;*************************************************** ;* * ;* sample random access program for cp/m 3 * ;* * ;*************************************************** org 100h ;base of tpa ; reboot equ 0000h ;system reboot bdos equ 0005h ;bdos entry point ; coninp equ 1 ;console input function conout equ 2 ;console output function pstring equ 9 ;print string until '$' rstring equ 10 ;read console buffer version equ 12 ;return version number openf equ 15 ;file open function closef equ 16 ;close function makef equ 22 ;make file function readr equ 33 ;read random writer equ 34 ;write random wrtrzf equ 40 ;write random zero fill parsef equ 152 ;parse function ; fcb equ 005ch ;default file control block ranrec equ fcb+33 ;random record position ranovf equ fcb+35 ;high order (overflow) byte buff equ 0080h ;buffer address ; cr equ 0dh ;carriage return lf equ 0ah ;line feed ; ;*************************************************** ;* * ;* load SP, set-up file for random access * ;* * ;*************************************************** lxi sp,stack ; ; version 3.1? mvi c,version call bdos cpi 31h ;version 3.1 or better? jnc versok ; bad version, message and go back lxi d,badver call print jmp reboot ; versok: ; correct version for random access mvi c,openf ;open default fcb rdname: lda fcb+1 cpi ' ' jnz opfile lxi d,entmsg call print call parse jmp versok opfile: lxi d,fcb call bdos inr a ;err 255 becomes zero jnz ready ; ; cannot open file, so create it mvi c,makef lxi d,fcb call bdos inr a ;err 255 becomes zero jnz ready ; ; cannot create file, directory full lxi d,nospace call print jmp reboot ;back to ccp ; ;*************************************************** ;* * ;* loop back to "ready" after each command * ;* * ;*************************************************** ; ready: ; file is ready for processing ; call readcom ;read next command shld ranrec ;store input record# lxi h,ranovf mov m,c ;set ranrec high byte cpi 'Q' ;quit? jnz notq ; ; quit processing, close file mvi c,closef lxi d,fcb call bdos inr a ;err 255 becomes 0 jz error ;error message, retry jmp reboot ;back to ccp ; ;*************************************************** ;* * ;* end of quit command, process write * ;* * ;*************************************************** notq: ; not the quit command, random write? cpi 'W' jnz notw ; ; this is a random write, fill buffer until cr lxi d,datmsg call print ;data prompt mvi c,127 ;up to 127 characters lxi h,buff ;destination rloop: ;read next character to buff push b ;save counter push h ;next destination call getchr ;character to a pop h ;restore counter pop b ;restore next to fill cpi cr ;end of line? jz erloop ; not end, store character mov m,a inx h ;next to fill dcr c ;counter goes down jnz rloop ;end of buffer? erloop: ; end of read loop, store 00 mvi m,0 ; ; write the record to selected record number mvi c,writer lxi d,fcb call bdos ora a ;error code zero? jnz error ;message if not jmp ready ;for another record ; ; ;******************************************************** ;* * ;* end of write command, process write random zero fill * ;* * ;******************************************************** notw: ; not the quit command, random write zero fill? cpi 'F' jnz notf ; ; this is a random write, fill buffer until cr lxi d,datmsg call print ;data prompt mvi c,127 ;up to 127 characters lxi h,buff ;destination rloop1: ;read next character to buff push b ;save counter push h ;next destination call getchr ;character to a pop h ;restore counter pop b ;restore next to fill cpi cr ;end of line? jz erloop1 ; not end, store character mov m,a inx h ;next to fill dcr c ;counter goes down jnz rloop1 ;end of buffer? erloop1: ; end of read loop, store 00 mvi m,0 ; ; write the record to selected record number mvi c,wrtrzf lxi d,fcb call bdos ora a ;error code zero? jnz error ;message if not jmp ready ;for another record ; ;*************************************************** ;* * ;* end of write commands, process read * ;* * ;*************************************************** notf: ; not a write command, read record? cpi 'R' jnz error ;skip if not ; ; read random record mvi c,readr lxi d,fcb call bdos ora a ;return code 00? jnz error ; ; read was successful, write to console call crlf ;new line mvi c,128 ;max 128 characters lxi h,buff ;next to get wloop: mov a,m ;next character inx h ;next to get ani 7fh ;mask parity jz ready ;for another command if 00 push b ;save counter push h ;save next to get cpi ' ' ;graphic? cnc putchr ;skip output if not pop h pop b dcr c ;count=count-1 jnz wloop jmp ready ; ;*************************************************** ;* * ;* end of read command, all errors end-up here * ;* * ;*************************************************** ; error: lxi d,errmsg call print jmp ready ; ;*************************************************** ;* * ;* utility subroutines for console i/o * ;* * ;*************************************************** getchr: ;read next console character to a mvi c,coninp call bdos ret ; putchr: ;write character from a to console mvi c,conout mov e,a ;character to send call bdos ;send character ret ; crlf: ;send carriage return line feed mvi a,cr ;carriage return call putchr mvi a,lf ;line feed call putchr ret ; parse: ;read and parse filespec lxi d,conbuf mvi c,rstring call bdos lxi d,pfncb mvi c,parsef call bdos ret ; print: ;print the buffer addressed by de until $ push d call crlf pop d ;new line mvi c,pstring call bdos ;print the string ret ; readcom: ;read the next command line to the conbuf lxi d,prompt call print ;command? mvi c,rstring lxi d,conbuf call bdos ;read command line ; command line is present, scan it mvi c,0 ;start with 00 lxi h,0 ; 0000 lxi d,conlin;command line readc: ldax d ;next command character inx d ;to next command position ora a ;cannot be end of command rz ; not zero, numeric? sui '0' cpi 10 ;carry if numeric jnc endrd ; add-in next digit push psw mov a,c ;value = ahl dad h adc a ;*2 push a ;save value * 2 push h dad h ;*4 adc a dad h ;*8 adc a pop b ;*2 + *8 = *10 dad b pop b adc b pop b ;+digit mov c,b mvi b,0 dad b aci 0 mov c,a jnc readc jmp readcom endrd: ; end of read, restore value in a adi '0' ;command cpi 'a' ;translate case? rc ; lower case, mask lower case bits ani 101$1111b ret ;return with value in chl ; ;*************************************************** ;* * ;* string data area for console messages * ;* * ;*************************************************** badver: db 'sorry, you need cp/m version 3$' nospace: db 'no directory space$' datmsg: db 'type data: $' errmsg: db 'error, try again.$' prompt: db 'next command? $' entmsg: db 'enter filename: $' ; ;*************************************************** ;* * ;* fixed and variable data area * ;* * ;*************************************************** conbuf: db conlen ;length of console buffer consiz: ds 1 ;resulting size after read conlin: ds 32 ;length 32 buffer conlen equ $-consiz ; pfncb: dw conlin dw fcb ; ds 32 ;16 level stack stack: end