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Assembly Source File | 1993-05-10 | 35.3 KB | 777 lines

;******************************************************************** ; ; Program DServ ( Chapter 9 ) ; ; Diskette processing system ( OS independent) ; ; Author: Sopin A.I., Voronegh, 1990 --- 1993. Version 3.0 ; ------ 22/04/93 11:39 ; ; Floppy disks sectors reading/writing ; ; The BIOS disk service (interrupt 13h) is used ; ; Information is output onto the screen in two pages of 256 bytes each ; ;******************************************************************** .model large EXTRN DIAM00 : FAR, DIAM01 : FAR, CLEAR : FAR, DELAY : FAR, COLOR : FAR EXTRN MOVE : FAR, HEXSYM : FAR, SYMIN4 : FAR, INSYM4 : FAR, SYMHEX : FAR ; ; Save registers used PUSHR MACRO REGLST IFB <REGLST> push ax push bx push cx push dx push si push di push ds push es push bp ENDIF IRP REG,<REGLST> push REG ENDM ENDM ; Restore register used POPR MACRO REGLST IFB <REGLST> pop bp pop es pop ds pop di pop si pop dx pop cx pop bx pop ax ENDIF IRP REG,<REGLST> pop REG ENDM ENDM ; Call screen clearing subroutine and set up the screen color CLR MACRO M$,N$,C$ mov ch,M$ mov dh,N$ mov ah,C$ Call Color ENDM ; DIAM0 MACRO TEXT$,OP$,M$,N$,U$,V$ mov TOFF,offset TEXT$ ; address of text string mov OP,OP$ ; operation mode mov M,M$ ; start line for output mov bx,N$ ; mov N,bx ; last line for output mov U,U$ ; don't move cursor mov bx,V$ ; mov V,bx ; lea bx,PARM ; push bx ; address of parameters list for DIAM00 Call DIAM00 ; ENDM ; DIAM1 MACRO TEXT$,OP$,M$,N$,U$,V$ mov TOFF,offset TEXT$ ; address of text string mov OP,OP$ ; operation mode mov M,M$ ; start line for output mov bx,N$ ; mov N,bx ; last line for output mov U,U$ ; don't move cursor mov bx,V$ ; mov V,bx ; lea bx,PARM ; push bx ; address of parameters list for DIAM00 Call DIAM01 ; ENDM ; ; Clear the output buffer (filling with blanks) SPACE MACRO TXT$,L$ mov ax,ds mov es,ax lea di,TXT$ mov cx,L$ cld mov al,' ' rep stosb ENDM ; Output number in hexadecimal representation HEX MACRO L$ ; Local H1 ; mov cx,L$ ; number of bytes H1: mov al,[si] ; Call HEXSYM ; convert: HEX ---> SYM mov DS:[di],ax ; add di,2 ; inc si ; loop H1 ; ENDM ;---------------------------------------------------------- .STACK 256 .DATA ; TEXT0 db ' Disk scanning needed? ? (Y / N ) ',0 TEXT1 db ' Diskette parameters: Cylinders: ?? Heads: 00 ' db 'Sectors: ?? ',0 TEXT2 db ' Reading/modifying disk sectors ' db ' A.I.Sopin, VSU Voronezh 1991 ',0 TEXT3 db ' Drive: A ',0 TEXT4 db ' Drive: A Total: Cylinders: xx Heads: 00 ' db 'Sectors: xx ',0 TEXT5 db ' Address: Cylinder: 00 Head: 00 ' db ' Sector: 01 ',0 Ltext5 EQU $-TEXT5-2 TEXT6 db ' Error while reading sector! AH=xx CC=xx HH=xx SS=xx ' db ' ( press Enter ) ',0 TEXT7 db ' Wrong diskette parameters specified - respecify. ',0 ; TEXT8 DB ' Attention! Disk is being scanned. Please wait. ',0 TEXT9 db ' Error while writing sector! AH=xx CC=xx HH=xx SS=xx ' db ' ( press Enter ) ',0 I1 DB 53,1 ; length =53, offset =1 DB 0,74h ; red letters on grey background DW 0 ; I2 DB 77,0 ; length =77, offset =0 DB 0,74h ; red letters on grey background DW 0 ; TXT0 db 'Displacement ----------------- Hex codes -------------------' db ' ASCII value ',0 TXT25 db ' PgDn -next , PgUp -prev , Esc -exit , F3 -edit sector ' db ', Enter -disk address', 0 Ltxt25 EQU $-TXT25 I25 DB 80,0 ; length of field =80 DB 0,1Eh ; feature + yellow letters on blue DW 0 ; end of list I ; Disp1 db '0000(0000)','0016(0010)','0032(0020)','0048(0030)' db '0064(0040)','0080(0050)','0096(0060)','0112(0070)' db '0128(0080)','0144(0090)','0160(00A0)','0176(00B0)' db '0192(00C0)','0208(00D0)','0224(00E0)','0240(00F0)' Disp2 db '0256(0100)','0272(0110)','0288(0120)','0304(0130)' db '0320(0140)','0336(0150)','0352(0160)','0368(0170)' db '0384(0180)','0400(0190)','0416(01A0)','0432(01B0)' db '0448(01C0)','0464(01D0)','0480(01E0)','0496(01F0)' ; BUFER db 2000 dup (0) ; RDBUF db 512 dup (0) ; ADRBUF dw 0 ; CC0 db 0 ; cylinder number (0...79) HH0 db 0 ; head number (0 or 1) SS0 db 0 ; sector number (1...15) Disk db 0 ; drive number (0-A, 1-B...) Count3 db 0 ; counter of attemts to read NCC0 db 0 ; maximum cylinder number (0 --- 79) NHH0 db 0 ; maximum head number (0 --- 1) NSS0 db 0 ; maximum sector number (1 --- 15) VV dw 0 ; cursor position: CCHHSS NN dw 0 ; line for output=6 (disk addres) MOD0 DB 0 ; indicates that CCHHSS was modified REG DB 0 ; video mode ; ; List of parameters for subroutines DIAM00 and DIAM01 EVEN PARM LABEL WORD ; parameter list (address in stack) OP dw 0 ; operation code M dw 0 ; number of first line N dw 0 ; number of last line TOFF dw 0 ; offset of text string L dw 80 ; length of text string U dw 0 ; row of cursor position (1---25) V dw 0 ; column of cursor position (1---80) Q dw 0 ; accepted row of cursor S dw 0 ; accepted column of cursor W dw 2 dup (0) ; code of interrupt key IOFF dw 0 ; address of screen parameters I dw 80 db 0, 07h ;---------------------------------------------------------- .CODE .Startup mov ah,0Fh ; int 10h ; read current video mode mov REG,al ; save video mode mov IOFF,0 ; format list isn't used CLR 1,24,07h ; CLR 25,25,1Eh ; yellow letters on blue mov IOFF,offset I25 ; DIAM0 TXT25,1,25,25,0,0 ; output prompt string mov IOFF,0 ; ; Output the header and ask for drive letter Addres: DIAM0 TEXT2,1,2,2,0,0 ; DIAM0 TEXT3,3,4,-4,4,12 ; and TEXT3+11,0DFh ; force uppercase mov al,0 ; default drive A cmp TEXT3+11,'A' je M1 ; check for ESC pressed mov al,1 ; use drive B cmp TEXT3+11,'B' ; jne Addres ; invalid drive letter specified M1: mov Disk,al ; drive number cmp byte ptr W,1bh ; Esc ? jne ScanD ; ask for disk scanning jmp Exit ; ;---------------------------------------------------------- ; Ask for disk scanning to determine the diskette characterisics ScanD: DIAM0 TEXT0,3,5,-5,5,32 ; and TEXT0+31,0DFh ; force uppercase cmp byte ptr W,1bh ; Esc ? jne CodeS ; jmp Addres ; CodeS: cmp TEXT0+31,'Y' ; scanning required? je Ready ; cmp TEXT0+31,'N' ; scanning not required? jne ScanD ; bad reply - ask again Call PARMDSK ; jmp Diskadr ; ; Check for drive ready Ready: mov CC0,0 ; cylinder number mov HH0,0 ; head number (0---1) mov SS0,1 ; sector number (1---8) Call SECTOR ; read sector (3 attempts) jnc Attent ; reading successful jmp Error1 ; error message ; Output message about disk scanning (line 5) Attent: mov IOFF,offset I1 ; address of format list DIAM0 TEXT8,1,5,-5,0,0 ; mov IOFF,0 ; format list isn't used ;---------------------------------------------------------- ; Scanning the diskette to dtermine CC, HH, SS ; Determining the number of cyilinders CC ScanCC: mov CC0,0 ; cylinder number mov HH0,0 ; head number (0---1) mov SS0,1 ; sector number (0---8) CyclCC: Call SECTOR ; read sector (3 attempts) jc ScanHH ; sector hasn't been read inc CC0 ; to next cylinder jmp short CyclCC ; ; Determining the number of heads HH ScanHH: mov al,CC0 dec al ; extra cylinder was read mov NCC0,al ; maximum cylinder number mov NHH0,0 ; maximum head number =0 (one side) mov TEXT4+53,'1' ; head number =0 (one side) mov CC0,0 ; cylinder number =0 mov HH0,1 ; head number = 1 (second side) mov SS0,1 ; sector number =1 Call SECTOR ; read sector (3 attempts) jc ScanSS ; sector hasn't been read mov TEXT4+53,'2' ; second side (head =1) mov NHH0,1 ; maximum head number =1 (two sides) ; Determining the number of sectors SS ScanSS: mov CC0,0 ; cylinder number =0 mov HH0,0 ; head number = 1 (first side) mov SS0,1 ; sector number =1 CyclSS: Call SECTOR ; read sector (3 attempts) jc Diskparm ; next sector hasn't been read inc SS0 ; to next cylinder jmp short CyclSS ; ;---------------------------------------------------------- ; Output characteristics of disk read (CC/HH/SS) DiskParm: CLR 5,24,07h ; clear lines 5 --- 24 mov al,SS0 ; dec al ; next number was specified mov NSS0,al ; maximum sector number lea bp,TEXT4+67 ; target for edited value Call INTSYM ; convert number of setors mov al,NCC0 ; maximum cylinder number inc al ; cylinders are counted from 0 lea bp,TEXT4+38 ; target for edited value Call INTSYM ; convert number of cylinders DIAM0 TEXT4,1,4,-4,0,0 ; ;---------------------------------------------------------- ; Ask for cylinder number CC and input that number Diskadr:mov VV,39 ; GetCC: DIAM0 TEXT5,3,5,-5,5,VV ; cmp byte ptr W+1,49h ; PgUp ? je JmpAdr ; to preceeding parameter cmp byte ptr W,1Bh ; Esc ? jne ConvCC ; JmpAdr: jmp Addres ; ; Convert the number of the cylinder CC ConvCC: lea bp,TEXT5+38 ; mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov CC0,al ; jnc ConvHH ; DIAM0 TEXT7,1,6,-6,0,0 ; output error message jmp Diskadr ; repeat input ; Ask for the head number HH (0 or 1) and input that number ConvHH: mov al,CC0 ; lea bp,TEXT5+38 ; target for edited value CC Call INTSYM ; convert INT ---> SYM DIAM0 TEXT5,3,5,-5,5,53 ; cmp byte ptr W+1,49h ; PgUp ? je JmpC ; cmp byte ptr W,1bh ; Esc ? jne ConvH ; JmpC: jmp Diskadr ; repeat asking for CC ; Convert the head number HH (0 or 1) ConvH: lea bp,TEXT5+52 ; mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov HH0,al ; jc Goerr ; cmp al,1 ; head number > 1 requested? jng ConvSS ; DIAM0 TEXT7,1,6,-6,0,0 ; output error message Goerr: jmp ConvHH ; output error message ; Ask for sector number SS and input that number ConvSS: DIAM0 TEXT5,3,5,-5,5,68 ; cmp byte ptr W+1,49h ; PgUp ? je JmpH ; cmp byte ptr W,0Dh ; Enter ? je ConvS ; cmp byte ptr W,1Bh ; Esc ? jne ConvS ; JmpD: jmp Diskadr ; ask for cylinder number again JmpH: jmp ConvHH ; ask for head number again ; Convert sector number SS ConvS: lea bp,TEXT5+67 ; mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov SS0,al ; mov Count3,3 ; counter of attempts to read jnc Rdsect ; DIAM0 TEXT7,1,6,-6,0,0 ; output error message jmp ConvSS ; repeat parameters input ;---------------------------------------------------------- ; Read the sector (512 bytes) with the number required Rdsect: Call SECTOR ; read sevtor required jnc P1 ; sector is read succesfully lea si,BUFER ; source lea di,TEXT5 ; target mov cx,Ltext5 ; length of data transferred Call MOVE ; transfer string of addresses jmp Error1 ; ;---------------------------------------------------------- ; Output sector content onto the screen (lines 5---22) ; Editing and output the first page ( 256 bytes) P1: lea si,RDBUF ; source data lea bp,Disp1 ; Call SCREEN ; output first 256 bytes mov BUFER+5,'1' ; page number DIAM1 BUFER,3,5,22,5,39 ; output buffer onto screen lea si,BUFER ; source lea di,TEXT5 ; target mov cx,Ltext5 ; length of data transferred Call MOVE ; transfer string of addresses lea di,RDBUF ; target data Call MODSECT ; checking for sector modification cmp MOD0,1 ; address was modified jne MOD1 ; jmp Rdsect ; output new sector MOD1: Call MODCHS ; process changed values of CC, HH, SS Call TABUL ; changing disk address ; Process keys: Esc, PgDn, PgUp Esc1: cmp byte ptr W,1Bh ; Esc ? je JmpBeg ; cmp byte ptr W+1,51h ; PgDn ? je P2 ; output second part of sector cmp byte ptr W+1,49h ; PgUp ? jne P2 ; Call Back ; read backwards jmp Rdsect ; read sector again JmpBeg: jmp Diskadr ; Editing and output second page (last 256 bytes) P2: lea si,RDBUF+256 ; source data lea bp,Disp2 ; Call SCREEN ; output last 256 bytes mov BUFER+5,'2' ; page number DIAM1 BUFER,3,5,22,5,39 ; output buffer onto screen lea si,BUFER ; source lea di,TEXT5 ; target mov cx,Ltext5 ; length of data transferred Call MOVE ; transfer string of addresses lea di,RDBUF ; target data Call MODSECT ; check for sector mofifying cmp MOD0,1 ; sector was modified? jne MOD2 ; jmp Rdsect ; output new sector MOD2: Call MODCHS ; process changed values of CC, HH, SS Call TABUL ; change disk address ; Process keys: Esc, PgDn, PgUp Esc2: cmp byte ptr W,1Bh ; Esc ? je JmpBeg ; back to beginning cmp byte ptr W+1,49h ; PgUp ? jne PgDn2 ; jmp P1 ; PgDn2: cmp byte ptr W+1,51h ; PgDn ? je Next2 ; jmp P2 ; Next2: Call NEXT ; jmp Rdsect ; to processing next sector ;---------------------------------------------------------- ; Finish of the program Exit: mov ah,0 ; function 0 - set video mode mov al,REG ; restore original video mode int 10h ; BIOS video service call mov ax,4C00h ; function 4Ch - terminate process int 21h ; MS-DOS service call ;---------------------------------------------------------- ; ; Read sector (512 bytes) with the address specified ; ;---------------------------------------------------------- SECTOR PROC NEAR mov Count3,3 ; counter of attempts to read Read3: xor ah,ah ; function 00h - reset controller int 13h ; BIOS disk service call jc RetS ; exit if error (error code in AH) mov ax,ds ; mov es,ax ; ES points to data segment lea bx,RDBUF ; address of read buffer mov ch,CC0 ; cylinder number mov cl,SS0 ; sector number (1---8) mov dh,HH0 ; head number (0---1) mov dl,Disk ; disk drive (0 -A, 1 -B...) mov al,1 ; number of sectors to read mov ah,2 ; function 02h - read sectors int 13h ; BIOS disk service call jnc RetS ; sector was read successfully dec Count3 ; decrement counter of attempts jg Read3 ; try to read sector again RetS: RET ; SECTOR ENDP ; Output error message (error while reading sector in line 6) Error1: mov al,ah ; error code Call HEXSYM ; convert HEX ---> SYM mov word ptr TEXT6+33,ax ; transfer error code mov al,CC0 ; lea bp,TEXT6+40 ; target for edited value Call INTSYM ; convert INT ---> SYM mov al,HH0 ; lea bp,TEXT6+47 ; target for edited value Call INTSYM ; convert INT ---> SYM mov al,SS0 ; lea bp,TEXT6+54 ; target for edited value Call INTSYM ; convert INT ---> SYM mov IOFF,offset I2 ; DIAM0 TEXT6,2,6,-6,0,0 ; output message mov IOFF,0 ; CLR 5,24,07h ; clear screen jmp Addres ; ask for disk address again ;---------------------------------------------------------- ; ; Writing modified sector ; ; Is performed when the cursor is within the data area ; ; and the F3 key has been pressed ; ; DI - address of sector buffer in data segment ; ;---------------------------------------------------------- MODSECT PROC NEAR mov MOD0,0 ; clear modification indicator cmp byte ptr W+1,3Dh ; F3 ? jne RetModS ; no, exit cmp byte ptr Q,7 ; cursor in data area ? jl RetModS ; no, exit cmp byte ptr Q,22 ; cursor in data area ? jg RetModS ; no, exit cmp byte ptr S,14 ; cursor in data area ? jl RetModS ; no, exit cmp byte ptr S,72 ; cursor in data area ? jng C0 ; yes RetModS: RETN ; ; Transfer modified data into the sector buffer C0: PUSHR ; mov MOD0,1 ; modification indicator mov ax,ds ; mov es,ax ; ES points to data segment lea si,BUFER+173 ; address of screen string beginning mov ADRBUF,si ; save address of string mov dx,16 ; number of lines output ; Outward cycle (16 lines) C1: mov cx,16 ; number of elements line C2: mov ax,[si] ; nested cycle starts here Call SYMHEX ; convert: SYM ---> HEX mov [di],al ; transfer hexadecimal value add si,3 ; address of next two bytes inc di ; address of next byte in sector loop C2 ; next step of nested cycle ; Modify parameters of the outward cycle (to next line) mov si,ADRBUF ; add si,80 ; address of next string mov ADRBUF,si ; save address of string dec dx ; number of strings left jnz C1 ; to beginning of outward cycle ; Writing the modified sector mov Count3,3 ; counter of attempts to write Write3: xor ah,ah ; function 00h - reset controller int 13h ; BIOS disk service call mov ax,ds ; mov es,ax ; ES points to data segment lea bx,RDBUF ; address of buffer for writing ES:BX mov ch,CC0 ; cylinder number mov cl,SS0 ; sector number (1---8) mov dh,HH0 ; head number (0---1) mov dl,Disk ; disk drive (0 -A, 1 -B...) mov al,1 ; number of sectors to write mov ah,3 ; function 03h - write sectors int 13h ; BIOS disk service call jnc Retwr ; sector has been written dec Count3 ; decrease number of attempts jg Write3 ; try to write again jmp short Error2 ; error while writing sector Retwr: POPR ; RETN ; ; Output message "error while writing sector" (line =6) Error2: mov al,ah ; error code Call HEXSYM ; convert HEX ---> SYM mov word ptr TEXT9+33,ax ; transfer eror code mov al,CC0 ; lea bp,TEXT9+40 ; target for edited data Call INTSYM ; convert INT ---> SYM mov al,HH0 ; lea bp,TEXT9+47 ; target for edited data Call INTSYM ; convert INT ---> SYM mov al,SS0 ; lea bp,TEXT9+54 ; target for edited data Call INTSYM ; convert INT ---> SYM mov IOFF,offset I2 ; DIAM0 TEXT9,2,6,-6,0,0 ; output message mov IOFF,0 ; CLR 6,6,07h ; clear string POPR ; RETN ; MODSECT ENDP ;---------------------------------------------------------- ; ; To process the next sector ; ;---------------------------------------------------------- ; Increase the sector number by 1 NEXT PROC NEAR mov al,SS0 ; preceeding sector number inc al ; number of next sector cmp al,NSS0 ; to other side? jg ModHH ; mov SS0,al ; transfer number of next sector jmp RetM ; to processing next sector ; Increase the head number by 1 ModHH: mov SS0,1 ; first sector of next cylinder mov al,HH0 ; number of head (side) processed inc al ; number of next head cmp al,NHH0 ; to next cylinder? jg ModCC ; mov HH0,al ; transfer number of next head jmp RetM ; to processing next sector ; Increase the cylinder number by 1 ModCC: mov SS0,1 ; first sector of next cylinder mov HH0,0 ; initial head number =1 mov al,CC0 ; number of preceeding cylinder inc al ; number of next cylinder cmp al,NCC0 ; all cylinders processed ? jg RetM ; yes, not move mov CC0,al ; transfer number of next cylinder RetM: RETN NEXT ENDP ;---------------------------------------------------------- ; ; Reading disk sectors backwards ; ;---------------------------------------------------------- BACK PROC NEAR ; decreasing sector number by 1 DecSS: mov al,SS0 ; sector number dec al ; preceeding sector number cmp al,1 ; to preceeding cylinder? jl DecHH ; mov SS0,al ; transfer preceeding sector number jmp Retb ; to processing preceeding sector ; decreasing head number by 1 DecHH: mov SS0,1 ; initial sector number =1 mov al,HH0 ; number of current head dec al ; number of preceeding head jl DecCC ; mov HH0,al ; transfer number of preceeding head jmp Retb ; to processing preceeding sector ; decreasing cylinder number by 1 DecCC: mov SS0,1 ; first sector of preceeding cylinder mov HH0,0 ; initial head number =0 mov al,CC0 ; number of current cylinder dec al ; number of preceeding cylinder jl Retb ; mov CC0,al ; transfer number of prec. cylinder Retb: RETN BACK ENDP ;---------------------------------------------------------- ; ; Subroutine for converting an integer number into character string ; ; AL - source number (is converted to a word) ; ; BP - address of output character string ; ;---------------------------------------------------------- INTSYM PROC NEAR cbw ; convert byte to word xor dx,dx ; high part =0 mov si,2 ; number of character in result Call INSYM4 ; convert integer cmp byte ptr DS:[bp],' ' ; suppressed zero present? jne Retint ; mov byte ptr DS:[bp],'0' ; put leading zero Retint: RETN INTSYM ENDP ;---------------------------------------------------------- ; ; Subroutine for creating the display buffer (256 bytes) ; ; SI - address of sector buffer ; ; BP - address of Displacement Table ; ;---------------------------------------------------------- SCREEN PROC NEAR PUSHR ; save all registers PUSHR <si,bp> ; SPACE BUFER,2000 ; clear screen buffer lea si,TEXT5 ; source lea di,BUFER ; target mov cx,Ltext5 ; length of data transferred Call MOVE ; transfer string of addresses ; Create disk addresses (line =5) mov al,CC0 ; address of cylinder lea bp,BUFER+38 ; target for edited value Call INTSYM ; convert INT --- SYM mov al,HH0 ; address of head lea bp,BUFER+52 ; target for edited value Call INTSYM ; convert INT --- SYM mov al,SS0 ; number of sector lea bp,BUFER+67 ; target for edited value Call INTSYM ; convert INT --- SYM ; Create header (line 6) lea si,TXT0 ; source lea di,BUFER+80 ; target mov cx,80 ; length of data transferred Call MOVE ; transfer header POPR <bp,si> ; lea di,BUFER+160 ; address of screen string beginning mov ADRBUF,di ; save address of string mov dx,16 ; number of lines on screen ; Outward cycle (16 lines) S0: PUSHR <si,di> ; inc di ; target mov si,bp ; source mov cx,10 ; length of data transferred Call MOVE ; transfer margins POPR <di,si> ; mov cx,16 ; number of characters in line mov bx,di ; save address of string ; Nested cycle (16 bytes) S1: mov al,[si] ; start of nested cycle Call HEXSYM ; convert: HEX ---> SYM mov DS:[di+13],ax ; transfer hexadecimal value mov al,[si] ; ASCII character cmp al,1bh ; Esc ? jg S2 ; mov al,20h S2: mov [bx+63],al ; transfer ASCII character add di,3 ; address of next pair of byte inc bx ; address of next ASCII character inc si ; address of byte in sector loop S1 ; to repeat of nested cycle ; Modify parameters of the outward cycle (to the next line) mov di,ADRBUF ; add di,80 ; address of next string mov ADRBUF,di ; save address of string add bp,10 ; address of next element dec dx ; number of strings left jnz S0 ; to beginning of outward cycle ; Put edited addresses into the string TEXT5 lea si,BUFER ; source lea di,TEXT5 ; target mov cx,Ltext5 ; length of data transferred Call MOVE ; transfer string of addresses POPR ; RETN ; SCREEN ENDP ;---------------------------------------------------------- ; ; Change the disk address (the Enter key) ; ;---------------------------------------------------------- TABUL PROC NEAR cmp byte ptr W,0Dh ; Enter ? je SS39 ; RETN SS39: pop ax ; restore stack cmp S,39 ; cursor at cylinder position ? je VV53 ; set at the head position and repeat cmp S,41 ; cursor at cylinder position ? ja SS53 ; VV53: jmp ConvHH ; repeat output (cursor at HH) ; Check wheteher the cursor is located in head position (jump to sector) SS53: cmp S,53 ; cursor at head position ? je VV68 ; cmp S,54 ; cursor at head position ? jne SS68 ; VV68: jmp ConvSS ; repeat output (cursor at SS) SS68: jmp Diskadr ; repeat output (cursor at CC) TABUL ENDP ;---------------------------------------------------------- ; ; Subroutine for processing athe sector number ; ;---------------------------------------------------------- MODCHS PROC NEAR lea bp,BUFER+38 ; value of cylinder number CC mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov CC0,al ; new value of cylinder number lea bp,BUFER+52 ; value of head number HH mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov HH0,al ; new value of head number lea bp,BUFER+67 ; value of sector number SS mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov SS0,al ; new value of sector number Retmod: RET MODCHS ENDP ;---------------------------------------------------------- ; ; Ask for diskette parameters (CC, HH, SS) ; ;---------------------------------------------------------- PARMDSK PROC NEAR InpCHS: DIAM0 TEXT1,3,5,-5,5,39 ; lea bp,TEXT1+38 ; value of cylinder number CC mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT dec al ; cylinder number : 0 --- 80 mov NCC0,al ; maximum cylinder number jnc InpHH ; DIAM0 TEXT7,1,6,-6,0,0 ; output error message jmp InpCHS ; repeat input ; InpHH: DIAM0 TEXT1,3,5,-5,5,53 ; lea bp,TEXT1+52 ; value of head number HH mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT dec al ; mov NHH0,al ; maximum head number jnc InpSS DIAM0 TEXT7,1,6,-6,0,0 ; output error message jmp InpHH ; repeat input ; InpSS: DIAM0 TEXT1,3,5,-5,5,68 ; lea bp,TEXT1+67 ; value of sector number SS mov si,2 ; counter of source characters Call SYMIN4 ; convert SYM --- INT mov NSS0,al ; maximum sector number jnc RetCHS DIAM0 TEXT7,1,6,-6,0,0 ; output error message jmp InpSS ; repeat input RetCHS: RET PARMDSK ENDP END