Informática Multimedia 1995 April

home *** CD-ROM | disk | FTP | other *** search

/ Informática Multimedia 1995 April / Informatica Multimedia CD - Epimundo.iso / DOS / FILEVIEW / VIEW.ZIP / VIEW.ASM < prev next >

Wrap

Assembly Source File | 1993-06-10 | 9.7 KB | 471 lines

; A86 source code for VIEW.COM v2.1 BUFFER EQU 0600 ;allow 2k for code + data + stack HALF_READ EQU 07C00 ;31k = half read buffer FULL_READ EQU HALF_READ + HALF_READ BUFFER_TOP EQU BUFFER + FULL_READ SHIFT EQU 16 ;right arrow key shift ORG 0100 JMP SHORT START VIDEO_ADDR DW 'DD' VIDEO_SEG DW 0B800 PLACE_MARK DW BUFFER SCR_ROWS DW 0 CGA_MODE DB 0 NO_FILE DB 'No File$' NO_MEMORY DB 'Out of RAM$' START: CLD CMP SP, 65530 ;FFFE = 65,534 JAE PARSE MOV DX, OFFSET NO_MEMORY QUIT: MOV AH, 9 INT 021 INT 020 PARSE: MOV SI, 081 ;point to command line parameters L1: LODSB ;load into AL, increase SI CMP AL, 020 ;space? JE L1 ;then skip CMP AL, 0D ;carriage return? JE FILE_ERROR CMP AL, '/' ;possible delimiter JNE OPEN_FILE LODSB AND AL, 0DF MOV W[PATCH], 020CD ;modify code - INT 020 CMP AL, 'R' ;redirect JNE FILE_ERROR XOR BX, BX MOV AH, 045 ;duplicate file handle INT 021 MOV W[FILE_HANDLE], AX ;save HANDLE MOV AH, 03E ;close file INT 021 MOV BX, 2 MOV AH, 045 INT 021 JMP SHORT A1 FILE_ERROR: MOV DX, OFFSET NO_FILE JMP QUIT OPEN_FILE: MOV DX, SI ;point DX at string DEC DX ;remember SI was advanced L2: LODSB CMP AL, 0D ;CR end of line? JE PUT_ZERO CMP AL, 020 ;space between parameters? JNE L2 PUT_ZERO: MOV B[SI-1], 0 ;end string with zero, for Asciiz MOV AX, 03D00 ;OPEN file for reading INT 021 JC FILE_ERROR MOV W[FILE_HANDLE], AX A1: MOV AH, 0F ;video mode in AL INT 010 CMP AL, 7 ;monochrome 80 x 25 JE VIDEO_INFO CMP AL, 3 ;color text 40 x 25 or 80 x 25 JBE VIDEO_INFO MOV AX, 03 ;force color text if necessary INT 010 VIDEO_INFO: MOV AX, 040 ;BIOS data area MOV ES, AX ES MOV AX, W[063] ;display card MOV W[PORT_ADDRESS], AX TEST AL, 020 ;03B4 = mono 03D4 = color JZ COLOR ; 1011 0100 1101 0100 MOV VIDEO_SEG, 0B000 ;mono segment address JMP SHORT NO_CGA COLOR: MOV AH, 012 ;returns EGA info MOV BL, 010 INT 010 CMP BL, 010 ;if unchanged, then CGA JNE NO_CGA MOV CGA_MODE, 1 NO_CGA: ES MOV AX, W[04E] ;offset to current page MOV VIDEO_ADDR, AX MOV AH, 0F INT 010 ;page in BH, AH = screen width MOV B[PAGE_NUM+1], BH MOV B[SCR_COLUMNS], AH ES MOV AL, B[084] ;character rows on screen INC AL MOV B[SCR_ROWS], AL PUSH CS POP ES MOV AH, 8 ;read screen char (pg in BH) INT 010 MOV B[ATTRIBUTE], AH MOV AH, 03 ;find cursor function INT 010 ;CH start - CL stop - scan line MOV W[USER_CURSOR+1], CX MOV AH, 01 ;these 3 lines to remove cursor MOV CH, 020 ;blank cursor code INT 010 MOV DX, OFFSET ERROR_HANDLE MOV AX, 02523 INT 021 MOV B[INPUT_COUNT], 0 ;initialize data area at end MOV W[LOW_OFFSET], 1 CALL HOME ;set SI = BUFFER A5: LEA BP, BLANK_SCREEN DISPLAY: CALL SHOW_PAGE GET_ASCII: MOV AH, 8 ;get key INT 021 CMP AL, 01B ;ESC JE ERROR_HANDLE CMP AL, '*' JNE GET_SCAN XOR B[WORDSTAR+1], 080 ;AND with 07F to turn off high bit JMP A5 GET_SCAN: CMP AL, 0 JNZ GET_ASCII MOV AH, 8 INT 021 SUB AL, 047 ;ready for key table JB GET_ASCII CMP AL, 0C JA GET_ASCII CBW SHL AX, 1 ;double it for WORD table MOV BX, AX MOV SI, W[PLACE_MARK] LEA BP, BLANK_SCREEN CALL KEY_TABLE[BX] ;process each key press MOV W[PLACE_MARK], SI JMP DISPLAY ERROR_HANDLE: USER_CURSOR: MOV CX, 0B0C ; (self modify) restore normal cursor MOV AH, 1 INT 010 PATCH: MOV BX, W[FILE_HANDLE] ; (self modify) make INT 020 for MOV AH, 03E ; redirection, else CLOSE file INT 021 INT 020 KEY_TABLE DW HOME, UP, PGUP, NONE, LEFT, NONE, RIGHT, NONE DW ENDY, DOWN, PGDN, DO_SEARCH, SEARCH_AGAIN ;ins del HOME: XOR BX, BX MOV AX, W[LOW_OFFSET] OR AX, W[HIGH_OFFSET] MOV W[LOW_OFFSET], BX MOV W[HIGH_OFFSET], BX MOV W[SHIFT_RIGHT], BX MOV SI, BUFFER JZ RET MOV DX, BUFFER MOV CX, FULL_READ CALL READ_FILE RET UP: CALL BACKUP JC NONE MOV BP, OFFSET NEW_UP UP2: CALL BACKUP B1: CALL BACKUP ;step back with SI JC RET CMP AL, 0A JNE B1 ;go till find LF CALL FORWARD RET ENDY: MOV SI, W[END_BYTE] CMP SI, BUFFER_TOP JBE PGUP CALL FORWARD2 JMP ENDY PGUP: MOV CX, W[SCR_ROWS] CALL BACKUP JC NONE B2: CALL UP2 LOOP B2 RET LEFT: CMP W[SHIFT_RIGHT], 0 MOV W[SHIFT_RIGHT], 0 JNZ RET NONE: POP AX ;get rid of RET address from stack JMP GET_ASCII RIGHT: MOV AL, SHIFT CBW ADD W[SHIFT_RIGHT], AX RET DOWN: MOV BP, OFFSET NEW_DOWN DOWN2: CALL FORWARD JC RET CMP AL, 0A JNE DOWN2 RET PGDN: MOV CX, W[SCR_ROWS] B4: CALL DOWN2 LOOP B4 JC NONE RET SHOW_PAGE: PUSH ES MOV SI, W[PLACE_MARK] MOV ES, W[VIDEO_SEG] CALL BP ;blank screen, scroll up or down MOV AL, B[SCR_COLUMNS] CBW ADD AX, W[SHIFT_RIGHT] MOV W[TOTAL_SHIFT], AX XOR DL, DL B7: XOR BX, BX MOV AL, B[SCR_COLUMNS] MUL DL SHL AX, 1 MOV DI, AX ADD DI, W[VIDEO_ADDR] NEXT_LINES: CALL FORWARD ;get char in AL, advance SI JC END_PAGE WORDSTAR: AND AL, 0FF ;flipflop 0FF & 07F, turn off high bit CMP AL, 0D ;CR JE NEXT_LINES CMP AL, 0A ;LF JE NEW_LINE CMP AL, 09 ;TAB JE TAB MOV CX, 1 C2: CMP BX, W[SHIFT_RIGHT] JB C6 CMP BX, W[TOTAL_SHIFT] JAE C6 MOV AH, B[ATTRIBUTE] CMP SI, W[SEARCH_MARK] IF E XOR AH, 0F7 ;inverse attribute, blink CMP B[CGA_MODE], 0 JZ C5 PUSH BX PUSH DX MOV BX, AX MOV DX, W[PORT_ADDRESS] ADD DX, 6 ;status register HORIZ_RETRACE: IN AL, DX SHR AL, 1 JC HORIZ_RETRACE CLI ;Disable interupts. WAITER: IN AL, DX SHR AL, 1 JNC WAITER MOV AX, BX STOSW STI ;Enable interupts. POP DX POP BX JMP SHORT C6 C5: STOSW C6: INC BX LOOP C2 JMP NEXT_LINES TAB: MOV AX, BX ;adjust column counter AND AX, 07 ;get bottom three bits MOV CX, 08 ;adjust SUB CX, AX MOV AL, 020 ;pad spaces JMP C2 NEW_LINE: INC DL CMP DL, B[SCR_ROWS] JB B7 END_PAGE: POP ES RET FORWARD: CMP SI, W[END_BYTE] JAE D2 CMP SI, BUFFER_TOP JB D1 FORWARD2: PUSH CX PUSH DX PUSH DI PUSH ES PUSH DS POP ES MOV SI, BUFFER + HALF_READ MOV DI, BUFFER MOV CX, HALF_READ SUB W[PLACE_MARK], CX REP MOVSB MOV SI, DI ADD W[LOW_OFFSET], FULL_READ ADC W[HIGH_OFFSET], 0 MOV DX, BUFFER + HALF_READ MOV CX, HALF_READ CALL READ_FILE SUB W[LOW_OFFSET], HALF_READ SBB W[HIGH_OFFSET], 0 POP ES POP DI POP DX POP CX JMP FORWARD D1: LODSB D2: CMC ;Complement carry flag. RET BACKUP: CMP SI, BUFFER JA D3 MOV AX, W[LOW_OFFSET] OR AX, W[HIGH_OFFSET] JZ D4 PUSH CX PUSH DX MOV SI, BUFFER MOV DI, BUFFER + HALF_READ MOV CX, HALF_READ ADD W[PLACE_MARK], CX REP MOVSB SUB W[LOW_OFFSET], HALF_READ SBB W[HIGH_OFFSET], 0 MOV DX, BUFFER MOV CX, HALF_READ CALL READ_FILE POP DX POP CX D3: DEC SI MOV AL, B[SI] CLC ;Clear the carry flag. RET D4: STC RET READ_FILE: PUSH AX PUSH BX PUSH CX PUSH DX MOV W[SEARCH_MARK], 0 MOV W[END_BYTE], 0FFFF MOV DX, W[LOW_OFFSET] ;CX:DX offset in file (begin 0) MOV CX, W[HIGH_OFFSET] MOV BX, W[FILE_HANDLE] MOV AX, 04200 ;set file read pointer INT 021 POP DX POP CX MOV AH, 03F ;read file INT 021 JNC D5 XOR AX, AX D5: CMP AX, CX ;bytes read JE D6 ADD AX, DX MOV W[END_BYTE], AX D6: POP BX POP AX RET BLANK_SCREEN: MOV AX, 0600 JMP SHORT D8 NEW_UP: MOV AH, 07 JMP SHORT D7 NEW_DOWN: MOV AH, 06 D7: MOV AL, 1 D8: XOR CX, CX ;top left corner 0, 0 MOV DL, B[SCR_COLUMNS] DEC DL MOV DH, B[SCR_ROWS] ;DX lower right corner 24, 79 DEC DH MOV BH, B[ATTRIBUTE] INT 010 RET DO_SEARCH: MOV AX, 0920 ;write without moving the cursor PAGE_NUM: MOV BH, 0 ;(self modify) active display page MOV BL, B[ATTRIBUTE] MOV CX, 60 ;# of chars for buffer is 60 INT 010 MOV AX, 0E BY '?' ;TTY write of question mark INT 010 MOV CX, 010C ;block cursor MOV AH, 1 INT 010 MOV W[INPUT_SIZE], 61 ;INPUT_SIZE = 61, INPUT_COUNT = 0 MOV DX, OFFSET INPUT_SIZE MOV AH, 0A ;get buffered keyboard input INT 021 MOV AH, 01 ;these 3 lines to remove cursor MOV CH, 020 ;blank cursor code INT 010 CMP B[INPUT_COUNT], 0 JZ RET CALL HOME ;SI at buffer JMP SHORT SET_UP SEARCH_AGAIN: CMP B[INPUT_COUNT], 0 IF Z JMP NONE CALL DOWN2 CALL DOWN2 JMP SHORT SET_UP READ_MORE: CMP W[END_BYTE], 0FFFF ;middle of file? JNE SEARCH_DONE CALL FORWARD2 DEC SI SET_UP: MOV DI, SI ;DI in file MOV SI, OFFSET INPUT ;SI at search entry LODSB ;AL first character for search MOV CX, W[END_BYTE] CMP CX, BUFFER_TOP IF A MOV CX, BUFFER_TOP SUB CX, DI ;CX bytes to search FIND_MATCH: REPNE SCASB JCXZ READ_MORE PUSH CX ;first character matches PUSH DI PUSH SI MOV CL, B[INPUT_COUNT] XOR CH, CH DEC CL REPE CMPSB ;compare with search input POP SI POP DI POP CX JNE FIND_MATCH MOV W[SEARCH_MARK], DI ;record position SEARCH_DONE: MOV SI, DI CALL UP2 CALL UP2 LAST: RET DATA SEGMENT ORG OFFSET LAST+1 ATTRIBUTE DB ? SCR_COLUMNS DB ? PORT_ADDRESS DW ? LOW_OFFSET DW ? HIGH_OFFSET DW ? SHIFT_RIGHT DW ? TOTAL_SHIFT DW ? FILE_HANDLE DW ? END_BYTE DW ? SEARCH_MARK DW ? INPUT_SIZE DB ? ;buffered keyboard input, 1st byte buffer size INPUT_COUNT DB ? ;next byte = number of characters read INPUT DB 61 DUP ? ;buffer for 60 characters (plus CR) DATA ENDS