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Assembly Source File | 1989-04-26 | 30.1 KB | 789 lines

PAGE 78,132 TITLE "SLICE - Break file for multiple diskettes" CSEG SEGMENT PARA PUBLIC 'CODE' ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG ; --------------------------------------------------------------------------- ; DTA structure for DOS "find matching" call ; --------------------------------------------------------------------------- ORG 80H ; dta offset DTA DB 21 dup (0) ; start of find file area DTA_ATTR DB 0 ; file attribute DTA_TIME DW 0 ; file time DTA_DATE DW 0 ; file date DTA_LSIZ DW 0 ; file lsw of size DTA_HSIZ DW 0 ; file msw of size DTA_NAME DB 12 DUP (0) ; file name of file DTA_LEN EQU $-DTA ; length of dta find entry ORG 100H ; start of program area START: JMP MAIN ; go to the code ; --------------------------------------------------------------------------- ; Common initialized work areas ; --------------------------------------------------------------------------- ARG DW 0 ; addr of first argument FLOPDRV DB 0,":\" ; output drive letter DESTFILE DB " ",0 ; output file name DESTEXT DW 0 ; pointer to extension DESTEXTC DB "0" ; 1st character of extension DESTNBR DW 1 ; file extension counter RSTFLAG DB 0 ; slice/restore flag CURRDIR DB ".",0 ; argument for current directory IHANDLE DW 0 ; input file handle OHANDLE DW 0 ; output file handle ; --------------------------------------------------------------------------- ; Messages to user ; --------------------------------------------------------------------------- HEADER_MSG DB "SLICE 1.0 - (c) 1989 Ziff Communications Co.",0DH,0AH DB "PC Magazine ",254," Bob Flanders & Michael Holmes",0AH DB 0DH,0AH DOLLAR DB "$" FILENF DB "File not found$" NOCREATE DB "Error opening output$" NOROOM DB "Not enough room$" WRONGDISK DB "Wrong restore disk, insert number " DISKNO DB "XX$" DRVNR DB "Must be removable media$" RDERROR DB "Error reading input$" WRTERROR DB "Error writing output$" FILEFND DB "File exists$" NEXTDISK DB "Next diskette$" HITANYKEY DB ", Press any key ..",0DH,0AH,"$" FORMAT DB 0DH,0AH,"format:",09H,"$" RSFORM DB "SPLICE d: d:[\path]",0DH,0AH,"$" RESTORING DB "Restoring: " RESTFILE DB 12 DUP (" "),0DH,0AH,"$" ; --------------------------------------------------------------------------- ; File ID Header ; --------------------------------------------------------------------------- RSTLAST DB 0 ; last file flag RSTATTR DB 0 ; file attributes RSTTIME DW 0 ; file time RSTDATE DW 0 ; file date RSTLSIZ DW 0 ; file lsw of size RSTHSIZ DW 0 ; file msw of size RSTNAME DB 12 DUP (0) ; file name of file RST_FFLEN EQU $-RSTATTR ; length to move from ff area RSTSDTE DD 0 ; date .. RSTSTME DD 0 ; ..and time of save RST_LEN EQU $-RSTLAST ; length of our file header ; --------------------------------------------------------------------------- ; MAIN - Mainline of program ; --------------------------------------------------------------------------- MAIN PROC ; start of program CMP RSTFLAG, 0 ; q. restoring? JNZ RESTORE ; a. goto restore section CALL INIT ; initialize program CALL PARMS ; check parameters CALL OPEN ; open the input file CALL SAVE ; copy/slice the file to output JMP SHORT MAIN10 ; return to dos RESTORE: CALL INIT ; perform restore setup CALL PARMS ; check parameters CALL ROPEN ; open the output file CALL RFILE ; restore the file MAIN10: MOV DX, OFFSET DOLLAR ; dx -> null message CALL DIE ; .. say goodnight MAIN ENDP ; --------------------------------------------------------------------------- ; INIT - Handle initialization ; --------------------------------------------------------------------------- INIT PROC CLD ; assure ascending MOV DX, OFFSET HEADER_MSG ; dx -> header message MOV AH, 9 ; ah = print ascii$ message INT 21H ; .. ask DOS to do it RET ; return to caller INIT ENDP ; --------------------------------------------------------------------------- ; ROPEN - open the file to restore ; --------------------------------------------------------------------------- ROPEN PROC MOV DI, OFFSET ROPENFILE ; di -> work area MOV SI, ARG ; si -> where to restore ROPEN10: MOVSB ; move a character CMP BYTE PTR [SI], 0 ; q. end of parm? JNE ROPEN10 ; a. yes .. continue CMP BYTE PTR [DI-1], "\" ; q. last byte a back-slash? JE ROPEN20 ; a. yes .. continue CMP BYTE PTR [DI-1],":" ; q. last byte a colon (drive)? JE ROPEN20 ; a. yes .. continue MOV AL, "\" ; end as directory STOSB ROPEN20: MOV SI, OFFSET RSTNAME ; si -> name of original file MOV BX, OFFSET RESTFILE ; bx -> restore filename ROPEN30: LODSB ; al = char of filename STOSB ; .. save it OR AL, AL ; q. end of file name? JZ ROPEN40 ; a. yes .. continue MOV [BX], AL ; save in message INC BX ; bx -> next char JMP ROPEN30 ; .. continue ROPEN40: MOV AH, 4EH ; ah = find first MOV DX, OFFSET ROPENFILE ; dx -> file to find MOV CX, 0FFH ; .. any attribute INT 21H ; q. file found? JC ROPEN45 ; a. no .. continue MOV DX, OFFSET FILEFND ; dx -> file already exists CALL DIE ; .. push up some daisies ROPEN45: MOV AH, 3CH ; ah = create function code MOV CL, RSTATTR ; cx = original attributes XOR CH,CH ; .. upper byte off INT 21H ; issue DOS call JNC ROPEN50 ; if no problems, continue MOV DX, OFFSET NOCREATE ; dx -> create error message CALL DIE ; .. go deep six ROPEN50: MOV OHANDLE, AX ; save the file handle MOV DX, OFFSET RESTORING ; dx -> restore message MOV AH, 09H ; ah = print ascii$ INT 21H ; .. tell the user RET ; return to caller ROPEN ENDP ; --------------------------------------------------------------------------- ; RFILE - restore file ; --------------------------------------------------------------------------- RFILE PROC CALL NEXTFILE ; create a file name RFILE10: MOV DX, OFFSET FLOPDRV ; dx -> file name MOV AX, 3D00H ; al = open for read INT 21H ; .. ask DOS to do it. JNC RFILE20 ; ok .. continue RFILE15: MOV DX, OFFSET WRONGDISK ; dx -> wrong disk message CALL HITKEY ; .. display and wait JMP RFILE10 ; .. and try again RFILE20: MOV IHANDLE, AX ; save file handle MOV BX, AX ; bx = handle MOV AH, 03FH ; ah = read file MOV CX, RST_LEN ; cx = len to read MOV DX, OFFSET BUFFER ; dx -> buffer to read INT 21H ; read a buffer JC RFILE35 ; tell 'em we cant read it MOV SI, DX ; si -> buffer MOV DI, OFFSET RSTLAST ; di -> our header MOVSB ; move last flag, setup for compare MOV CX, RST_LEN-1 ; cx = bytes to check REPE CMPSB ; q. headers the same? JE RFILE30 ; a. yes .. continue MOV AH, 3EH ; ah = close file INT 21H ; close output file JMP RFILE15 ; tell 'em RFILE30: MOV AH, 03FH ; ah = read file MOV BX, IHANDLE ; bx = handle of file to read MOV CX, BUFLEN ; cx = amount to read MOV DX, OFFSET BUFFER ; dx -> buffer INT 21H ; read, please JNC RFILE40 ; if no error .. continue RFILE35: MOV DX, OFFSET RDERROR ; dx -> read error message CALL DIE ; ..and die gracefully RFILE40: MOV CX, AX ; cx = bytes to write JCXZ RFILE80 ; if finished .. exit loop MOV AH, 40H ; ax = write MOV BX, OHANDLE ; bx = output file handle INT 21H ; write a buffer JC RFILE50 ; error .. die CMP AX, CX ; q. able to write it? JE RFILE30 ; a. no .. tell 'em MOV DI, OFFSET NOROOM ; di -> wontfit msg JMP SHORT RFILE60 ; ..and exit gracefully RFILE50: MOV DI, OFFSET WRTERROR ; di -> write error message RFILE60: MOV AH, 41H ; ah = delete function MOV DX, OFFSET ROPENFILE ; dx -> filename INT 21H ; issue DOS call MOV DX, DI ; dx -> error message to give CALL DIE ; ..make my day, punk! RFILE80: MOV AH, 3EH ; ah = close file INT 21H ; close output file CMP RSTLAST, 0 ; q. end of file JNE RFILE90 ; a. no .. continue MOV DX, OFFSET NEXTDISK ; dx -> next disk message CALL HITKEY ; display message and wait JMP RFILE ; .. get next file RFILE90: RET ; else .. return to caller RFILE ENDP ; --------------------------------------------------------------------------- ; NEXTFILE - Build next filename ; --------------------------------------------------------------------------- NEXTFILE PROC MOV AX, DESTNBR ; ax = current count AAA ; ax = almost ascii nbr OR AX, 3030H ; ax = ascii values XCHG AL, AH ; swap bytes for store MOV BX, DESTEXT ; bx -> 2nd char of extension MOV [BX], AX ; store rest of extension MOV WORD PTR DISKNO, AX ; .. and in message INC DESTNBR ; increment for next time RET ; ..and return to caller NEXTFILE ENDP ; --------------------------------------------------------------------------- ; HITKEY - Allow user to change diskettes; dx -> first message ; --------------------------------------------------------------------------- HITKEY PROC MOV AH, 9H ; ah = print string INT 21H ; .. call dos to print message MOV DX, OFFSET HITANYKEY ; dx -> prompt INT 21H ; issue prompt message MOV AX, 0C08H ; ax = clear buffer, wait for key INT 21H ; issue DOS call OR AL, AL ; q. function key hit? JNZ HITKEY90 ; a. no .. exit MOV AH, 08H ; ah = wait for key INT 21H ; issue DOS call HITKEY90: RET HITKEY ENDP ; --------------------------------------------------------------------------- ; PARMS - Parses the command line ; --------------------------------------------------------------------------- PARMS PROC CALL UPCASE ; upper case the parm area MOV SI, 81H ; si -> parms area PARMS10: LODSB ; get parameter character CMP AL, 0DH ; q. end of line? JE PARMS50 ; a. yes .. exit CMP AL, " " ; q. blank? JNA PARMS10 ; a. yes .. skip CALL ARGCHK ; set the argument JC PARMSERR ; .. die on an error PARMS30: LODSB ; get next character CMP AL, 0DH ; q. end of line? JE PARMS50 ; a. yes .. process CMP AL, " " ; q. end of PARMS? JA PARMS30 ; a. no .. next char MOV BYTE PTR [SI-1], 0 ; end the parameter JMP PARMS10 ; .. look for next PARMS50: MOV BYTE PTR [SI-1], 0 ; end the parameter CMP ARG, 0 ; q. PARMS 1 available? JNE PARMS60 ; a. no .. error CMP RSTFLAG, 0 ; q. restoring? JE PARMSERR ; a. no .. error MOV ARG, OFFSET CURRDIR ; arg -> current directory PARMS60: CMP FLOPDRV, 0 ; q. Drive given? JE PARMSERR ; a. no .. error also RET ; .. else .. return to caller PARMSERR: MOV DX, OFFSET FORMAT ; dx -> format message MOV AH, 09H ; ah = print ascii$ INT 21H ; hey DOS .. print it! MOV DX, OFFSET RSFORM ; dx -> restore format CMP RSTFLAG, 0 ; q. restore? JNZ PARMSERR1 ; a. yes .. die now MOV DX, OFFSET SPFORM ; dx -> slice format PARMSERR1: CALL DIE ; .. play taps PARMS ENDP ; --------------------------------------------------------------------------- ; ARGCHK - Setup pointers to command line args; si -> 2nd char in arg ; Exit: ARG or FLOPDRV filled in; Carry set if > 2 args ; --------------------------------------------------------------------------- ARGCHK PROC LEA BX, [SI-1] ; bx -> argument CMP RSTFLAG, 0 ; q. restoring? JE ARG05 ; a. no .. continue CMP FLOPDRV, 0 ; q. drive filled in? JE ARG20 ; a. no .. fill it in ARG05: CMP ARG, 0 ; q. ARG filled in? JNE ARG10 ; a. yes .. check 2 MOV ARG, BX ; save ARG pointer JMP SHORT ARG90 ; .. exit ok! ARG10: CMP FLOPDRV, 0 ; q. drive filled in? JE ARG20 ; a. no .. fill it in STC ; else .. error RET ; .. and return to caller ARG20: MOV FLOPDRV, AL ; save drive MOV SPLICEDRV, AL ; .. in file and program names MOV BL, AL ; bl = drive letter SUB BL, "@" ; bl = drive number MOV AX, 4408H ; ax = ioctl, removable? INT 21H ; issue DOS call OR AL, AL ; q. removable media drive? JZ ARG90 ; a. yes .. return MOV DX, OFFSET DRVNR ; dx -> error message CALL DIE ; issue non-removable message ARG90: CLC ; show no error RET ; return to caller ARGCHK ENDP ; --------------------------------------------------------------------------- ; UPCASE - Convert command line arguments to uppercase ; --------------------------------------------------------------------------- UPCASE PROC PUSH SI ; save caller regs PUSH DI MOV SI, 81H ; si -> start of parm area MOV DI, SI ; .. same for di CLD ; .. assure ascending UPCASE10: LODSB ; al = char CMP AL, 0DH ; q. end of line? JE UPCASE90 ; a. yes .. end of line! CMP AL, "a" ; q. is it below 'a'? JB UPCASE20 ; a. yes .. continue CMP AL, "z" ; q. is it above 'z'? JA UPCASE20 ; a. yes .. continue SUB AL, 20H ; set to upper case UPCASE20: STOSB ; save the byte JMP UPCASE10 ; .. and continue UPCASE90: POP DI ; restore caller regs POP SI RET ; .. and return to caller UPCASE ENDP ; --------------------------------------------------------------------------- ; DIE - Display an error message and return to DOS; dx -> ascii$ error msg ; --------------------------------------------------------------------------- DIE PROC MOV AH, 9H ; ah = print string INT 21H ; .. call dos to print error MOV BX, IHANDLE ; bx = input file handle OR BX, BX ; q. file opened? JZ DIE90 ; a. no .. try output file MOV AH, 3EH ; ah = close file INT 21H ; .. ask DOS to do it DIE90: MOV BX, OHANDLE ; bx = output file handle OR BX, BX ; q. file opened? JZ DIE95 ; a. no .. just exit MOV AH, 3EH ; ah = close file INT 21H ; .. ask DOS to do it DIE95: MOV AX, 4C00H ; ax = exit INT 21H ; .. terminate routine DIE ENDP RESTLIMIT EQU $ ; only need up to here ; --------------------------------------------------------------------------- ; Slice only areas and messages ; --------------------------------------------------------------------------- SPFORM DB "SLICE [d:\path\]filename[.ext] " DB " d:",0DH,0AH,0AH,"$" ZEROLEN DB "Input file empty",0DH,0AH,"$" NOCOM DB "Program won't fit",0DH,0AH,"$" SPLICEDRV DB "x:\" SPLICE DB "SPLICE.COM",0 ; --------------------------------------------------------------------------- ; OPEN - Opens next file to process; Carry indicates file would not open. ; --------------------------------------------------------------------------- OPEN PROC MOV DX, ARG ; dx -> file name MOV AX, 3D00H ; al = open for read INT 21H ; .. ask DOS to do it. JC OPEN05 ; ok .. continue MOV IHANDLE, AX ; save file handle MOV AH, 4EH ; ah = find first MOV DX, ARG ; dx -> file to find XOR CX, CX ; cx = search attribute INT 21H ; q. find first file ok? JNC OPEN10 ; a. yes .. continue OPEN05: MOV DX, OFFSET FILENF ; dx -> file not found CALL DIE ; .. gasp your final breath OPEN10: MOV AX, DS:DTA_LSIZ ; ax = lsw of size OR AX, DS:DTA_HSIZ ; q. any data? JNZ OPEN90 ; a. yes ..continue MOV DX, OFFSET ZEROLEN ; dx -> file contains no data CALL DIE ; .. dearly beloved ... OPEN90: RET OPEN ENDP ; --------------------------------------------------------------------------- ; SAVE - Handle building slice files on destination ; --------------------------------------------------------------------------- SAVE PROC CALL BLD_RESTORE ; build restore program SAVE10: MOV AH, 03FH ; ah = read file MOV BX, IHANDLE ; bx = handle of file to read MOV CX, BUFLEN ; cx = amount to read MOV DX, OFFSET BUFFER ; dx -> buffer INT 21H ; read, please JNC SAVE20 ; if no error .. continue MOV DX, OFFSET RDERROR ; dx -> read error message CALL DIE ; ..and die gracefully SAVE20: CALL WRITE ; ..and write out a buffer full JC SAVE90 ; if finished .. exit loop JMP SAVE10 ; else .. get next buffer SAVE90: RET ; return to caller SAVE ENDP ; --------------------------------------------------------------------------- ; BLD_RESTORE - Build the restore program ; --------------------------------------------------------------------------- BLD_RESTORE PROC MOV AH, 2AH ; ah = get date function call INT 21H ; issue DOS call MOV WORD PTR RSTSDTE, CX ; save year MOV WORD PTR RSTSDTE+2, DX ; ..and month and day MOV AH, 2CH ; ah = get time function call INT 21H ; issue DOS call MOV WORD PTR RSTSTME, CX ; save hours and minutes MOV WORD PTR RSTSTME+2, DX ; ..and seconds and hundredths MOV SI, OFFSET DTA_ATTR ; si -> source string MOV DI, OFFSET RSTATTR ; di -> save area MOV CX, RST_FFLEN ; cx = length to move REP MOVSB ; copy string MOV DI, OFFSET HEADER_MSG ; di -> program name MOV SI, OFFSET SPLICE ; si -> restore program name MOV CX, 7 ; cx = length REP MOVSB ; .. setup program name MOV SI, OFFSET DTA_NAME ; si -> source file name MOV DI, OFFSET DESTFILE ; di -> work file name MOV CX, 8 ; cx = length to move BLD_REST10: LODSB ; al = char from filename CMP AL, "." ; q. end of filename? JE BLD_REST30 ; a. yes .. exit loop OR AL, AL ; q. end of string? JZ BLD_REST20 ; a. yes .. exit loop STOSB ; save character LOOP BLD_REST10 ; ..and loop till end of string BLD_REST20: MOV AL, "." ; assure file separator char BLD_REST30: STOSB ; save the separator MOV DESTEXT, DI ; save pointer to file extension CMP BYTE PTR [SI-1], "." ; q. was extension found? JNE BLD_REST32 ; a. no .. allow default LODSB ; get 1st char after extenstion MOV DESTEXTC, AL ; ..and save for later BLD_REST32: MOV RSTFLAG, 1 ; set restore flag MOV AL, DESTEXTC ; al = 1st char of extension MOV DI, DESTEXT ; di -> position in filename STOSB ; save 1st character MOV DESTEXT, DI ; save pointer to 2nd char BLD_REST35: MOV DX, OFFSET SPLICEDRV ; dx -> SPLICE program name CALL CREATE ; create the new file PUSH WORD PTR FLOPDRV ; save drive parameter PUSH ARG ; .. and ARG MOV FLOPDRV, 0 ; zero .. MOV ARG, 0 ; .. them out MOV AH, 40H ; ah = write function code MOV CX, OFFSET RESTLIMIT ; cx = length to move MOV DX, OFFSET START ; dx -> start of program SUB CX, DX ; .. forget the PSP INT 21H ; issue DOS call POP ARG ; restore .. POP WORD PTR FLOPDRV ; .. parameters JC BLD_REST40 ; if ok, continue CMP AX, CX ; q. all of pgm get out? JE BLD_REST50 ; a. yes .. continue BLD_REST40: MOV AH, 3EH ; ah = close function INT 21H ; close file CALL DELETE ; delete output file MOV DX, OFFSET NOCOM ; dx -> no room at the inn CALL HITKEY ; ..issue message JMP BLD_REST35 ; ..and try with a new diskette BLD_REST50: MOV AH, 3EH ; ah = close file INT 21H ; .. ask DOS to do it RET ; return to caller BLD_RESTORE ENDP ; --------------------------------------------------------------------------- ; WRITE - Write a file segment; ax = nbr of bytes to write (0 if EOF) ; Exit: Carry set if EOF processing complete ; --------------------------------------------------------------------------- WRITE PROC MOV BX, OHANDLE ; bx = handle number MOV CX, AX ; q. anything to write? JCXZ WRITE50 ; a. no .. EOF request MOV DX, OFFSET BUFFER ; dx -> start of buffer OR BX, BX ; q. handle open? JNZ WRITE40 ; a. yes .. continue WRITE05: PUSH CX ; save length PUSH DX ; ..and buffer address CALL NEXTFILE ; build extension for next file WRITE10: MOV DX, OFFSET FLOPDRV ; dx -> file to create CALL CREATE ; open new file MOV OHANDLE, BX ; save file handle MOV CX, RST_LEN ; cx = length of header CALL HOWMUCH ; update remaining disk space MOV AH, 40H ; ah = write file function MOV DX, OFFSET RSTLAST ; dx -> our file header INT 21H ; issue DOS call JNC WRITE20 ; if no error .. continue MOV DX, OFFSET WRTERROR ; dx -> error message CALL DIE ; ..then display and die WRITE20: CMP AX, CX ; q. write out all of header? JE WRITE30 ; a. yes .. continue MOV AH, 3EH ; ah = close function INT 21H ; issue DOS call CALL DELETE ; delete new file MOV DX, OFFSET NOROOM ; dx -> next disk message CALL HITKEY ; issue message and wait JMP WRITE10 ; ..try to get next file WRITE30: POP DX ; restore registers POP CX ; WRITE40: CALL HOWMUCH ; get how much to write MOV AH, 40H ; ah = write file INT 21H ; issue DOS call JNC WRITE45 ; die on any error MOV DX, OFFSET WRTERROR ; dx -> general error msg CALL DIE ; issue msg and terminate WRITE45: ADD DX, AX ; dx -> next buffer address MOV CX, DI ; cx = remainder of bytes to write JCXZ WRITE48 ; if no more, exit PUSH DX ; save buffer address MOV AH, 3EH ; ah = close function INT 21H ; issue DOS call MOV DX, OFFSET NEXTDISK ; dx -> next disk message CALL HITKEY ; display message and wait POP DX ; .. restore buffer address JMP WRITE05 ; ..then get next file WRITE48: CLC ; clear carry for caller RET ; ..and return WRITE50: OR BX, BX ; q. handle open? JZ WRITE60 ; a. no .. continue MOV AX, 4200H ; ah = position file XOR CX, CX ; cx = file position XOR DX, DX ; dx = msb of file position INT 21H ; position to top of file MOV RSTLAST, 1 ; set flag MOV AH, 40H ; ah = write function MOV CX, 1 ; cx = length MOV DX, OFFSET RSTLAST ; dx -> buffer INT 21H ; write eof marker in header MOV AH, 3EH ; ah = close function INT 21H ; issue DOS call WRITE60: STC ; set carry flag RET ; ..and return to caller WRITE ENDP ; --------------------------------------------------------------------------- ; HOWMUCH - Calculate how much to write; cx = requested amount to write ; Exit: cx = nbr of bytes which will fit ; di = remainder ; --------------------------------------------------------------------------- HOWMUCH PROC PUSH DX ; save registers MOV AX, WORD PTR AVAIL ; get howmuch is available MOV DX, WORD PTR AVAIL+2 ; . . . . MOV DI, 0 ; assume everything will fit OR DX, DX ; q. more than 64k? JNZ HOWMUCH80 ; a. no .. must be less than 64k CMP CX, AX ; q. enough room left? JNA HOWMUCH80 ; a. yes .. use it all MOV DI, CX ; di = nbr requested SUB DI, AX ; di = remainder MOV CX, AX ; cx = nbr to write HOWMUCH80: SUB AX, CX ; ax = new available SBB DX, 0 ; dx:ax = new available MOV WORD PTR AVAIL, AX ; store for later MOV WORD PTR AVAIL+2, DX ; . . . . HOWMUCH90: POP DX ; restore registers RET ; ..and return HOWMUCH ENDP ; --------------------------------------------------------------------------- ; CREATE - Create new file; dx -> file to open ; Exit: bx = handle of opened file ; --------------------------------------------------------------------------- CREATE PROC MOV BP, DX ; save file name pointer CREATE10: MOV AH, 36H ; ah = get drive info MOV DL, FLOPDRV ; dl = drive letter SUB DL, "@" ; dl = drive number INT 21H ; get free space CMP AX, -1 ; q. drive ok? JE CREATE15 ; a. no .. next disk OR BX, BX ; q. any clusters available? JNZ CREATE18 ; a. yes .. build new file CREATE15: MOV DX, OFFSET NOROOM ; dx -> no room at inn message CALL HITKEY ; get new diskette JMP CREATE10 ; ..try again CREATE18: MUL BX ; dx:ax = nbr of sectors available MUL CX ; dx:ax = nbr of bytes available MOV WORD PTR AVAIL, AX ; store howmuch is available MOV WORD PTR AVAIL+2, DX ; . . . . MOV AH, 4EH ; ah = find first function code MOV CX, 0FFH ; cx = any attributes MOV DX, BP ; dx -> filename INT 21H ; issue DOS call JC CREATE20 ; if not available, create it MOV DX, OFFSET FILEFND ; dx -> file found message CALL HITKEY ; let user change diskette JMP CREATE10 ; ..then try again CREATE20: MOV AH, 3CH ; ah = create function code XOR CX, CX ; cx = no (special) attributes INT 21H ; issue DOS call JNC CREATE90 ; if problems, exit MOV DX, OFFSET NOCREATE ; dx -> create error message CALL DIE ; ..and die CREATE90: MOV BX, AX ; bx = handle RET ; ..and return to caller CREATE ENDP ; --------------------------------------------------------------------------- ; DELETE - Delete a file ; --------------------------------------------------------------------------- DELETE PROC MOV AH, 41H ; ah = delete function MOV DX, OFFSET FLOPDRV ; dx -> filename INT 21H ; issue DOS call RET ; ..and return DELETE ENDP ; --------------------------------------------------------------------------- ; Uninitialized data areas ; --------------------------------------------------------------------------- UDATA EQU $ ; start of unitialized data ROPENFILE EQU BYTE PTR UDATA ; word area for ropen AVAIL EQU DWORD PTR ROPENFILE+65 ; available output space BUFFER EQU BYTE PTR AVAIL+4 ; file buffer BUFLEN EQU 32*1024 ; length of buffer CSEG ENDS ; end of code segment END START