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Assembly Source File | 1985-07-27 | 28.9 KB | 1,004 lines

PAGE 55,132 TITLE NOTEPAD4 ; ;NotePad IV - NON BIOS VERSION ; Permission is granted to copy and distribute freely copies of this ; program with the following restrictions: ; ; 1) this program be passed in the public domain ; 2) a fee, beyond the cost of the disk, not be charged ; 3) improvements not be passed on but rather sent to me ; to check for possible incompatibilities with other programs ; ; (Stephen) Randy Davis and Larry Weiss ; (214)454-2426 ; ; feel free to call with bugs or questions ; ;PARAMETERS -- MOST OF THESE MAY BE CHANGED TO ANY DESIRED VALUE wndw_ht equ 24 ;mark the size of the window to open wndw_wd equ 40 our_key equ 07100H ;scan code - ascii of key to open window ;now scan codes of edit keys (AltF10) up_arrow equ 4800H down_arrow equ 5000H left_arrow equ 4B00H right_arrow equ 4D00H del_left equ 0008H ;user rubout (cntrl H) key delete equ 5300H ;use del (lower right) insert equ 5200H cr equ 000DH home equ 4700H escape equ 001BH tab equ 7400H ; ^right arrow rev_tab equ 7300H ; ^left arrow line_ins equ 5100H ;pg down line_del equ 4900H ;pg up mark_char equ 4F00H ;end key print_char equ 372AH ;PrtSc* = print note on printer file_change equ 4A2DH ;key to update file and get a new one blank equ 07020H ;define the character which is a blank attrib equ 070H ;and our default attribute (should agree with blank) video equ 10H ;video BIOS call inv_attrib equ 007H ;inverse of 'attrib' PAGE CSEG SEGMENT PARA PUBLIC 'CODE' ASSUME CS:CSEG,DS:CSEG,SS:CSEG,ES:NOTHING ;STANDARD DECL FOR .COM FILE ORG 100H Start: JMP INSTALL ;PLACE DATA AREA HERE FOR READIBILITY COPYRITE DB 'Copyright Stephen R. Davis, Larry Weiss 1985 All Rights Reserved' DB '(214)454-2426' SCREENSAVE: DW (WNDW_HT * (WNDW_WD+1)) DUP (BLANK);RESERVE SPACE TO SAVE OPENED WINDOW LINESAVE: DW WNDW_WD DUP (BLANK) ;BUFFER FOR LINE DELETE CURSOR_POS DW 0 OLD_CUR_POS DW 0 SAVESTACK DW 0,0 REQUEST DB 0 ;REQUEST TYPE KEY_RQST_HANDLER DD 0 ;ADDRESS OF THE ORIGINAL KEYBOARD REQUEST HANDLER LEFT_MARG DB 00 ;define the confines of the window RIGHT_MARG DB 00 TOP_MARG DB 00 BOT_MARG DB 00 UPPER_LEFT DW 00 MARK DW 00 ;FLAGS USED IN CHARACTER FEED FEED_START DW 00 ;ADDRESS IN BUFFER OF BEGIN... FEED_END DW 00 ;...AND END OF FEED DISPLAY_SEG DW 00 ;DISPLAY SEGMENT (B000 -> MONOCHROME, ; B800 -> GRAPHIX) FILE_NM_LOC DW 00 ;ADDRESS OF FILE NAME (0 -> NO FILE) PAGE BEGIN PROC FAR ;FAR LABEL SINCE ITS ENTERED BY INTERRUPT MAINLOOP: MOV CS:REQUEST,AH ;SAVE HIS AX REGISTER MOV AX,CS:FEED_START ;ARE WE IN THE MIDDLE OF FEEDING CHARS... CMP AX,CS:FEED_END ;...TO THE APPLICATION? JZ NOFEED ;NO JMP FEED ;YES NOFEED: MOV AH,CS:REQUEST ;RESTORE USERS AX PUSHF ;CALL OLD INTERRUPT HANDLER (EMULATE INT INSTRUCTION) CALL DWORD PTR [CS:KEY_RQST_HANDLER] ;GO AHEAD AND GET THE CHARACTER PUSHF ;SAVE THE FLAG RETURNED (FOR AH = 1 REQUESTS) CMP CS:REQUEST,00H ;WE ARE ONLY INTERESTED IN CHAR. REQUESTS JZ CNTINUE JMP FORGET_IT CNTINUE: ;YES -- CHECK CHARACTER FOR 'OURS' POPF ;FOR NON-TYPE 1 REQUESTS DONT NEED TO SAVE FLAGS CMP AX,OUR_KEY JZ CNT_AGIN JMP RETURN_CHAR CNT_AGIN: ;WE GOT IT! GO INTO EDITOR MODE MOV CS:SAVESTACK,SP MOV CS:SAVESTACK+2,SS MOV AX,CS MOV SS,AX MOV SP,100H STI ;ENABLE INTERRUPTS WHILE PROCESSING CHARACTERS PUSH BP ;SET UP A STACK FRAME MOV BP,SP SUB SP,0EH CALL SAVEREG MOV DS,AX CALL CALC_WINDOW ;CALCULATE WINDOW EXTREMETIES CALL READ_CURSOR MOV OLD_CUR_POS,DX ;SAVE THE CURSOR FOR LATER RESTORING CALL WINDOW_SWAP ;SWING IN THE EDIT WINDOW (WITH NOTES?) CALL INSERT_CR ;PUT THE CARRIAGE RETURNS ON UNPRINTABLE COL.S MOV DX,CURSOR_POS ;RESTORE CURSOR IN EDIT WINDOW CALL PLACE_CURSOR CALL EDITOR ;LET HIM EDIT IN THE WINDOW CALL READ_CURSOR MOV CURSOR_POS,DX ;SAVE CURSOR IN EDIT WINDOW FOR NEXT EDIT CMP MARK,00H ;CLEAR THE MARK POSITION (IF IT'S SET) JZ NOT_SET MOV DX,MARK CALL READ_CHAR ;GET THE CHARACTER... MOV AH,ATTRIB ;...PUT ITS ATTRIBUTE BACK TO EVERYONE ELSE'S... CALL WRITE_CHAR ;...AND PUT IT BACK MOV MARK,00H NOT_SET: CALL WINDOW_SWAP ;PUT BACK WHATEVER WAS ORIGINALLY THERE CALL UPDATE_FILE ;NOW ATTEMPT TO UPDATE THE DISK FILE MOV DX,OLD_CUR_POS ;RESTORE THE CURSOR POSITION CALL PLACE_CURSOR CALL RESTREG ADD SP,0EH POP BP MOV SS,CS:SAVESTACK+2 MOV SP,CS:SAVESTACK MOV AH,00 ;RESTORE REQUEST TO SOMETHING DECENT JMP MAINLOOP ;GO GET ANOTHER CHARACTER TO RETURN HIM RETURN_CHAR: IRET ;RETURN WITH CHARACTER ;HANDLE REQUEST TYPE 1'S BY FAR RETURNING 2 AND TYPE 2'S BY JUST RETURNING FORGET_IT: CMP CS:REQUEST,1 ;was it a "is char present" request? JZ FI100 POPF ;no -- just return whatever BIOS returned IRET FI100: POPF ;yes -- make funny return RET 02 PAGE ;HERE WE ARE IN THE PROCESS OF FEEDING CHARACTERS TO THE APPLICATION ;FROM THE WINDOW BUFFER (SCREENSAVE) FEED: CMP CS:REQUEST,1 ;WAS THIS A CHAR TYPE REQUEST? JA KSTAT ;YES -- RETURN HIM CHAR PUSH BX ;GET THE NEXT CHARACTER FROM THE BUFFER CALL SKIP_SPACES ;STRIP LEADING SPACES MOV BX,CS:FEED_START ;OK - GET THE NEXT CHARACTER WE NEED MOV AX,CS:[BX] POP BX XOR AH,AH ;WE NO LONGER HAVE THE SCAN CODE, BUT ALL ;ARE ASCII ANYWAY CMP CS:REQUEST,0 ;IS THIS A 'GET KEYBOARD CHAR' RQST? JNZ FEED_KEY_STAT ADD CS:FEED_START,2 ;YES -- MOVE UP THE POINTER BY 1 IRET FEED_KEY_STAT: STI ;NO -- ENABLE INTERRUPTS AND FEED HIM THE RET 02 ;THE Z FLAG CLEAR WITH HIS CHAR KSTAT: MOV AH,CS:REQUEST ;RESTORE REQUEST TO AH CALL DWORD PTR [CS:KEY_RQST_HANDLER] ;PERFORM BIOS CALL -- WE DON'T KNOW ;WHAT HE'S DOING AND WE SHOULDN'T GET IN THE WAY IRET ;RETURN THE RESULTS TO HIM (WHATEVER THEY ARE) BEGIN ENDP PAGE BODY PROC NEAR ;MAKE SHORT CALLS ONLY TO THE MAIN ROUTINES SKIP_SPACES: ;TRY TO AVOID FEEDING SPACES WITH NOTHING AFTER THEM ON A LINE -- ;JUST SKIP OVER TO THE RETURN AND FEED THAT ALONE MOV BX,CS:FEED_START ;START WITH THE NEXT FEED CHARACTER LOOK_AHEAD: MOV AX,CS:[BX] CMP AL,CR ;IS THIS CHAR A RETURN JZ STRIP_SPACES CMP AL,' ' ;IS THIS CHARACTER ANOTHER SPACE? JNZ GO_ON ADD BX,2 ;YES -- KEEP LOOKING AHEAD CMP BX,CS:FEED_END ;IS THAT IT? JNZ LOOK_AHEAD ;YES-- SUB BX,2 ;RAN OFF THE END -- BACK UP ONE CHAR AT LEAST! STRIP_SPACES: MOV CS:FEED_START,BX ;HERE WE FOUND NOTHING BUT SPACES BEFORE THE ;CARRIAGE RETURN -- SKIP THAT! GO_ON: RET PAGE CALC_WINDOW: MOV AH,0FH ;FIND OUT VIDEO MODE FOR CALCULATING WINDOW SIZE INT VIDEO ;GO AHEAD AND GET THE CHARACTER MOV CX,0B000H ;IS IT MONOCHROME? CMP AL,7 ;WELL LOOK FOR MODE 7 JZ CW100 MOV CX,0B800H ;NO -- ITS GRAPHIX CW100: MOV DISPLAY_SEG,CX ;SAVE THIS OFF DEC AH ;THIS IS THE NUMBER OF COLS ON SCREEN MOV RIGHT_MARG,AH ;SET UP RIGHT AND LEFT MARGINS SUB AH,(WNDW_WD - 1) MOV LEFT_MARG,AH MOV TOP_MARG,0 ;WE HAVE NO INFORMATION ON NUMBER OF ROWS MOV BOT_MARG,WNDW_HT-1 ;SO WE MUST ASSUME SOMETHING NORMAL (IT ISNT ;AS CRITICAL ANYWAY) MOV AL,AH ;NOW ADD UPPER_LEFT HAND CORNER VALUE XOR AH,AH MOV UPPER_LEFT,AX CMP CURSOR_POS,0 ;IF THIS IS THE FIRST TIME WEVE DONE THIS... JNZ CW200 MOV CURSOR_POS,AX ;...PLACE THE CURSOR IN THE UPPER LEFT HAND CORNER CW200: RET PAGE INSERT_CR: ;INSERT CARRIAGE RETURNS 1 PAST RIGHT MARGIN MOV CX,WNDW_HT MOV SI,OFFSET SCREENSAVE MOV BX,WNDW_WD ADD BX,BX ;EVERY LOCATION TAKES A WORD, NOT A BYTE ICR_LOOP: ADD SI,BX ;GO 1 BEYOND RIGHT MARGIN MOV [SI],CR ADD SI,2 ;THAT CR TAKES A SPACE LOOP ICR_LOOP RET WRITE_POS DW 0 WINDOW_SWAP: MOV CX,WNDW_HT ;GET THE NUMBER OF ROWS IN WINDOW AREA MOV SI,OFFSET SCREENSAVE;START AT BEGINNING OF BUFFER MOV ES,DISPLAY_SEG ;LOAD UP THE VIDEO SEGMENT MOV DI,00 XOR BX,BX WS050: MOV BL,LEFT_MARG ;START ON THIS LINE AT THE LEFT MARGIN WS100: SHL BX,1 ;CHANGE THE COLUMN NUMBER TO BYTE POINTER MOV AX,ES:[BX][DI] ;GET THE NEXT CHARACTER FROM SCREEN XCHG AX,[SI] ;STORE IT AWAY AND WRITE THE SAVED CHARACTER ADD SI,2 ;AND MOVE SAVE POINTER OVER A WORD MOV ES:[BX][DI],AX ;NOW RESTORE THAT CHARACTER TO THE SCREEN SHR BX,1 ;PUT THE BYTE OFFSET BACK TO COLUMN NUMBER INC BX CMP BL,RIGHT_MARG ;ARE WE BEYOND THE END OF THE LINE? JNA WS100 ;YES -- SKIP DOWN TO NEXT LINE ADD SI,2 ;SKIP BEYOND CARRIAGE RETURN SHL BX,1 ADD DI,BX LOOP WS050 RET PAGE EDITOR: ;first check for "special" keys -- print screen and close file ;if not one of these, check for edit keys (such as insert, delete, etc.) ;if not one of those, assume its ascii and just insert it in the notepad ;return when AltF10 detected. ED100: CALL GET_CHAR ;read a character from the keyboard CMP AX,PRINT_CHAR ;check for print note first JNZ ED102 CALL PRINTNOTE ;we need to print the note -- not change it MOV BX,CURSOR_POS ;in many cases we need the cursor position JMP ED500 ED102: CMP AX,FILE_CHANGE ;is he wanting to close and open a new file JNZ ED103 CALL CHANGE_FILE MOV BX,CURSOR_POS JMP ED500 ED103: OR AL,AL ;if this is ascii then dont retain scan code JZ ED105 XOR AH,AH ED105: MOV BX,CURSOR_POS ;in many cases we need the cursor position CMP AX,OUR_KEY ;check for exit JNZ ED110 JMP ED800 ED110: CMP AX,CR ;check for each special character individually JNZ ED120 MOV BL,LEFT_MARG INC BH JMP ED500 ED120: CMP AX,LEFT_ARROW JNZ ED140 DEC BL JMP ED500 ED140: CMP AX,RIGHT_ARROW JNZ ED160 INC BL JMP ED500 ED160: CMP AX,UP_ARROW JNZ ED180 DEC BH JMP ED500 ED180: CMP AX,DOWN_ARROW JNZ ED200 INC BH JMP ED500 ED200: CMP AX,HOME JNZ ED205 MOV BX,UPPER_LEFT JMP ED500 ED205: ;tab and back tab functions CMP AX,TAB JNZ ED210 MOV CL,1 ;go forward JMP ED213 ED210: CMP AX,REV_TAB JNZ ED220 MOV CL,0FFH ;go backwards one tab slot ADD DL,CL ;start one char to left initially ED213: CALL READ_CHAR ;get char at current position MOV CH,AL ;save it for comparison ED215: ADD DL,CL ;move over one character CMP DL,RIGHT_MARG ;stop at left and right margins (or beyond) JGE ED218 CMP DL,LEFT_MARG JLE ED218 CALL READ_CHAR ;read current character CMP CH,' ' ;if original was a space... JNZ ED216 CMP AL,' ' ;...then go until not space JZ ED215 JMP ED217 ED216: CMP AL,' ' ;...else, go until space JNZ ED215 ED217: CMP CL,0FFH ;if we were going backwards (towards left)... JNZ ED218 ADD DL,1 ;...then scoot back to the right by 1 ED218: MOV BX,DX JMP ED500 ED220: CMP AX,ESCAPE ;wipe out remainder of line JNZ ED240 MOV DX,BX CALL ERASE_LINE JMP ED500 ED240: CMP AX,DEL_LEFT ;move cursor left one char and then do normal del JNZ ED260 DEC BL CMP BL,LEFT_MARG JNB ED250 MOV BL,RIGHT_MARG CMP BH,00 JZ ED250 DEC BH ED250: JMP ED270 ED260: CMP AX,DELETE ;in delete char we... JNZ ED280 ED270: MOV CL,RIGHT_MARG SUB CL,BL ;calculate how many chars to right margin XOR CH,CH MOV DX,BX ;...start at current cursor position... JCXZ ED275 ED272: INC DL ;...get character just to the right... CALL READ_CHAR DEC DL ;...move left one position... CALL WRITE_CHAR ;...and write it there... INC DL ;...now do it again for the char to the right... LOOP ED272 ;...for the distance from cursor to right margin;... ED275: MOV AX,BLANK CALL WRITE_CHAR JMP ED500 ED280: CMP AX,INSERT ;in the case of insert we do reverse of delete JNZ ED300 MOV DH,BH ;start at the right margin MOV DL,RIGHT_MARG MOV CL,DL ;caculate number of spaces to right SUB CL,BL XOR CH,CH JCXZ ED290 ED285: DEC DL CALL READ_CHAR INC DL CALL WRITE_CHAR DEC DL LOOP ED285 ED290: MOV AX,BLANK CALL WRITE_CHAR JMP ED500 ED300: CMP AX,LINE_INS ;check for insert line JNZ ED320 MOV DH,BOT_MARG ;we're going to need that ED305: MOV DL,LEFT_MARG ;always start at the far left CMP DH,BH ;are we on our current line? JZ ED315 ;no -- then move it down MOV CX,WNDW_WD 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 DEC DH ;now move up a line and do it again JMP ED305 ED315: MOV BL,LEFT_MARG ;move us over the far left marg CALL ERASE_LINE ;and wipe out the line we are on JMP ED500 ED320: CMP AX,LINE_DEL ;and check for line delete JNZ ED340 ED325: MOV DL,LEFT_MARG ;always start at the far left CMP DH,BOT_MARG ;are we on the last line? JZ ED335 ;no -- then move it up MOV CX,WNDW_WD 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 INC DH ;now move down a line and do it again JMP ED325 ED335: MOV BL,LEFT_MARG ;move us over the far left marg of our line CALL ERASE_LINE ;and wipe out the bottom line JMP ED500 ED340: CMP AX,MARK_CHAR ;check for mark JNZ ED400 MOV DX,BX CMP MARK,00H ;if mark isnt set... JNZ ED350 MOV MARK,BX ;...just set it and switch its attrib CALL READ_CHAR MOV AH,INV_ATTRIB CALL WRITE_CHAR JMP ED500 ED350: ;else, store off feed start and end addresses CALL CONVERT_LOC MOV FEED_START,AX MOV DX,MARK CALL CONVERT_LOC MOV FEED_END,AX MOV CX,FEED_START CMP CX,AX JNA ED355 MOV FEED_START,AX MOV FEED_END,CX ED355: JMP ED800 ;note that this char exits the note pad ED400: ;wasnt an edit character -- must be ascii ;just write the character at current position MOV AH,ATTRIB CALL W_CHAR INC BL ;move over one position ED500: ;adjust resulting cursor position CMP BL,RIGHT_MARG JNA ED550 MOV BL,RIGHT_MARG ED550: CMP BH,BOT_MARG JNA ED600 MOV BH,BOT_MARG ED600: CMP BL,LEFT_MARG JNB ED650 MOV BL,LEFT_MARG ED650: CMP BH,0FFH ;special case for a top margin of 0 JNZ ED700 MOV BH,BOT_MARG ED700: MOV CURSOR_POS,BX MOV DX,BX ;be sure and move the cursor to the new CALL PLACE_CURSOR ;position JMP ED100 ED800: ;exit RET PAGE PRINTNOTE: CALL P_SPLAT_ROW ;put a row of splats across the top ;to delineate the note on the printer page MOV DX,UPPER_LEFT PN100: CMP DL,LEFT_MARG ;put a splat on left hand side also JNZ PN150 MOV AL,2AH CALL PRINT_C JNZ PN400 ;don't proceede on timeout of printer PN150: CALL READ_CHAR ;get the character @ DX CALL PRINT_C ;and print it JNZ PN400 ;quit immediatly on i/o timeout CMP DL,RIGHT_MARG JNZ PN200 MOV AL,2AH ;print a right margin delineator CALL PRINT_C MOV AL,0AH ;print carriage return-line feed after every line CALL PRINT_C MOV AL,0DH CALL PRINT_C CMP DH,BOT_MARG ;are we finished? JZ PN300 ;no -- drop down a line INC DH MOV DL,LEFT_MARG DEC DL PN200: INC DL ;skip over to next character in note JMP PN100 PN300: CALL P_SPLAT_ROW PN400: RET P_SPLAT_ROW: MOV CX,WNDW_WD+2 ;put a row of splats across the page PS100: MOV AL,2AH CALL PRINT_C JNZ PS200 ;return immediately on time out LOOP PS100 MOV AL,0AH CALL PRINT_C MOV AL,0DH CALL PRINT_C PS200: RET PAGE ; ; THE FOLLOWING ROUTINE CLOSES THE CURRENT FILE AND ASKS FOR A NEW ; FILE; IT ATTEMPTS TO OPEN THIS FILE UP AND READ IT AS A NOTE PAD ; CHANGE_FILE: CALL WINDOW_SWAP ;PUT THE NOTE PAD INTO THE SAVE BUFFER FOR WRITING CALL UPDATE_FILE ;IF CURSOR HOMED, WRITE THE NOTEPAD OUT TO THE CURRENT FILE MOV FILE_NM_LOC,0 ;THAT FILE IS NOW CLOSED PERMANENTLY MOV DX,UPPER_LEFT ;ERASE THE TOP LINE AND POSE FILE NAME QUESTION MOV BX,DX CALL ERASE_LINE MOV DX,BX CALL PLACE_CURSOR ;PUT CURSOR ON LEFT AND ASK FOR FILE NAME MOV BX,OFFSET CF500 CF100: MOV AL,BYTE PTR [BX] INC BX CMP AL,0 ;0 TERMINATES AN ASCIIZ STRING JZ CF200 MOV AH,ATTRIB CALL W_CHAR INC DL CALL PLACE_CURSOR JMP CF100 CF200: MOV BX,80H ;STORE NAME IN PSP CF300: CALL GET_CHAR ;GET FILE NAME UNTIL RETURN CMP AL,0DH ;CHECK FOR RETURN JZ CF400 CMP AL,08H ;WE DO NEED TO HANDLE DEL CHAR SEPERATLY JNZ CF350 DEC BX ;HE'S TRYING TO DELETE THE LAST CHAR DEC DL ;MOVE THE POINTER BACK IN THE FILE AND DEL CHAR MOV AL,20H ;ON SCREEN W/ A SPACE MOV AH,ATTRIB CALL WRITE_CHAR JMP CF300 CF350: INC BX ;SAVE OFF NEXT CHARACTER OF NAME FIELD MOV BYTE PTR [BX],AL MOV AH,ATTRIB CALL W_CHAR ;ECHO CHAR SO HE CAN SEE WHAT HE IS TYPING INC DL CALL PLACE_CURSOR JMP CF300 CF400: SUB BX,80H ;CALCULATE CHARACTER COUNT MOV BYTE PTR [80H],BL MOV DL,LEFT_MARG ;NOW ERASE NAME OF FILE AND RESTORE WHAT WAS THERE MOV BX,DX CALL RESTORE_LINE CALL READ_FILE ;READ UP THE INDICATED FILE INTO SAVE BUFFER CALL WINDOW_SWAP ;NOW PUT NOTE PAD DISPLAY BACK UP RET CF500: DB 'ENTER FILE NAME:',0 READ_FILE: ;READS FILE NAME IN 81 WITH LENGTH COUNT IN 80 ;ON SUCCESSFUL READS, RETURNS CARRY CLEARED MOV BX,80H ;FIND BEGINNING OF NAME FIELD XOR CH,CH MOV CL,BYTE PTR [BX] ;GO GET THE ARGUMENT COUNT FROM THE PSP JCXZ RF300 RF100: ;FIND THE BEGINNING OF THE FILE NAME INC BX CMP BYTE PTR [BX],20H JNZ RF150 LOOP RF100 RF150: MOV DI,BX ;NOW TERMINATE IT WITH A 0 JCXZ RF300 ;A 0 LENGTH FILE NAME INDICATES NO FILE TO READ MOV FILE_NM_LOC,BX ;SAVE THE LOCATION OF THE NAME RF200: INC DI LOOP RF200 MOV BYTE PTR [DI],0 MOV AH,3DH ;OPEN FILE MOV AL,0 ;FILE FOR READ ONLY MOV DX,BX ;PUT FILE NAME IN GOOD REGISTER INT 21H JC RF400 ;CARRY SET INDICATES OPEN ERROR MOV BX,AX ;READ THE FILE INTO THE NOTE PAD AREA MOV CX,(WNDW_HT*(WNDW_WD+1)*2) MOV DX,OFFSET SCREENSAVE MOV AH,3FH INT 21H MOV AH,3EH ;CLOSE THE FILE INT 21H RF300: CLC ;MAKE SURE CARRY CLEAR FOR NO ERROR RETURN RET RF400: RET ;LEAVE CARRY SET ON ERROR RETURN UPDATE_FILE: CMP FILE_NM_LOC,0 ;IF THERE IS NOT FILE... JZ UP100 ;...THEN JUST SKIP THIS WHOLE THING MOV AX,CURSOR_POS ;UPDATE IF CURSOR HOMED CMP AX,UPPER_LEFT JNZ UP100 MOV AL,1H ;OPEN THE FILE FOR WRITING MOV AH,3DH MOV DX,FILE_NM_LOC ;GET THE FILENAME IN DX INT 21H JC UP100 ;IF ERROR ON OPEN, JUST GIVE IT UP MOV BX,AX MOV AH,40H ;WRITE THE FILE MOV CX,(WNDW_HT*(WNDW_WD+1)*2) MOV DX,OFFSET SCREENSAVE INT 21H MOV AH,3EH INT 21H ;NOW CLOSE THE FILE UP100: RET PAGE ; ; HERE WE PLACE SOME SMALL GENERAL PURPOSE ROUTINES ; PRINT_C: ;print the char in AL on LPT1 (parrallel) ;returns printer status in AH PUSH DX XOR DX,DX ;select LPT1 XOR AH,AH ;select "print" INT 17H POP DX TEST AH,1 ;set the zero flag if not error, ;clear zero flag if char not printed RET PLACE_CURSOR: ;place cursor at location in dx MOV AH,2H PUSH BX XOR BX,BX INT VIDEO POP BX RET READ_CURSOR: ;read cursor location into dx MOV AH,3H PUSH BX XOR BX,BX INT VIDEO POP BX RET READ_CHAR: ;read screen character at location in dx CALL CALC_VID_LOC ;covert the row and column into location MOV AX,ES:[DI] ;get the character at that location RET R_CHAR: ;read screen char at current cursor location MOV AH,8H PUSH BX XOR BH,BH INT VIDEO POP BX RET WRITE_CHAR: ;write attrib/char in ax at location in dx PUSH AX ;save the attrib from destruction CALL CALC_VID_LOC ;convert the row and column into location POP AX MOV ES:[DI],AX RET W_CHAR: ;write character at current cursor location PUSH BX ;save bx register MOV BL,AH XOR BH,BH PUSH CX ;retain cx register also MOV CX,1 MOV AH,9H INT VIDEO POP CX POP BX RET CALC_VID_LOC: ;convert the row and column in dx into an ;offset into the video display buffer XOR AX,AX XOR DI,DI PUSH CX ;save cx -- some of those who call us need it XOR CX,CX MOV AL,RIGHT_MARG ;get the width of a row INC AX MOV CL,DH ;put the number of rows into cx JCXZ CVL200 CVL100: ADD DI,AX ;for every row add in another 80/40 columns LOOP CVL100 CVL200: MOV AL,DL ;now move over to the current column ADD DI,AX POP CX ;restore cx SHL DI,1 ;now convert this into byte offset MOV ES,DISPLAY_SEG RET GET_CHAR: ;get character from keyboard into ax MOV AH,0H PUSHF ;simulate call to keyboard handler CALL DWORD PTR [KEY_RQST_HANDLER] RET ERASE_LINE: ;erase the current line from dx to right margin MOV CL,RIGHT_MARG SUB CL,BL INC CL XOR CH,CH MOV SI,OFFSET LINESAVE ER100: CALL READ_CHAR ;get the character @ current location MOV [SI],AX ADD SI,2 MOV AX,BLANK CALL WRITE_CHAR INC DL LOOP ER100 RET RESTORE_LINE: ;restore the current line from dx to right margin MOV CL,RIGHT_MARG SUB CL,BL INC CL XOR CH,CH MOV SI,OFFSET LINESAVE RL100: MOV AX,[SI] ;get the saved char CALL WRITE_CHAR ;put the saved char where indicated ADD SI,2 INC DL LOOP RL100 RET CONVERT_LOC: ;convert a location on the screen (in dx) into location ;in the screen save buffer MOV CX,DX MOV AX,OFFSET SCREENSAVE CL100: CMP CH,TOP_MARG JZ CL200 ADD AX,(WNDW_WD+1)*2 DEC CH JMP CL100 CL200: CMP CL,LEFT_MARG JZ CL300 ADD AX,2 DEC CL JMP CL200 CL300: RET SAVEREG: MOV -2[BP],BX ;save reggies on stack frame MOV -4[BP],CX MOV -6[BP],DX MOV -8[BP],SI MOV -0AH[BP],DI MOV -0CH[BP],DS MOV -0EH[BP],ES RET RESTREG: MOV BX,-2[BP] ;NOW PUT THE REGGIES BACK AND PULL DOWN MOV CX,-4[BP] ;THE STACK FRAME MOV DX,-6[BP] MOV SI,-8[BP] MOV DI,-0AH[BP] MOV DS,-0CH[BP] MOV ES,-0EH[BP] RET BODY ENDP PAGE INSTALL: ;THIS PROGRAM INSTALLS THE REST OF THE CODE FOR NOTE PAD ;TRY TO READ THE INITIAL FILE UP INTO THE NOTE PAD AREA CALL READ_FILE JNC GO_AHEAD ;ON ERROR READING FILE... ;...OUTPUT ERROR MESSAGE AND QUIT MOV DX,OFFSET ERRMSG MOV AH,9H INT 21H MOV AH,4CH MOV AL,1 ;SET THE ERROR LEVEL INT 21H GO_AHEAD: MOV DX,OFFSET MESSAGE ;OUTPUT 'OK' MESSAGE MOV AH,9H INT 21H MOV AX,3516H ;GET INTERRUPT 16 VECTOR INT 21H MOV WORD PTR KEY_RQST_HANDLER,BX MOV WORD PTR KEY_RQST_HANDLER+2,ES MOV AX,2516H MOV DX,OFFSET BEGIN ;NOW PUT OUR ROUTINE THERE INT 21H MOV DX,OFFSET INSTALL ;TERMINATE AND STAY RESIDENT ADD DX,100H MOV CL,4 SHR DX,CL MOV AH,31H INT 21H MESSAGE DB 10,13,'NotePad4 installed',10,13,'Alt-F10 to enter and exit',10,13,'$' ERRMSG DB 10,13,'NotePad4 not installed',10,13,'Error on file read',10,13,'$' CSEG ENDS END START