCGA ;B = MCGA w/mono DB MCGA ;C = MCGA w/analog color ;****************************************************** AdapterCheck JunkValue = 0FFFFh AdapterCheck PROC NEAR MOV WP ScreenHeight,25 ;Assume 25-line mode MOV WP CurrentHeight,24 AND WP LastMode,00FFh ;Clear high byte of LastMode MOV AL,DisplayOverride ;check for override CMP AL,-1 ;-1 means no override JE ACauto ;if -1, use auto detect CMP AL,VGA ;is it in Mono..VGA? JA ACauto ;if not, use auto detect MOV CurrentDisplay,AL ;use the override MOV EnhancedDisplay,AL CMP AL,MCGA ;is MCGA or higher indicated? JAE ACgetheight ;if so, check height MOV EnhancedDisplay,0 ;not enhanced MOV CurrentDisplay,CGA ;assume CGA CMP CurrentMode,7 ;Current mode = 7? JNE ACexit1 ;if not, done MOV CurrentDisplay,Mono ;else, mono ACexit1: RET ;done ACgetHeight: JMP SHORT ACheight ;test for VGA, MCGA ACauto: VidCallAX 1A00h ;Video display combination CMP AL,1Ah ;AL = $1A signals valid call JNE ACega ;Check for EGA if invalid ;get current display type MOV DX,BX ;move result from BX into DX CMP DL,0Ch ;DL should be in range 1..C JA ACega MOV AL,DL ;translate into our terms MOV BX,Offset AdapterTable1 XLAT BYTE PTR CS:[0] CMP AL,UnknownD ;check for unknown adapter JE ACega ;use EGA test after all MOV CurrentDisplay,AL ;save result ;get enhanced display type MOV AL,DL ;assume one display OR DH,DH ;DH of 0 means one display JZ ACone CMP DH,0Ch ;else DH should be in range 1..C JA ACone CMP DH,DL ;if two, enhanced has higher value JB ACone MOV AL,DH ACone: MOV BX,Offset AdapterTable2 XLAT BYTE PTR CS:[0] MOV EnhancedDisplay,AL ;save result JMP SHORT ACHeight ;Check the height ;test for EGA ACega: MOV CurrentDisplay,EGA ;Assume EGA MOV EnhancedDisplay,EGA MOV BX,0FF10h ;Return EGA information MOV CX,JunkValue ;Load CX with junk value VidCallAX 1200h ;Alternate function select SetZero AL ;AL = 0 CMP CX,JunkValue ;CX unchanged? JE ACnotEnhanced ;If so, not an enhanced display CMP BH,1 ;BH should be 0 or 1 JA ACnotEnhanced ;Mono or CGA if it isn't ;See if EGA/VGA is the active monitor CMP BH,1 ;mono display? JE ACMono ;If so, use mono check CMP CurrentMode,7 ;In mono mode? JE ACPlain ;If so, we're not on the EGA/VGA/MCGA JMP SHORT ACHeight ;Else check height ACMono: CMP CurrentMode,7 ;Current mode = 7? JNE ACPlain ;Exit if not ;check the height of the display ACHeight: MOV CX,40h ;CX = $40 MOV ES,CX ;ES = $40 MOV CL,ES:[84h] ;CL = Number of rows - 1 MOV CurrentHeight,CL ;Set CurrentHeight and ScreenHeight INC CL MOV ScreenHeight,CL CMP CL,25 ;Is it 25-line mode? JE ACexit ;If so, done OR WP LastMode,Font8x8 ;Set Font8x8 bit CMP CL,43 ;Is it 43-line mode? JE ACexit ;if so, done CMP CL,50 ;Is it 50-line mode? JE ACexit ;if so, done AND WP LastMode,00FFh ;Clear Font8x8 bit of LastMode ACexit: RET ACnotEnhanced: MOV EnhancedDisplay,0 ;No enhanced display installed ACPlain: CMP CurrentDisplay,EGA ;Set to EGA? JNE ACExit ;Exit if not MOV CurrentDisplay,CGA ;Assume CGA CMP CurrentMode,7 ;Mono mode JNE ACExit ;Done if not MOV CurrentDisplay,Mono ;Else, Mono RET AdapterCheck ENDP ;****************************************************** BreakCheck ;Check for ^Break BreakCheck PROC NEAR CMP CtrlBreakFlag,False ;Break flag set? JE BreakExit ;Done if not MOV CtrlBreakFlag,False ;Reset break flag FlushKbdBuffer: KbdCall 1 ;Key pressed function JZ BreakCtrlC ;If no keypress, continue KbdCall 0 ;Read next character JMP SHORT FlushKbdBuffer ;Repeat BreakCtrlC: Write '^' ;Write the caret Write 'C' ;Write the 'C' WriteLn ;Write a CR/LF INT 23h ;Abort BreakExit: RET BreakCheck ENDP ;****************************************************** ReadKey ;function ReadKey : Char; ;Read a character from the keyboard ReadKey PROC FAR MOV AL,NextChar ;AL = NextChar MOV NextChar,0 ;NextChar = 0 OR AL,AL ;See if NextChar = 0 JNZ ReadKeyExit ;If not, we're done ReadKeyStart: INT 28h ;Help keep popups from locking out ;other TSR's KbdCall 1 ;Key pressed function JZ ReadKeyStart ;If no keypress, loop KbdCall 0 ;Read next char service OR AL,AL ;Check for AL = 0 JNZ ReadKeyExit ;Exit if AL <> 0 MOV NextChar,AH ;Save extended scan code OR AH,AH ;Check for scan code of 0 (^Break) JNZ ReadKeyExit ;Exit if AH <> 0 MOV AL,CtrlC ;Else, AL = ^C ReadKeyExit: CALL BreakCheck ;Check for break if necessary RET ReadKey ENDP ;****************************************************** SetCursorPrim ;Primitive routine to set cursor coordinates ;On entry, DH has row (Y), DL has column (X) SetCursorPrim PROC NEAR CMP DirectVideo,False ;Direct video flag on? JE SCNotDirect ;If not, use BIOS call CMP MultitaskingOn,True ;Multitasking flag on? JE SCNotDirect ;If so, use BIOS call ;Set cursor position in BIOS data area MOV BX,0040h ;BX = $40 MOV ES,BX ;ES = $40 MOV BL,CurrentPage ;BL = CurrentPage, BH = 0 SHL BX,1 ;Multiply by 2 MOV ES:50h[BX],DX ;DX has cursor position ;program the 6845 SetZero AH MOV AL,DH ;AL = Row MUL ScreenWidth ;AX = Row * width of screen SetZero DH ;DX = Column (in DL, DH is 0) ADD AX,DX ;AX = (Row * width) + Column SHL AX,1 ;Multiply by 2 ADD AX,ES:[4Eh] ;DX has starting offset of video memory SHR AX,1 ;Divide by 2 MOV BX,AX ;BX = (Row * width) + Column MOV DX,ES:[63h] ;DX has address of 6845 ($03D4/$03B4) MOV AL,14 ;Select cursor address (high) register OUT DX,AL ;Write the byte NullJump ;Wait MOV AL,BH ;Get high byte of word INC DX ;Next register ($03D5/$03B5) OUT DX,AL ;Write the byte NullJump ;Wait DEC DX ;Previous register ($03D4/$03B4) MOV AL,15 ;Select cursor address (low) register OUT DX,AL ;Write the byte NullJump ;Wait MOV AL,BL ;Get low byte of word INC DX ;Next register ($03D5/$03B5) OUT DX,AL ;Write the byte NullJump ;Wait RET SCNotDirect: ;Set cursor position with BIOS call MOV BH,CurrentPage ;BH = current display page VideoCall 2 ;Set cursor service RET SetCursorPrim ENDP ;****************************************************** GetCursorPrim ;Primitive routine to get cursor coordinates ;On exit, DH has row, DL has column, CH has starting scan line, CL has ending GetCursorPrim PROC NEAR CMP DirectVideo,False ;Direct video flag on? JE GCNotDirect ;If not, use BIOS call CMP MultitaskingOn,True ;Multitasking flag on? JE GCNotDirect ;If so, use BIOS call ;get cursor position from BIOS data area MOV BX,0040h ;BX = $40 MOV ES,BX ;ES = $40 MOV BL,CurrentPage ;BL = CurrentPage, BH = 0 SHL BX,1 ;Multiply by 2 MOV DX,ES:50h[BX] ;DX has cursor position for CurrentPage MOV CX,ES:60h ;CX has cursor shape RET GCNotDirect: ;get cursor position with BIOS call MOV BH,CurrentPage ;BH = current display page VideoCall 3 ;Read cursor service RET GetCursorPrim ENDP ;****************************************************** ReadCursorPrim ;Primitive routine to get cursor size and position ;On exit, DH has row, DL has column, AH has starting scan line, AL has ending ReadCursorPrim PROC NEAR CALL GetCursorPrim MOV AX,CX ;Scan lines from CX into AX RET ReadCursorPrim ENDP ;****************************************************** DelayMS ;Delay one millisecond DelayMS PROC NEAR CMP AL,ES:[DI] JNE DMSexit LOOP DelayMS DMSexit: RET DelayMS ENDP ;****************************************************** CrtExitProc ;Invoked when a program is ending. Restore INT 1B vector. CrtExitProc PROC FAR GetPtr SaveExitProc ;ES:DI points to old ExitProc SetPtr ExitProc, ES, DI ;Restore old ExitProc MOV CtrlBreakFlag,False ;Reset CtrlBreakFlag PUSH DS ;Save DS LDS DX,Save1B ;DS:DX has saved vector MOV AX,251Bh ;AH = Set interrupt vector service ;AL = interrupt vector INT 21h ;Call DOS POP DS ;Restore DS RET CrtExitProc ENDP ;****************************************************** Int1B ;Handles INT 1Bh, ^Break interrupt Int1B PROC NEAR PUSH DS ;Save DS PUSH AX ;Save AX MOV DS,CS:OurDS ;Restore our DS MOV AL,CheckBreak ;If CheckBreak is True... MOV CtrlBreakFlag,AL ;CtrlBreakFlag will be True also POP AX ;Restore AX POP DS ;Restore DS IRET Int1B ENDP ;****************************************************** GetCharAttr ;Get current character and attribute ;Returns attribute in AH, character in AL GetCharAttr PROC NEAR MOV BH,CurrentPage ;BH = current video page VideoCall 8 ;Read char and attribute service RET GetCharAttr ENDP ;****************************************************** GetAttribute ;Get current attribute at cursor GetAttribute PROC NEAR CALL GetCharAttr ;Get char and attribute AND AH,01111111b ;Mask out the blink bit MOV TextAttr,AH ;Attribute at cursor is in AH MOV NormalAttr,AH ;Attribute for NormVideo RET GetAttribute ENDP ;****************************************************** GetCrtModePrim ;Return the current video mode in AL, initialize most global screen variables GetCrtModePrim PROC NEAR VideoCall 0Fh ;Get video mode service AND AL,7Fh ;mask out high bit, sometimes set on EGA MOV CurrentMode,AL ;Save video mode MOV ScreenWidth,AH ;Save width MOV VirtualWidth,AH MOV CurrentPage,BH ;Save page MOV InTextMode,True ;Assume text mode SetZero DX ;DX = 0 MOV CX,0B000h ;Assume mono card CMP AL,7 ;In monochrome mode? JE GetCrtExit ;If so, exit ;get the segment of video memory for the current page MOV CX,40h ;CX = $40 MOV ES,CX ;ES = $40 MOV CX,ES:[4Eh] ;CX = MemW[$40:$4E] SHR CX,1 ;Convert offset to paragraph SHR CX,1 SHR CX,1 SHR CX,1 ADD CX,0B800h ;Color card ;make sure we're not in graphics mode CMP AL,3 ;In mode 0-3? JNA GetCrtExit ;If so, in text mode MOV InTextMode,False ;Else, graphics mode GetCrtExit: MOV VideoSegment,CX ;Save video segment MOV VirtualSegment,CX CMP DetectMultitasking,True ;Check for multitasker? JE GCcheck ;If so, do the check MOV MultitaskingOn,False ;Else, turn the flag off RET ;check for multitasker GCcheck: MOV ES,CX ;Put video segment in ES SetZero DI ;DI = 0 PUSH BP ;Save BP VidCallAX 0FE00h ;Get segment of virtual screen POP BP ;Restore BP SetZero AL ;AL = False MOV BX,ES ;Return value into BX CMP BX,VideoSegment ;Same as before? JE GCno ;If so, not multitasking MOV VideoSegment,BX ;Save segment MOV VirtualSegment,BX INC AL ;AL = True GCno: MOV MultitaskingOn,AL ;Save multitasking flag MOV AL,CurrentMode ;Return current mode in AL RET GetCrtModePrim ENDP ;****************************************************** SetWindowPrim ;Primitive routine to set current window coordinates ;On entry, the new Y coordinates must be in CX, X coordinates in DX SetWindowPrim PROC NEAR MOV WindMin.XLow,DL ;Set XLow MOV WindMax.XHigh,DH ;Set XHigh MOV WindMin.YLow,CL ;Set YLow MOV WindMax.YHigh,CH ;Set YHigh RET SetWindowPrim ENDP ;****************************************************** FullWindow ;Makes the entire screen the window FullWindow PROC NEAR SetZero DL ;XLow = 0 MOV CL,DL ;YLow = 0 MOV DH,ScreenWidth ;DH = ScreenWidth-1 DEC DH MOV CH,CurrentHeight ;CH = ScreenHeight-1 = CurrentHeight CALL SetWindowPrim ;Call primitive routine RET FullWindow ENDP ;****************************************************** ScrollUpPrim ;Primitive routine to scroll a window up, with optional snow/flicker prevention COMMENT | On entry: BH has the video attribute to use as filler CH has top row of window CL has left column DH has bottom row DL has right column AL has number of lines to scroll, AL = 0 means clear the whole window | SPcharsPerRow EQU BYTE PTR [BP-1] ;# of char/attr pairs per window row SProwsToMove EQU BYTE PTR [BP-2] ;# of rows to move SProwsToFill EQU BYTE PTR [BP-3] ;# of rows to fill SPattr EQU BYTE PTR [BP-4] ;attribute to fill with SPchar EQU BYTE PTR [BP-5] ;char to fill with ScrollUpPrim PROC NEAR CMP BiosScroll,False ;Use special scroll routine? JE SUspecial ;If not, use BIOS CMP TextChar,' ' ;Use ours if TextChar <> ' ' JNE SUspecial VideoCall 06h ;Scroll window up service RET SUspecial: CLD ;Go forward PUSH DS ;Save DS StackFrameBP SUB SP,5 ;Make room for locals MOV SPattr,BH ;Save attribute MOV AH,TextChar ;Save character MOV SPchar,AH MOV TextChar,' ' ;Reset TextChar ;Get rows in window into AH MOV AH,DH ;AH = bottom row SUB AH,CH ;AH = bottom row - top row INC AH ;AH = Succ(bottom row - top row) ;Get rows to scroll into AL CMP AL,AH ;AL > AH? JNA SUcheckZero ;If not, check for AL = 0 MOV AL,AH ;Else, AL = AH JMP SHORT SUnotWhole ;Continue SUcheckZero: OR AL,AL ;Is AL 0? JNZ SUnotWhole ;If not, use actual value MOV AL,AH ;Else, scroll entire window SUnotWhole: MOV SProwsToFill,AL ;Save # of rows to fill SUB AH,AL ;AH = # of rows to move MOV SProwsToMove,AH ;Save # of rows to move ;Get # of chars per row SetZero AH ;AH = 0 MOV AL,DL ;AL = right column SUB AL,CL ;AL = right column - left column INC AL ;AL = Succ(right column - left column) MOV SPcharsPerRow,AL ;Save # of char/attr pairs per row MOV SI,AX ;Save in SI too ;Get starting value for DI MOV BX,WP ScreenWidth ;BX = Chars per screen row MOV AL,CH ;AX = top row MUL BX ;AX = row * current width SetZero CH ;CH = 0, CX = LeftCol ADD AX,CX ;AX = (row * current width) + col SHL AX,1 ;account for attribute bytes MOV DI,AX ;DI has starting offset for top left ; corner of window SHL SI,1 ;SI = bytes per window row SHL BX,1 ;BX = Video words per screen row MOV CX,BX ;CX = Video words per screen row SUB BX,SI ;BX has delta to add when looping SetZero AH ;AH = 0 MOV AL,SProwsToFill ;AX = # of rows to fill MUL CX ;AX = rows to fill * words/screen row MOV SI,DI ;SI = DI ADD SI,AX ;Point SI to first row to move MOV AL,CheckSnow ;Grab this before changing DS MOV DX,VideoSegment ;DX = VideoSegment MOV ES,DX ;ES = VideoSegment MOV DS,DX ;DS = VideoSegment SetZero CH ;CH = 0 SHR AL,1 ;Snow checking on? JNC SUfullSpeed ;Skip next check if not CMP DH,0B8h ;See if we're moving/filling CGA memory JNE SUfullSpeed ;If not, don't wait for retrace ;Move screen data (with snow prevention) MOV DX,03DAh ;Point DX to CGA status port CMP SProwsToMove,0 ;Any rows to move? JE SUstartFillWait ;If not, start filling SUmoveWait: MOV CL,SPcharsPerRow ;CX = # of char/attr pairs to move WordMoveNoSnow ;Move CX words, preventing snow ADD DI,BX ;Point DI to next row ADD SI,BX ;Point SI to next row DEC SProwsToMove ;Decrement # of rows to move JNZ SUmoveWait ;If not zero, repeat ;Fill with blanks (with snow prevention) SUstartFillWait: MOV SI,BX ;Delta into SI MOV BH,SPattr ;Attribute into BH MOV BL,SPchar ;Filler into BL SUfillWait: MOV CL,SPcharsPerRow ;CX = # of char/attr pairs to fill SUfillNext: WaitForRetrace ;Wait for opportunity to write WordToCGA BX ;Move the word LOOP SUfillNext ;Fill next video word ADD DI,SI ;Point DI to next row DEC SProwsToFill ;Decrement # of rows to fill JNZ SUfillWait ;Repeat if not zero JMP SHORT SUExit ;All done ;Move screen data (no snow prevention) SUfullSpeed: MOV DL,SPcharsPerRow ;DL = # of char/attr pairs to move MOV DH,SProwsToMove ;DH = # of rows to move MOV AH,SPattr ;Attribute into AH MOV AL,SPchar ;Filler into AL OR DH,DH ;Any rows to move? JZ SUstartFillNoWait ;If not, start filling SUmoveNoWait: MOV CL,DL ;CX = # of char/attr pairs to move REP MOVSW ;Move 'em ADD DI,BX ;Point DI to next row ADD SI,BX ;Point SI to next row DEC DH ;Decrement # of rows to move JNZ SUmoveNoWait ;If not zero, repeat ;Fill with blanks (no snow prevention) SUstartFillNoWait: MOV DH,SProwsToFill ;DH = # of rows to fill SUfillNoWait: MOV CL,DL ;CX = # of char/attr pairs to move REP STOSW ;Fill this row ADD DI,BX ;Point DI to next row DEC DH ;Decrement # of rows to fill JNZ SUfillNoWait ;Repeat if not zero SUExit: MOV SP,BP ;Restore SP POP BP ;Restore BP POP DS ;Restore DS RET ;Return ScrollUpPrim ENDP ;****************************************************** ScrollDownPrim ;Primitive routine to scroll a window down, with optional snow/flicker prevention COMMENT | On entry: BH has the video attribute to use as filler CH has top row of window CL has left column DH has bottom row DL has right column AL has number of lines to scroll, AL = 0 means clear the whole window | ScrollDownPrim PROC NEAR CMP BiosScroll,False ;Use special scroll routine? JE SDspecial ;If not, use BIOS CMP TextChar,' ' ;Use ours if TextChar <> ' ' JNE SDspecial VideoCall 07h ;Scroll window down service RET SDspecial: CLD ;Go forward PUSH DS ;Save DS StackFrameBP SUB SP,5 ;Make room for locals MOV SPattr,BH ;Save attribute MOV AH,TextChar ;Save character MOV SPchar,AH MOV TextChar,' ' ;Reset TextChar ;Get rows in window into BL MOV BL,DH ;BL = bottom row SUB BL,CH ;BL = bottom row - top row INC BL ;BL = Succ(bottom row - top row) ;Get rows to scroll into AL CMP AL,BL ;AL > BL? JNA SDcheckZero ;If not, check for AL = 0 MOV AL,BL ;Else, AL = AH JMP SHORT SDnotWhole ;Continue SDcheckZero: OR AL,AL ;Is AL 0? JNZ SDnotWhole ;If not, use actual value MOV AL,BL ;Else, scroll entire window SDnotWhole: MOV SProwsToFill,AL ;Save # of rows to fill SUB BL,AL ;BL = # of rows to move MOV SProwsToMove,BL ;Save # of rows to move ;Get # of chars per row SetZero AH ;AH = 0 MOV AL,DL ;AL = right column SUB AL,CL ;AL = right column - left column INC AL ;AL = Succ(right column - left column) MOV SPcharsPerRow,AL ;Save # of char/attr pairs per row MOV SI,AX ;Save in SI too ;Get starting value for SI MOV AL,DH ;AX = bottom row MOV BX,WP ScreenWidth ;BX = Chars per screen row MUL BX ;AX = row * current width SetZero CH ;CH = 0, CX = LeftCol ADD AX,CX ;AX = (row * current width) + col SHL AX,1 ;account for attribute bytes MOV DI,AX ;SI has starting offset for last row SHL SI,1 ;SI = bytes per window row SHL BX,1 ;BX = Video words per screen row MOV CX,BX ;CX = Video words per screen row ADD BX,SI ;BX has delta to subtract when looping SetZero AH ;AH = 0 MOV AL,SProwsToFill ;AX = # of rows to fill MUL CX ;AX = rows to fill * words/screen row MOV SI,DI ;SI = DI SUB SI,AX ;Point SI to first row to move MOV AL,CheckSnow ;Grab this before changing DS MOV DX,VideoSegment ;DX = VideoSegment MOV ES,DX ;ES = VideoSegment MOV DS,DX ;DS = VideoSegment SetZero CH ;CH = 0 SHR AL,1 ;Snow checking on? JNC SDfullSpeed ;Skip next check if not CMP DH,0B8h ;See if we're moving/filling CGA memory JNE SDfullSpeed ;If not, don't wait for retrace ;Move screen data (with snow prevention) MOV DX,03DAh ;Point DX to CGA status port CMP SProwsToMove,0 ;Any rows to move? JE SDstartFillWait ;If not, start filling SDmoveWait: MOV CL,SPcharsPerRow ;CX = # of char/attr pairs to move WordMoveNoSnow ;Move CX words, preventing snow SUB DI,BX ;Point DI to previous row SUB SI,BX ;Point SI to previous row DEC SProwsToMove ;Decrement # of rows to move JNZ SDmoveWait ;If not zero, repeat ;Fill with blanks (with snow prevention) SDstartFillWait: MOV SI,BX ;Delta into SI MOV BH,SPattr ;Attribute into BH MOV BL,SPchar ;Filler into BL SDfillWait: MOV CL,SPcharsPerRow ;CX = # of char/attr pairs to fill SDfillNext: WaitForRetrace ;Wait for opportunity to write MOV AX,BX ;Get word back into AX STOSW ;Store the word STI ;Allow interrupts LOOP SDfillNext ;Fill next video word SUB DI,SI ;Point DI to previous row DEC SProwsToFill ;Decrement # of rows to fill JNZ SDfillWait ;Repeat if not zero JMP SHORT SDExit ;All done ;Move screen data (no snow prevention) SDfullSpeed: MOV DL,SPcharsPerRow ;DL = # of char/attr pairs to move MOV DH,SProwsToMove ;DH = # of rows to move MOV AH,SPattr ;Attribute into AH MOV AL,SPchar ;Filler into AL OR DH,DH ;Any rows to move? JZ SDstartFillNoWait ;If not, start filling SDmoveNoWait: MOV CL,DL ;CX = # of char/attr pairs to move REP MOVSW ;Move 'em SUB DI,BX ;Point DI to previous row SUB SI,BX ;Point SI to previous row DEC DH ;Decrement # of rows to move JNZ SDmoveNoWait ;If not zero, repeat ;Fill with blanks (no snow prevention) SDstartFillNoWait: MOV DH,SProwsToFill ;DH = # of rows to fill SDfillNoWait: MOV CL,DL ;CX = # of char/attr pairs to move REP STOSW ;Fill this row SUB DI,BX ;Point DI to previous row DEC DH ;Decrement # of rows to fill JNZ SDfillNoWait ;Repeat if not zero SDExit: MOV SP,BP ;Restore SP POP BP ;Restore BP POP DS ;Restore DS RET ;Return ScrollDownPrim ENDP ;****************************************************** CrtNop ;Do-nothing file handling procedure ;On entry, a pointer to a FileRec is on the stack CrtNop PROC FAR SetZero AX ;Signal AOK RET 4 CrtNop ENDP ;****************************************************** OutputChar ;On entry, AL has character to write OutputChar PROC NEAR PUSH DI ;Save DI MOV CL,AL ;CL has character MOV CH,TextAttr ;CH has TextAttr CMP DirectVideo,True ;Write directly to video memory? JNE BiosOutput ;If not, use BIOS CMP InTextMode,True ;In text mode? JNE BiosOutput ;If not, use BIOS CMP MultitaskingOn,True ;Multitasking? JNE OCgetCursor ;if not, don't need BIOS call ;get cursor position with BIOS call PUSH CX ;Save CX MOV BH,CurrentPage ;BH = current display page VideoCall 3 ;Read cursor service POP CX ;Restore CX JMP SHORT OCcalcAddress ;Ready to calculate address ;get cursor position from BIOS data area into DX OCgetCursor: MOV BX,0040h ;BX = $40 MOV ES,BX ;ES = $40 MOV BL,CurrentPage ;BL = CurrentPage, BH = 0 SHL BX,1 ;Multiply by 2 MOV DX,ES:50h[BX] ;DX has cursor position for CurrentPage ;calculate address in video memory OCcalcAddress: MOV AL,DH ;AL = row SetZero DH ;DH = 0 (DX = column) MUL ScreenWidth ;AL = (row * width) MOV DI,AX ;DI = (row * width) ADD DI,DX ;DI = (row * width) + column SHL DI,1 ;Account for attribute bytes MOV ES,VideoSegment ;ES has segment of video memory ;determine which method of output to use CMP CheckSnow,False ;Snow checking off? JE OutputStore ;If so, go ;Use the following only for color cards when retrace checking is on MOV DX,03DAh ;Point DX to CGA status port WaitForRetrace ;Wait for an opportunity to write OutputStore: WordToCGA CX ;Write the word JMP SHORT OutputExit ;Return ;Write with a BIOS call BiosOutput: MOV AL,CL ;AL = character MOV BL,CH ;BL = Video attribute MOV BH,CurrentPage ;BH = Current video page MOV CX,1 ;CX = number of chars to repeat VideoCall 9 ;Write character and attribute service OutputExit: POP DI ;Restore DI RET OutputChar ENDP ;****************************************************** DoLineFeed DoLineFeed PROC NEAR INC DH ;Next row CMP DH,WindMax.YHigh ;Still inside window? JBE DLFexit ;If so, go DEC DH ;Back up to current row PUSH BX ;save registers PUSH CX PUSH DI PUSH SI PUSH ES PUSH DX MOV BH,TextAttr ;Filler character MOV CX,WindMin ;Top row and left column MOV DX,WindMax ;Bottom row and right column MOV AL,1 ;AL = 1 (lines to scroll) CALL ScrollUpPrim ;Call scroll window up primitive POP DX POP ES ;Restore registers POP SI POP DI POP CX POP BX DLFexit: RET DoLineFeed ENDP ;****************************************************** WriteChar ;Write one character ;On entry, AL has character to write WriteChar PROC NEAR ;Save registers PUSH DI PUSH SI PUSH BX PUSH CX PUSH DX PUSH ES ;Get current position of cursor PUSH AX CALL GetCursorPrim POP AX ;Check for special characters CMP AL,CR ;Carriage return? JE CarriageReturn CMP AL,LineFeed ;Line feed? JE WCLineFeed CMP AL,BkSp ;Backspace? JE BackSpace CMP AL,Bell ;Bell (^G)? JE RingBell ;Normal character PUSH DX ;Save DX CALL OutputChar ;Write the character POP DX ;Restore DX ;Now move the cursor INC DL ;Cursor to next column CMP DL,WindMax.XHigh ;Still inside window? JBE WCSetCursor ;If so, move cursor and exit MOV DL,WindMin.XLow ;Else, do a 'carriage return'... JMP SHORT WCLineFeed ;... and 'line feed' RingBell: VideoCall 0Eh ;Write character as TTY JMP SHORT WCExit ;Done BackSpace: CMP DL,WindMin.XLow ;Cursor at start of this column? JE WCExit ;If so, do nothing DEC DL ;Else, previous column JMP SHORT WCSetCursor ;Move cursor and exit CarriageReturn: MOV DL,WindMin.XLow ;First column in window JMP SHORT WCSetCursor ;Move cursor and exit WCLineFeed: CALL DoLineFeed ;generate a line feed WCSetCursor: CALL SetCursorPrim WCExit: POP ES ;Restore registers POP DX POP CX POP BX POP SI POP DI RET WriteChar ENDP ;****************************************************** FlushString FlushString PROC NEAR PUSH CX ;save CX MOV CX,DI ;get number of characters to write SUB CX,SI JCXZ FSexit ;done if CX = 0 PUSH DX ;save registers used PUSH DI PUSH DS PUSH ES ;calculate address in video memory MOV AL,BH ;AL = row SetZero BH ;BH = 0 (BX = column) MUL ScreenWidth ;AL = (row * width) MOV DI,AX ;DI = (row * width) ADD DI,BX ;DI = (row * width) + column SHL DI,1 ;Account for attribute bytes MOV AH,TextAttr ;AH has attribute MOV AL,CheckSnow ;AL = CheckSnow MOV BX,VideoSegment ;BX = VideoSegment PUSH ES ;DS:SI points to string POP DS MOV ES,BX ;ES has segment of video memory ;determine which method of output to use CLD ;go forward OR AL,AL ;Snow checking off? JZ FSfast ;If so, go fast MOV DX,03DAh ;Point DX to CGA status port ;Use the following only for color cards when retrace checking is on FSgetNext: LODSB ;Load next character into AL MOV BX,AX ;Store video word in BX WaitForRetrace ;Wait for an opportunity to write WordToCGA BX ;Move the word LOOP FSgetNext ;Get next character JMP SHORT FSdone ;Done FSfast: LODSB ;load next character STOSW ;write it LOOP FSfast ;get next character FSdone: POP ES ;restore registers POP DS POP DI POP DX FSexit: POP CX RET FlushString ENDP ;****************************************************** WriteString ;on entry: ES:DI points to start of string, CX has its length WriteString PROC NEAR PUSH ES PUSH DI PUSH CX CALL GetCursorPrim ;Get cursor coordinates into DX POP CX POP DI POP ES MOV BX,DX ;save them in BX MOV SI,DI ;ES:SI points to start of string WSnext: MOV AL,ES:[DI] ;next character into AL CMP AL,CR ;check for control characters JA WSplain JE WScr CMP AL,LineFeed JE WSlinefeed CMP AL,BkSp JE WSbksp CMP AL,Bell JE WSbell WSplain: INC DI ;point to next character INC DL ;next column CMP DL,WindMax.XHigh ;past end of window? JBE WSskip ;if not, skip to next character CALL FlushString ;else, flush string CALL DoLineFeed ;do a line feed MOV DL,WindMin.XLow ;DL has first column JMP SHORT WSnoAdvance WSbell: CALL FlushString ;flush the string Write Bell ;sound the bell JMP SHORT WSadvance WSbksp: CALL FlushString ;flush the string CMP DL,WindMin.XLow ;already at first column? JE WSadvance ;if so, don't back up DEC DL ;else, previous column JMP SHORT WSadvance WSlinefeed: CALL FlushString ;flush the string CALL DoLineFeed ;do a line feed JMP SHORT WSadvance WScr: CALL FlushString ;flush the string MOV DL,WindMin.XLow ;DL has first column WSadvance: INC DI ;point to next character WSnoAdvance: MOV SI,DI ;SI = DI MOV BX,DX ;save cursor position WSskip: LOOP WSnext ;do it again CALL FlushString ;flush the string CALL SetCursorPrim ;position the cursor RET WriteString ENDP ;****************************************************** WriteCrt ;On entry, a pointer to an FIB is on the stack WriteCrt PROC FAR StackFrame GetPtr TextFile ;ES:DI points to file MOV CX,TFPtr.FBufPos ;CX = number of chars to write JCXZ WCrtExit ;Exit if string empty SUB TFPtr.FBufPos,CX ;Back up pointer to start of string GetPtr TFPtr.FBufPtr ;Point ES:DI to the start of the buffer MOV TextChar,' ' ;Force TextChar to ' ' CMP DirectVideo,True ;Write directly to screen? JNE WriteNext ;nope, write character at a time CMP InTextMode,True JNE WriteNext CALL WriteString ;else, write string at a time JMP SHORT WCrtExit ;we're done WriteNext: Write TFPtr ;Write the next character INC DI ;point to next char LOOP WriteNext ;Next character WCrtExit: CALL BreakCheck ;Check for ^Break SetZero AX ;Signal AOK RET 4 WriteCrt ENDP ;****************************************************** ReadCrt ;On entry, a pointer to an FIB is on the stack ;constants CrLf = 0A0Dh COMMENT | Register usage: BX always points to the next available slot in the text buffer CX contains a loop count (0 or 1). When CX = 0, LOOP instructions set CX to FFFFh, so the loop gets executed until some other condition is met. | ReadCrt PROC FAR StackFrameBP GetPtr TextFileBP ;ES:DI points to FileRec MOV SI,TFPtr.FBufPos ;SI = BufPos MOV CX,TFPtr.FBufSize ;CX = BufSize DEC CX DEC CX ;CX = 126 PUSH CX ;Save this for later SetZero BX ;Start at beginning of the buffer GetPtr TFPtr.FBufPtr ;ES:DI points to BufPtr^ MOV AX,BufLen ;AX = BufLen OR AX,AX ;AX = 0? JZ ResetBufLen ;If so, set it to the default CMP AX,CX ;BufLen > BufSize? JNA ReadNext ;If not, proceed ResetBufLen: MOV Buflen,CX ;BufLen = 126 ReadNext: MOV NextChar,Null ;Filter keys with extended scan codes CALL ReadKey ;Get next character into AL MOV CX,1 ;Loop counter = 1 CMP AL,BkSp ;Backspace? JE ReadBkSp CMP AL,CtrlS ;^S? (= Backspace) JE ReadBkSp CMP AL,CtrlD ;^D? (Restore one character) JE ReadRestore DEC CX ;BkSp loop counter = 0 CMP AL,Escape ;Escape? (Delete line) JE ReadBkSp CMP AL,CtrlBkSp ;^BkSp? (Delete line) JE ReadBkSp CMP AL,CtrlA ;^A? (Delete line) JE ReadBkSp CMP AL,CtrlF ;^F? (Restore whole line) JE ReadRestore CMP AL,CtrlZ ;^Z? (close Input?) JE ReadEofCheck ;If so, see if we should close shop CMP AL,Return ;Enter key? JE ReadCrlf ;If so, write a CrLf and stop CMP AL,' ' ;Regular ASCII character? JB ReadNext ;If not, continue ;Process the character CMP BX,BufLen ;Line full? JE ReadNext ;If so, don't add to it MOV TFPtr[BX],AL ;Add character to end of buffer CALL WriteChar ;Write the character INC BX ;Increment the buffer pointer CMP BX,SI ;BX > BufPos? JNA ReadNext ;If not, continue MOV SI,BX ;Else set BufPos to BX JMP SHORT ReadNext ReadExit: GetPtr TextFileBP ;ES:DI points to FileRec POP CX ;Get back default Buflen setting MOV BufLen,CX ;Reset BufLen to default SetZero AX ;No I/O error MOV TFPtr.FBufPos,AX ;Reset BufPos to 0 for next read MOV TFPtr.FBufEnd,BX ;FBufEnd has length of the string ExitCode 4 ReadRestore: CMP BX,SI ;Does BX point to end of buffer? JE ReadNext ;If so, do nothing MOV AL,TFPtr[BX] ;Next character into AL CMP AL,' ' ;Is it a control character? JB ReadNext ;If so, do nothing CALL WriteChar ;Write it INC BX ;Point to next character in buffer LOOP ReadRestore ;Repeat if CX was 0 on entry ReadJump: JMP SHORT ReadNext ReadEofCheck: CMP CheckEof,False ;CheckEof false? JE ReadNext ;If so, continue MOV TFPtr[BX],AL ;Add character to end of buffer INC BX ;Increment BX JMP SHORT ReadExit ;And exit ReadBkSp: OR BX,BX ;BX = 0? JZ ReadJump ;If so, don't back up Write BkSp ;Move the cursor back Write ' ' ;Overwrite the last character Write BkSp ;Move the cursor back again DEC BX ;Decrement buffer pointer LOOP ReadBkSp ;Repeat if CX was 0 on entry JMP ReadNext ;Continue ReadCrlf: WriteLn ;Write a CR/LF MOV WP TFPtr[BX],CrLf ;Add the CrLf to the buffer INC BX INC BX JMP SHORT ReadExit ;And exit ReadCrt ENDP ;****************************************************** OpenCrt ;Open input or output files ;Parameter is a pointer to an FIB COMMENT | Register usage: AX has offset of the Read/Write procedure BX Flush CX Close | OpenCrt PROC FAR StackFrame GetPtr TextFile ;ES:DI points to FileRec ;assume we're opening for input MOV CX,OFFSET CrtNop ;CX = Ofs(CrtNop) MOV BX,CX ;BX = Ofs(CrtNop) MOV AX,OFFSET ReadCrt ;AX = Ofs(ReadCrt) CMP TFPtr.FMode,FMInput ;Opening for input? JE OpenIt ;If so, AX-BX-CX are correct ;nope, opening for output MOV TFPtr.FMode,FMOutput ;Open for output MOV AX,OFFSET WriteCrt ;AX = Ofs(WriteCrt) MOV BX,AX ;BX = Ofs(WriteCrt) (Flush with write) OpenIt: SetPtr TFPtr.FInOutProc, CS, AX ;Set up Read/Write routine SetPtr TFPtr.FFlushProc, CS, BX ;Set up Flush routine SetPtr TFPtr.FCloseProc, CS, CX ;Do nothing with a Close() SetZero AX ;Signal success RET 4 OpenCrt ENDP ;****************************************************** AssignCrt ;procedure AssignCrt(var F : Text); ;Parameter is a pointer to an FIB AssignCrt PROC FAR StackFrame GetPtr TextFile ;ES:DI points to F MOV BX, OFFSET OpenCrt ;BX has offset of OpenCrt SetPtr TFPtr.FOpenProc, CS, BX ;Open with OpenCrt MOV TFPtr.FMode,FMClosed ;File is closed MOV TFPtr.FName,0 ;No filename LEA AX,TFPtr.FBuffer ;Set up file buffer MOV TFPtr.FBufPtr.Segm,ES ;Initialize record MOV TFPtr.FBufPtr.Ofst,AX MOV AX,128 ;AX = Default buffersize MOV TFPtr.FBufSize,AX ;Store Buffer size DEC AX DEC AX ;AX = Buffer size - 2 MOV BufLen,AX ;BufLen = Buffer size - 2 RET 4 AssignCrt ENDP ;****************************************************** ReInitCrt ;procedure ReInitCrt; ;Reinitialize CRT unit's internal variables. For TSR's or programs with ;DOS shells. ReInitCrt PROC FAR ;save current video mode CALL GetCrtModePrim ;Current video mode into AL ;check for EGA/VGA/etc. CALL AdapterCheck ;Check for EGA CALL WhichHercCard ;Check for Herc card type MOV WhichHerc,AL ;save it in WhichHerc ;set retrace checking variable MOV CheckSnow,False ;Assume false CMP IsCompaq,True ;Is it a Compaq? JE SetWindow ;If so, won't need to wait CMP CurrentDisplay,CGA ;CGA installed? JNE SetWindow ;If not, won't need to wait INC CheckSnow ;Else, may have to wait when writing ; to the color card SetWindow: CALL FullWindow ;set window coordinates RET ReInitCrt ENDP ;****************************************************** InitCrt ;procedure InitCrt; ;Initialization stuff InitCrt PROC NEAR ;Run test to see if DirectVideo will cause problems MOV DirectVideo,False ;try it with DirectVideo false CALL GetCursorPrim ;Get current coordinates into DX PUSH DX ;save result on stack MOV DirectVideo,True ;try it with DirectVideo on CALL GetCursorPrim ;Get current coordinates into DX POP AX ;first result into AX CMP AX,DX ;results the same? JE DirectVideoOK ;if so, DirectVideo=True presumably OK MOV DirectVideo,False ;else, force it to false DirectVideoOK: SetZero AL ;AL = 0 MOV NextChar,AL ;NextChar = 0 MOV CtrlBreakFlag,AL ;CtrlBreakFlag = False MOV WP ScreenWidth,80 ;ScreenWidth = 80 MOV WP VirtualWidth,80 CALL ReinitCrt ;Init code shared w/ ReInitCrt CALL GetAttribute ;get current attribute at cursor ;set up our ExitProc routine MOV AX, OFFSET CrtExitProc ;AX has offset of CrtExitProc GetPtr ExitProc ;ES:DI points to ExitProc^ SetPtr SaveExitProc, ES, DI ;Save current value of ExitProc SetPtr ExitProc, CS, AX ;Replace with address of CrtExitProc ;take over INT 1Bh MOV AX,351Bh ;AH = Get interrupt vector service ;AL = interrupt vector INT 21h ;Call DOS SetPtr Save1B, ES, BX ;Save pointer returned in ES:BX MOV DX,OFFSET Int1B ;DX = Ofs(Int1B) PUSH DS ;Save DS MOV AX,CS ;AX = CS MOV DS,AX ;DS = CS MOV AX,251Bh ;AH = Set interrupt vector service ;AL = interrupt vector INT 21h ;Call DOS POP DS ;Restore DS ;set up delay count MOV AX,40h ;AX = $40 MOV ES,AX ;ES = $40 MOV DI,6Ch ;ES:DI => low word of BIOS timer count MOV AL,ES:[DI] ;AL has first byte there STI WaitForChange: CMP AL,ES:[DI] ;wait for the byte to change JZ WaitForChange MOV AL,ES:[DI] ;see how many times DelayMS has to MOV CX,0FFFFh ;loop before the timer count changes CALL DelayMS MOV AX,55 ;now calculate OneMS XCHG CX,AX NOT AX XOR DX,DX DIV CX MOV OneMS,AX ;AX has OneMS RET InitCrt ENDP CODE ENDS END