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Assembly Source File | 1989-06-17 | 38.4 KB | 1,205 lines

;------------------------------------------------------------------------------ ; CUTPASTE.ASM ; Must be converted to a .COM file ;------------------------------------------------------------------------------ ; ;--------------- ;======= Equates ;--------------- ; ;------- Window WNDW_HT EQU 25 WNDW_WD EQU 80 ;------- Scan codes -- hot keys CUT_KEY EQU 7000H ; Alt-Fn9 PASTE_KEY EQU 6600H ; Ctl-Fn9 ;------- Scan code -- mark key MARK_CHAR EQU 3B00H ; Fn1 ;------- Scan codes -- cursor movement keys UP_ARROW EQU 4800H DOWN_ARROW EQU 5000H LEFT_ARROW EQU 4B00H RIGHT_ARROW EQU 4D00H CTL_RGT_ARW EQU 7400H ; Control-RightArrow CTL_LFT_ARW EQU 7300H ; Control-LeftArrow HOME_KEY EQU 4700H END_KEY EQU 4F00H TOP_PAGE EQU 4900H ; PageUp BOT_PAGE EQU 5100H ; PageDown ;------- Scan codes -- insert/delete keys CHAR_INS EQU 5200H DELETE EQU 5300H ; Delete (lower right) BACKSPACE EQU 0008H ; User rubout (^H) key LINE_INS EQU 000DH ; Enter DEL_TO_EOL EQU 4000H ; Fn6 LINE_DEL EQU 4100H ; Fn7 ;------- Scan codes -- carriage return CAR_RET1 EQU 000DH ; Carriage return (one byte) CAR_RET2 EQU 1C0DH ; Carriage return (two bytes) ;------- Characters and attributes BLANK EQU 0720H ; Define the blank character ATTR EQU 07H ; Default attribute (white on black) INV_ATTR EQU 70H ; Inverse of ATTR (black on white) ; ; ;======================================= Segment CODESEG ; COMSEG SEGMENT PARA PUBLIC 'CODE' ASSUME CS:COMSEG, DS:COMSEG, ES:COMSEG ORG 100H START LABEL NEAR JMP INSTALL ;------------------------- ;======= Data storage area ;------------------------- ; ;------- Copyright information COPYRITE DB 'Copyright Gerry Boyd, Larry Weiss, Randy Davis 1985 All Rights Reserved' DB '(214)238-9545' ;------- Buffer to hold screen contents SCRNSAVE DW ( WNDW_HT * (WNDW_WD+1) ) DUP(BLANK) ;------- Cursor location CURSOR_POS DW 0 OLD_CUR_POS DW 0 ;------- Old stack location SAVSTAKSP DW 0 SAVSTAKSS DW 0 ;------- Request type REQUEST LABEL WORD REQUEST0 DB 0 REQUEST1 DB 0 REQUEST2 DB 0 ;------- Original keyboard request handler address OLDINT16 LABEL DWORD OLDINT16IP DW 0 OLDINT16CS DW 0 ;------- Define the confines of the window LEFT_MARG DB 0 RIGHT_MARG DB 0 TOP_MARG DB 0 BOT_MARG DB 0 ;------- Feed chars to application MARK DW -1 ; Flag used in character feed FEED_START DW 0 ; Address in buffer of begin... FEED_STOP DW 0 ; ...and end of feed FEED_END1 DW 0 ; Temp holding spot for beg feed addr FEED_END2 DW 0 ; Temp holding spot for end feed addr FEED_CHAR DW 0 ; Char to feed on this call ;------- Display segment DISPLAY_SEG DW 0 ;------- Flag decribing movement of data between screen and buffer SWAP_SAVE DB 0 ;------------------- ;======= Subroutines ;------------------- ASSUME CS:COMSEG, DS:COMSEG, ES:NOTHING ;======= Proc CALC_WINDOW ; ; Calculate window extremeties and store them in ; RIGHT_MARG, LEFT_MARG, TOP_MARG, BOT_MARG ; CALC_WINDOW PROC NEAR ;------- Find out video mode for calculating window size MOV AH,0FH INT 10H ;------- Save the video segment MOV CX,0B000H ; Assume monochrome CMP AL,7 ; Look for mode 7 JZ CW100 ; Loop around if mono MOV CX,0B800H ; No, it's graphics CW100: MOV DISPLAY_SEG,CX ;------- Save window margins DEC AH ; Number of screen columns MOV RIGHT_MARG,AH MOV LEFT_MARG,0 MOV TOP_MARG,0 MOV BOT_MARG,WNDW_HT-1 ;------- Exit RET CALC_WINDOW ENDP ;======= Proc WINDOW_SAVE WINDOW_SAVE PROC NEAR MOV SWAP_SAVE,0 CALL WIN_SWP_SAV RET WINDOW_SAVE ENDP ;======= Proc WINDOW_SWAP WINDOW_SWAP PROC NEAR MOV SWAP_SAVE,0FFH CALL WIN_SWP_SAV RET WINDOW_SWAP ENDP ;======= Proc WIN_SWP_SAV ; ; When SWAP_SAVE=0, saves screen in buffer SCRNSAVE. ; When SWAP_SAVE=FF, exchanges contents of screen SCRNSAVE. ; This procedure does no BIOS calls -- all direct writes ; WIN_SWP_SAV PROC NEAR ; ;******* Setup for processing loop MOV CX,WNDW_HT ; Number of rows in window area MOV ES,DISPLAY_SEG ; Load up the video segment MOV SI,OFFSET SCRNSAVE ; Point SI at beginning of buffer XOR DI,DI ; DI indexes rows (lines) XOR BX,BX ; BX indexes columns (chars) ; ;******* Loop on lines WS050 LABEL NEAR MOV BL,LEFT_MARG ; Start on this line at left margin ;------- Process next character and attribute on line WS100: SHL BX,1 ; Change column number to byte pointer MOV AX,ES:[BX][DI] ; Get the next char/attr from screen XCHG AX,[SI] ; Store it and write saved char ADD SI,2 ; Move pointer over a word ;------- Perform swap/save check CMP SWAP_SAVE,0 ; Is this window swap or window save? JZ WS150 ; Loop around if a save MOV ES:[BX][DI],AX ; For swap, restore that char to screen ;------- Test for end of line WS150: SHR BX,1 ; Put byte offset back to col number INC BX CMP BL,RIGHT_MARG ; Are we beyond the end of the line? JNA WS100 ; No, branch and process next char ;------- Skip down to next line MOV [SI],CAR_RET2 ; So CRs are fed properly later ADD SI,2 ; Move pointer over a word SHL BX,1 ; Adjust DI by one line so that it... ADD DI,BX ; ...points to beginning of next line LOOP WS050 ; ;******* Exit RET WIN_SWP_SAV ENDP ;======= Proc EDITOR ; ; Check for edit keys (such as Ins, Del, etc). ; If not one of those, assume its ASCII and insert it in the screen. ; Return when `cut' hotkey detected. ; EDITOR PROC NEAR ; ;******* Get a character and prepare for processing ED100 LABEL NEAR ;------- Read a character from the keyboard CALL GET_CHAR ;------- If character is ASCII, then null out scan code OR AL,AL JZ ED105 XOR AH,AH ;------- Remove previous shading (if any) ED105: CALL UNSHAD_SCRN ;------- Place cursor position in BX (will become new cursor position) MOV BX,CURSOR_POS ;------- Check for and loop around if not `cut' hotkey pressed CMP AX,CUT_KEY JNZ ED120 ;------- `Cut' hotkey pressed -- set termination conditions MOV MARK,-1 MOV FEED_END1,0 MOV FEED_END2,0 ;------- Branch to end of routine JMP ED800 ; ;******* Simple cursor movement keys ;------- Left arrow ED120: CMP AX,LEFT_ARROW JNZ ED140 DEC BL JMP ED500 ;------- Right arrow ED140: CMP AX,RIGHT_ARROW JNZ ED160 INC BL JMP ED500 ;------- Up arrow ED160: CMP AX,UP_ARROW JNZ ED180 DEC BH JMP ED500 ;------- Down arrow ED180: CMP AX,DOWN_ARROW JNZ ED185 INC BH JMP ED500 ;------- Home ED185: CMP AX,HOME_KEY JNZ ED190 MOV BL,LEFT_MARG JMP ED500 ;------- End ED190: CMP AX,END_KEY JNZ ED195 MOV BL,RIGHT_MARG JMP ED500 ;------- PageUp ED195: CMP AX,TOP_PAGE JNZ ED200 MOV BH,TOP_MARG JMP ED500 ;------- PageDown ED200: CMP AX,BOT_PAGE JNZ ED205 MOV BH,BOT_MARG JMP ED500 ; ;******* Control-RightArrow and Control-LeftArrow ;------- Check for Control-RightArrow and set increment ED205: CMP AX,CTL_RGT_ARW JNZ ED210 MOV CL,1 ; Set increment to go forward JMP ED213 ;------- Check for Control-LeftArrow and set increment ED210: CMP AX,CTL_LFT_ARW JNZ ED220 CMP BL,LEFT_MARG JLE ED219 MOV CL,-1 ; Set increment to go backward DEC BL ; Begin one char to left ;------- Get and save character at current position ED213: MOV DX,BX ; Use DX for cursor for READ_CHAR CALL READ_CHAR ; Get char at current position MOV CH,AL ; Save current char in CH ;------- Move one character location and check if margin violated ED215: ADD DL,CL ; Move over one character CMP DL,RIGHT_MARG ; Stop at left/right margins JGE ED218 CMP DL,LEFT_MARG JLE ED218 ;------- Test for change from space to non-space CALL READ_CHAR ; Read current character CMP CH,' ' ; Branch if original... JNZ ED216 ; ...was not a space CMP AL,' ' ; Is this a space? JZ ED215 ; Yes, branch and repeat JMP ED217 ; No, stop ;------- Test for change from non-space to space ED216: CMP AL,' ' ; Is this a space? JNZ ED215 ; No, branch and repeat ;------- If we were going towards left then move to the right by one char ED217: CMP CL,-1 JNZ ED218 ADD DL,1 ;------- Place new cursor position in BX ED218: MOV BX,DX ;------- Branch to end of key processing loop ED219: JMP ED500 ; ;******* Erase remainder of line ;------- Test for, and go to next case if not, DEL_TO_EOL key ED220: CMP AX,DEL_TO_EOL JNZ ED240 ;------- Use ERASE_LINE proc to erase rest of line MOV DX,BX CALL ERASE_LINE ;------- Branch to end of key processing loop JMP ED500 ; ;******* Backspace ;------- Test for, and go to next case if not, BACKSPACE key ED240: CMP AX,BACKSPACE JNZ ED260 ;------- Move to left one space DEC BL ;------- Test and branch if we didn't move off screen CMP BL,LEFT_MARG JGE ED250 ;------- Put cursor at left margin and go to bottom of processing loop MOV BL,LEFT_MARG JMP ED500 ;------- Jump to Delete key processing to the actual delete ED250: JMP ED270 ; ;******* Delete key ED260 LABEL NEAR ;------- Test for and branch if not Del key CMP AX,DELETE JNZ ED280 ;------- Set CX to number of spaces to right of current position ED270: MOV CL,RIGHT_MARG SUB CL,BL XOR CH,CH ;------- Set DX to current cursor position MOV DX,BX ;------- Branch if CX is zero JCXZ ED275 ;------- Loop which moves CX characters one space to left ED272: INC DL CALL READ_CHAR DEC DL CALL WRITE_CHAR INC DL LOOP ED272 ;------- Place BLANK at current cursor position ED275: MOV AX,BLANK CALL WRITE_CHAR ;------- Branch to end of key processing loop JMP ED500 ; ;******* Insert key ED280 LABEL NEAR ;------- Test for, and go to next case if not, Insert key CMP AX,CHAR_INS JNZ ED300 ;------- Set DX to right margin of current row MOV DH,BH MOV DL,RIGHT_MARG ;------- Set CX to number of spaces to right of current position MOV CL,DL SUB CL,BL XOR CH,CH ;------- Branch if CX is zero JCXZ ED290 ;------- Loop which moves CX characters one space to right ED285: DEC DL CALL READ_CHAR INC DL CALL WRITE_CHAR DEC DL LOOP ED285 ;------- Place BLANK at current cursor position ED290: MOV AX,BLANK CALL WRITE_CHAR ;------- Branch to end of key processing loop JMP ED500 ; ;******* LINE_INS key ED300 LABEL NEAR ;------- Test for, and go to next case if not, LINE_INS key CMP AX,LINE_INS JNZ ED320 ;------- Start at the bottom margin MOV DH,BOT_MARG ;------- Start at the left margin ED305: MOV DL,LEFT_MARG ;------- Test for and branch if we're on the current line CMP DH,BH JZ ED315 ;------- Assign loop counter XOR CX,CX MOV CL,RIGHT_MARG INC CX ;------- Loop to move row of char/attr down ED310: DEC DH CALL READ_CHAR ; Get the character INC DH CALL WRITE_CHAR ; And put it back one line higher INC DL ; Move right one character LOOP ED310 ;------- Now move up a line and do it again DEC DH JMP ED305 ;------- Erase the current line ED315: CALL ERASE_LINE ;------- Branch to end of key processing loop JMP ED500 ; ;******* LINE_DEL key ED320 LABEL NEAR ;------- Test for, and go to next case if not, LINE_DEL key CMP AX,LINE_DEL JNZ ED340 ;------- Start at the left margin ED325: MOV DL,LEFT_MARG ;------- Test for and branch if we're on the last line CMP DH,BOT_MARG JZ ED335 ;------- Assign loop counter XOR CX,CX MOV CL,RIGHT_MARG INC CX ;------- Loop to move row of char/attr up ED330: INC DH CALL READ_CHAR ; Get the character DEC DH CALL WRITE_CHAR ; And put it back one line lower INC DL ; Move right one character LOOP ED330 ;------- Now move down a line and do it again INC DH JMP ED325 ;------- Erase bottom line on display ED335: CALL ERASE_LINE ; And wipe out the bottom line ;------- Branch to end of key processing loop JMP ED500 ; ;******* First MARK_CHAR ED340 LABEL NEAR ;------- Test for, and go to next case if not, `mark' hotkey CMP AX,MARK_CHAR JNZ ED400 ;------- Put cursor position in DX MOV DX,BX ;------- Test for and loop around if already marking CMP MARK,-1 JNZ ED350 ;------- Save cursor location in MARK MOV MARK,BX ;------- Branch to end of key processing loop JMP ED500 ; ;******* Second MARK_CHAR ;------- Store current location as FEED_END1 address in SCRNSAVE buffer ED350: CALL CONVERT_LOC MOV FEED_END1,AX ;------- Store previous mark location as feed end address SCRNSAVE buffer MOV DX,MARK CALL CONVERT_LOC MOV FEED_END2,AX ;------- Ensure that FEED_END1 is less than or equal to FEED_END2 MOV CX,FEED_END1 CMP CX,AX JNA ED360 MOV FEED_END1,AX MOV FEED_END2,CX ;------- Increase FEED_END2 by one cell ED360: MOV AX,FEED_END2 ADD AX,2 MOV FEED_END2,AX ;------- Trim unmarked chars from screen CALL TRIM_SCREEN ;------- Branch to exit routine JMP ED800 ; ;******* ASCII char -- write at current position ED400: MOV AH,ATTR CALL W_CHAR INC BL ; Move over one position ; ;******* Adjust cursor position ;------- Right margin ED500: CMP BL,RIGHT_MARG JLE ED520 MOV BL,RIGHT_MARG ;------- Left margin ED520: CMP BL,LEFT_MARG JGE ED540 MOV BL,LEFT_MARG ;------- Top margin ED540: CMP BH,TOP_MARG JGE ED560 MOV BH,TOP_MARG ;------- Bottom margin ED560: CMP BH,BOT_MARG JLE ED600 MOV BH,BOT_MARG ;------- Save new cursor position in CURSOR_POS ED600: MOV CURSOR_POS,BX ;------- Move cursor to the new position MOV DX,BX CALL PUT_CURSOR ;------- Jump to beginning of processing loop JMP ED100 ; ;******* End routine ED800: RET ; EDITOR ENDP ;======= Proc PUT_CURSOR ; ; Place cursor at location in DX ; PUT_CURSOR PROC NEAR ;------- If we are in mark mode, set the screen square to inverse video CALL SHADE_SCRN MOV AH,02H ; SET_CUR_POS service PUSH BX XOR BX,BX ; Page 0 INT 10H POP BX RET PUT_CURSOR ENDP UP_LEFT LABEL WORD ULHC_C DB 0 ULHC_R DB 0 LW_RIGHT LABEL WORD LRHC_C DB 0 LRHC_R DB 0 ATTRIB DB 0 SAVE_AX DW 0 SAVE_DX DW 0 ;======= Proc SHADE_SCRN ; ; Assigns INV_ATTR to characters in box defined by ; MARK and CURSOR_POS. Called by PUT_CURSOR. ; SHADE_SCRN PROC NEAR ; ;******* Initialization ;------- Test for, and branch to routine end, if not marking CMP MARK,-1 ; Is a mark set? JZ SS450 ;------- Save AX and DX registers MOV SAVE_AX,AX MOV SAVE_DX,DX ;------- First set the attribute to inverse MOV ATTRIB,INV_ATTR ; ;******* Place upper left-hand corner of shaded box in UP_LEFT ;------- Place current position in BX and marked position in AX MOV BX,CURSOR_POS MOV AX,MARK ;------- Place upper left-hand corner column value in AL CMP BL,AL JA SS100 MOV AL,BL ;------- Place upper left-hand corner row value in AH SS100: CMP BH,AH JA SS200 MOV AH,BH ;------- Store upper left-hand corner in UP_LEFT SS200: MOV UP_LEFT,AX ; ;******* Place lower right-hand corner of shaded box in LW_RIGHT ;------- Place marked position in AX MOV AX,MARK ;------- Place column value in AL CMP BL,AL JBE SS300 MOV AL,BL ;------- Place row value in AH SS300: CMP BH,AH JBE SS400 MOV AH,BH ;------- Store LRH corner in LW_RIGHT SS400: MOV LW_RIGHT,AX ; ;******* Call SS_COMMON to do the shading CALL SS_COMMON ; ;******* Return to caller SS450: RET SHADE_SCRN ENDP ;======= Proc UNSHAD_SCRN ; ; Assign ATTR to attributes of characters in the box defined ; by UP_LEFT and LW_RIGHT. Called by EDITOR, at the beginning ; of key processing. ; UNSHAD_SCRN PROC NEAR ; ;------- Test for, and branch to routine end, if not marking CMP MARK,-1 ; Here we unshade the shaded area JZ SS475 ;------- Save AX and DX registers MOV SAVE_AX,AX MOV SAVE_DX,DX ;------- Set the attribute to normal MOV ATTRIB,ATTR ; Change the box back to normal ;------- Call SS_COMMON to do the shading CALL SS_COMMON ;------- Return to caller SS475: RET ; UNSHAD_SCRN ENDP ;======= Proc SS_COMMON ; ; Assign ATTRIB to attributes of characters in the box defined ; by UP_LEFT and LW_RIGHT. ; SS_COMMON PROC NEAR ; ;******* Initialization ;------- Put box corners in BX and DX registers MOV DX,UP_LEFT ; DX is variable -- loc to change attr MOV BX,LW_RIGHT ; BX is constant ; ;******* Change attributes of row in DH ;------- Test and branch if past last column SS500: CMP DL,BL JA SS600 ;------- Change the attribute MOV AH,ATTRIB CALL WRITE_ATTR ;------- Point to next char on row and branch to top INC DL JMP SS500 ; ;******* Prepare to do next row ;------- Point to next row SS600: INC DH ;------- Branch if past last row CMP DH,BH JA SS700 ;------- Put first column in DL and branch MOV DL,ULHC_C JMP SS500 ; ;******* End program ;------- Restore AX and DX SS700: MOV AX,SAVE_AX MOV DX,SAVE_DX ;------- Return RET ; SS_COMMON ENDP ;======= Proc TRIM_SCREEN ; ; Trims the right margin of screen after the second mark ; TRIM_SCREEN PROC NEAR ; ;******* Initialization ;------- First clear mark MOV MARK,-1 ;------- Test and branch to return if at right-hand edge of screen MOV DL,LRHC_C CMP DL,RIGHT_MARG JZ TS200 ;------- Put space to right of upper right-hand corner in BX MOV BH,ULHC_R MOV BL,LRHC_C INC BL ;******* Loop to erase to right of box ;------- Place lower right-hand corner in DX TS100: MOV DX,LW_RIGHT ;------- Branch to end if BH equals DH CMP BH,DH JZ TS200 ;------- Erase end of current line MOV DX,BX CALL ERASE_LINE ;------- Increment current line and repeat INC BH JMP TS100 ; ;******* End routine TS200: RET TRIM_SCREEN ENDP ;======= Proc TRIM_BUF ; ; Trims blanks from first and last row in the feed area ; TRIM_BUF PROC NEAR ; ;******* Exit unless buffer holds data MOV BX,FEED_END2 CMP BX,FEED_END1 JZ TB070 ; ;******* Trim trailing blanks off last row ;------- Set CX to number of chars in a row XOR CX,CX MOV CL,LRHC_C SUB CL,ULHC_C INC CX ;------- Move backwards until first non-blank is found TB010: MOV AX,[BX-2] CMP AL,' ' JNZ TB020 SUB BX,2 LOOP TB010 ;------- Reassign FEED_END2 TB020: MOV FEED_END2,BX ; ;******* Check for, and skip over, a blank first line ;------- Branch and end if feed area corresponds to one row MOV AX,UP_LEFT CMP AH,LRHC_R JZ TB070 ;------- Set CX to number of chars in a row XOR CX,CX MOV CL,LRHC_C SUB CL,ULHC_C INC CX ;------- Point BX to start of feed area MOV BX,FEED_END1 ;------- Check for, and branch to end, if a non-blank char is found TB030: MOV AX,[BX] CMP AL,' ' JNZ TB070 ADD BX,2 LOOP TB030 ;------- Set AX to number of chars from left side to carriage return XOR AX,AX MOV AL,RIGHT_MARG INC AL SUB AL,ULHC_C ;------- Convert to words and add to FEED_END1 SHL AX,1 ADD FEED_END1,AX ;******* End routine TB070: RET ; TRIM_BUF ENDP ;======= Proc READ_CURSOR ; ; Find the current cursor location and place in DX ; READ_CURSOR PROC NEAR MOV AH,03H PUSH BX XOR BX,BX INT 10H POP BX RET READ_CURSOR ENDP ;======= Proc READ_CHAR ; ; Read character on screen at location in DX and place in AX ; READ_CHAR PROC NEAR ;------- Covert the row and column into location CALL CAL_VID_LOC ;------- Get the character and attribute at that location MOV AX,ES:[DI] RET READ_CHAR ENDP ;======= Proc R_CHAR ; ; Read character on screen at current cursor location and place in AX ; R_CHAR PROC NEAR MOV AH,08H PUSH BX XOR BH,BH INT 10H POP BX RET R_CHAR ENDP ;======= Proc WRITE_CHAR ; ; Write character and attribute in AX to screen at location in DX ; WRITE_CHAR PROC NEAR PUSH AX ; Save the attrib from destruction CALL CAL_VID_LOC ; Convert the row and col into location POP AX MOV ES:[DI],AX RET WRITE_CHAR ENDP ;======= Proc WRITE_ATTR ; ; Write attrib in AX to screen location in DX ; WRITE_ATTR PROC NEAR PUSH AX CALL CAL_VID_LOC POP AX MOV ES:[DI+1],AH RET WRITE_ATTR ENDP ;======= Proc W_CHAR ; ; Write character and attribute in AX at current cursor location ; W_CHAR PROC NEAR ;------- Save registers PUSH BX PUSH CX ;------- Do the write using INT 10H MOV BL,AH ; Place attribute in BL XOR BH,BH ; Page 0 MOV CX,1 ; Count = 1 MOV AH,09H ; WRITE_CHAR_ATTR service INT 10H ;------- Restore registers POP CX POP BX ;------- Exit RET W_CHAR ENDP ;======= Proc GET_CHAR ; ; Get character from keyboard into AX ; GET_CHAR PROC NEAR MOV AH,0 PUSHF CALL OLDINT16 RET GET_CHAR ENDP ;======= Proc ERASE_LINE ; ; Erase the current line on the screen from DX to RIGHT_MARG, inclusive ; ERASE_LINE PROC NEAR ;------- Set CX to number of columns to erase XOR CX,CX MOV CL,RIGHT_MARG SUB CL,DL INC CL ;------- Loop to blank row ER100: MOV AX,BLANK CALL WRITE_CHAR INC DL LOOP ER100 ;------- Exit routine RET ERASE_LINE ENDP ;======= Proc CONVERT_LOC ; ; Convert a location on the screen (in DX) into an offset in ; the SCRNSAVE buffer (in AX). ; CONVERT_LOC PROC NEAR ; ;******* Initialize ;------- Place line length (in bytes) in BX XOR BX,BX MOV BL,RIGHT_MARG INC BX INC BX SHL BX,1 ;------- Place location in CX MOV CX,DX ;------- Point AX at beginning of SCRNSAVE buffer MOV AX,OFFSET SCRNSAVE ; ;******* Loop to find row ;------- Test and branch if CH equals top row of window CL100: CMP CH,TOP_MARG JZ CL200 ;------- Add a row to AX and repeat test ADD AX,BX DEC CH JMP CL100 ; ;******* Loop to find column ;------- Test and branch if CL equals left margin of window CL200: CMP CL,LEFT_MARG JZ CL300 ;------- Add a column and repeat ADD AX,2 DEC CL JMP CL200 ; ;******* Exit CL300: RET CONVERT_LOC ENDP ;======= Proc CAL_VID_LOC ; ; Convert the screen location (row and column) in DX into an ; offset into the video display buffer in DI ; CAL_VID_LOC PROC NEAR ;------- Initialize AX, CX, DI to zero PUSH CX ; Save CX -- some callers need it XOR AX,AX ; AX holds line length XOR CX,CX ; CX is temp for location XOR DI,DI ; DI holds offset ;------- Set AX to line length in chars MOV AL,RIGHT_MARG INC AX ;------- Set CX to row number and branch if zero MOV CL,DH ; Put the number of rows into cx JCXZ CVL200 ;------- Increment DI by the line length times the row number CVL100: ADD DI,AX LOOP CVL100 ;------- Increment DI by the column number CVL200: MOV AL,DL ADD DI,AX ;------- End routine POP CX ; Restore CX SHL DI,1 ; Now convert this into byte offset MOV ES,DISPLAY_SEG RET CAL_VID_LOC ENDP ;------------------------------- ;======= Replacement for INT 16H ;------------------------------- ; ASSUME CS:COMSEG, DS:NOTHING, ES:NOTHING BEGIN PROC FAR ; ;======= Initial processing -- figure out what to do ; ;******* Check if in middle of feeding characters MAINLOOP LABEL NEAR ;------- Save caller's AX register MOV REQUEST,AX AND AH,0EFH MOV REQUEST2,AH ;------- Branch if we're in the middle of feeding characters MOV AX,FEED_START ; Are we in the middle of feeding... CMP AX,FEED_STOP ; ...chars to the application? JZ NOFEED ; No, loop around JMP FEED ; Yes, branch ; ;******* Test for type-0 request and return if not NOFEED LABEL NEAR ;------- Restore caller's AX MOV AX,REQUEST ;------- Check for type-0 request -- only interested in char requests CMP REQUEST2,0 JZ CONTINU ;------- Jump to old INT 16 routine, which will return to application JMP OLDINT16 ; ;******* Now check for a hot key -- return if not CONTINU LABEL NEAR ;------- Call old INT 16H (emulate interrupt) PUSHF CALL OLDINT16 ;------- Check for Alt-Fn9 CMP AX,CUT_KEY JZ GOT_CUT_KEY ;------- Check for Ctl-Fn9 CMP AX,PASTE_KEY JZ PASTE_CHAR ;------- Not a hotkey -- provide keystroke to caller IRET ; ;======= `Cut' hotkey processing ; ;******* Setup for subroutine calls GOT_CUT_KEY LABEL NEAR ;------- Save stack and point SS:SP to top of PSP MOV SAVSTAKSS,SS MOV SAVSTAKSP,SP MOV AX,CS MOV SS,AX MOV SP,100H ;------- Enable interrupts while processing characters STI ;------- Set up a stack frame PUSH BP MOV BP,SP ;------- Save registers SUB SP,0EH CALL SAVEREG ;------- Set DS to COMSEG MOV DS,AX ASSUME DS:COMSEG ; ;******* Call EDITOR and other subroutines ;------- Calculate window extremeties CALL CALC_WINDOW ;------- Save the cursor for later restoring CALL READ_CURSOR MOV OLD_CUR_POS,DX ;------- Save screen in buffer SCRNSAVE CALL WINDOW_SAVE ;------- Restore cursor in edit window MOV DX,CURSOR_POS CALL PUT_CURSOR ;------- Edit in the window CALL EDITOR ;------- Save cursor in edit window for next edit CALL READ_CURSOR MOV CURSOR_POS,DX ;------- Put back whatever was originally there CALL WINDOW_SWAP ;------- Trim blanks from end of buffer CALL TRIM_BUF ;------- Restore the cursor position MOV DX,OLD_CUR_POS CALL PUT_CURSOR ; ;******* End `cut-key' processing ;------- Restore registers CALL RESTREG ADD SP,0EH ASSUME DS:NOTHING ;------- Restore stack POP BP MOV SS,SAVSTAKSS MOV SP,SAVSTAKSP ;------- End of loop -- jump to beginning MOV AX,REQUEST ; Restore request JMP MAINLOOP ; Get another char to return to caller ; ;======= `Paste' hotkey processing ; ;******* Paste characters into application PASTE_CHAR LABEL NEAR MOV AX,FEED_END1 MOV FEED_START,AX MOV AX,FEED_END2 MOV FEED_STOP,AX MOV AX,REQUEST ; Restore request JMP MAINLOOP ; Go get another character to return ; ;******* Feed characters to application from the buffer SCRNSAVE FEED LABEL NEAR ;------- Test and branch for return if a type-2 request CMP REQUEST2,1 JA KSTAT ;------- Get next char from SCRNSAVE buffer into AX PUSH BX MOV BX,AX MOV AX,CS:[BX] POP BX ;------- Loop around if end of screen line CMP AX,CAR_RET2 JZ FEED10 ;------- Null attribute XOR AH,AH ;------- Save in FEED_CHAR FEED10: MOV FEED_CHAR,AX ;------- Test and branch if type-1 request CMP REQUEST2,0 JNZ FEED_STAT ;------- Point to next character ADD FEED_START,2 ; ;******* Handle beginning and end of line ;------- Test for and loop around if not carriage return CMP AL,CAR_RET1 JNZ FEED20 ;------- Skip to beginning of the feed area PUSH DX XOR DX,DX MOV DL,ULHC_C SHL DX,1 ; In words ADD FEED_START,DX POP DX ;------- Put address of next buffer location in BX FEED20: PUSH BX MOV BX,FEED_START ;------- Test, and branch to return, if at end of feed area FEED30: CMP BX,FEED_STOP JZ FEED50 ;------- Test and loop around if next char is space MOV AX,CS:[BX] CMP AL,' ' JZ FEED40 ;------- Test and branch if a non-space char follows on this line CMP AX,CAR_RET2 JNZ FEED50 ;------- Point to carriage return, skipping over trailing blanks MOV FEED_START,BX JMP FEED50 ;------- Point to next char on line and branch to top of loop FEED40: INC BX INC BX JMP FEED30 ; ;******* Exit to caller ;------- Exit for type-0 request -- returning character to application FEED50 LABEL NEAR POP BX ; Restore stack MOV AX,FEED_CHAR ; Place char to feed in AX IRET ; Return char to application ;------- Exit for type-1 request: enable interrupts, feed ZF = NZ and char FEED_STAT LABEL NEAR STI RET 02 ;------- Exit for type-2 request -- invoke INT 16H to do what he wants KSTAT: MOV AX,REQUEST JMP OLDINT16 BEGIN ENDP ;======= Proc SAVEREG ;------- Save registers on stack frame SAVEREG PROC NEAR MOV [BP-2],BX MOV [BP-4],CX MOV [BP-6],DX MOV [BP-8],SI MOV [BP-0AH],DI MOV [BP-0CH],DS MOV [BP-0EH],ES RET SAVEREG ENDP ;======= Proc RESTREG ;------- Now put the registers back RESTREG PROC NEAR MOV BX,[BP-2] MOV CX,[BP-4] MOV DX,[BP-6] MOV SI,[BP-8] MOV DI,[BP-0AH] MOV DS,[BP-0CH] MOV ES,[BP-0EH] RET RESTREG ENDP ;------- Upper limit resident program (paras) RESPARA EQU ($-START+100H+15)/16 ;------------------------- ;======= Installation code ;------------------------- INSTALL LABEL NEAR ASSUME CS:COMSEG, DS:COMSEG, ES:COMSEG ;------- Output 'OK' message MOV DX,OFFSET MESSAGE MOV AH,09H INT 21H ;------- Get existing 16H vector using ES:BX MOV AX,3516H INT 21H MOV OLDINT16IP,BX MOV OLDINT16CS,ES ASSUME ES:NOTHING ;------- Now put our routine there using DS:DX MOV AX,2516H MOV DX,OFFSET BEGIN INT 21H ;------- Terminate and stay resident MOV DX,RESPARA MOV AX,3100H INT 21H MESSAGE DB 10,13,'CUTPASTE installed',10,13 DB ' Alt-Fn9 to enable cut ',10,13 DB ' Start/stop marking: Fn1',10,13 DB ' Move 1 space (4 ways): Cursor keys', 10,13 DB ' Move 1 word (2 ways): Ctl-LeftArw, Ctl-RgtArw', 10,13 DB ' Move to screen edge (4 ways): Home, End, PgUp, PgDn', 10,13 DB ' Erase to End of Line: Fn6', 10,13 DB ' Erase Line: Fn7', 10,13 DB ' Add Line: Enter', 10,13 DB ' Move text to right/left: Ins, Del, Bksp', 10,13 DB ' Ctl-Fn9 to paste',10,13,'$' COMSEG ENDS END START