; a program to receive disk files from a remote computer ; cpm equ 0 prtmsg equ 9 open equ 15 close equ 16 write equ 21 create equ 22 setdma equ 26 sys equ 0005h fcb equ 005ch bios equ 0e800h pfm equ 0f000h const equ bios+6 conin equ bios+9 conout equ bios+12 siost equ pfm+18 sioin equ pfm+21 sioout equ pfm+24 cr equ 0dh lf equ 0ah dollar equ 24h ctlq equ 11h ctls equ 13h ctlz equ 1ah ; org 100h start lxi sp,stack lxi d,fcb mvi c,open call sys cpi 4 jnc make ; check if file exists lxi d,exists ; file already exist mvi c,prtmsg call sys jmp cpm ; make lxi d,fcb ; file does not exist mvi c,create call sys cpi 4 jc setpt ; check if space on disk lxi d,cannot ; no space left mvi c,prtmsg call sys jmp cpm ; setpt lxi h,buffer ; OK to write file mvi b,0 push b ; save character count push h ; save buffer address pop d push d mvi c,setdma call sys lxi d,rdcom ; prompt for read command mvi c,prtmsg call sys comand call conin ; get input characters and cpi cr ; loop until carriage return jz com1 push psw mov c,a call conout ; echo characters to console pop psw call sioout ; and send to remote computer jmp comand com1 mvi c,cr ; echo carriage return and call conout mvi c,lf ; line feed call conout mvi a,cr ; send carriage return and call sioout strd call sioin cpi lf ; wait for echo of line feed jnz strd ; ; read file from remote computer ; firstr call siost ; this part of the program jz firstr ; ignores a carriage return call sioin ; if it is the first cpi cr ; character received jnz read0 read call const ; any character typed on keyboard jnz endrd ; will end program call siost ; check if character from SIO jz read ; and loop if not call sioin ; get character read0 push psw mov c,a call conout ; echo it to console pop psw pop h ; and put it in buffer mov m,a inx h pop b inr b mov a,b cpi 128 ; check for full buffer jnz read2 mvi a,ctls ; send control-S if full call sioout call stall ; wait for last characters lxi d,fcb mvi c,write ; write buffer call sys cpi 0 ; check if write is successful jz restor ; write is OK lxi d,eom mvi c,prtmsg call sys lxi d,fcb mvi c,close call sys jmp cpm ; ; move overflow characters into buffer ; restor lda tmpcnt lxi h,buffer cpi 0 ; check if any overflow jz read1 ; no overflow mov b,a push h lxi h,tmp loop mov c,m ; move characters to buffer inx h shld tmpadd ; save tmp address pop h ; get buffer address mov m,c ; put character in buffer inx h push h ; save buffer address lhld tmpadd ; get tmp address dcr b jnz loop ; loop if any characters left pop h lda tmpcnt ; ; start reading again ; read1 push psw push h mvi a,ctlq ; send control-Q call sioout jmp read ; read2 push b push h jmp read ; ; end read ; remove last two characters (the prompt from the remote ; computer) if possible and flush buffer ; endrd pop h pop b mov a,b cpi 0 jz end1a dcx h dcr b mov a,b cpi 0 jz end1a dcx h dcr b ; ; fill buffer with control z and write buffer ; end1a mvi a,ctlz mov m,a inx h inr b mov a,b cpi 128 ; is buffer full? jnz end1a ; no lxi d,fcb ; yes mvi c,write ; so write buffer call sys cpi 0 jz end2 lxi d,eom mvi c,prtmsg call sys end2 lxi d,endp mvi c,prtmsg call sys lxi d,fcb mvi c,close ; close file call sys jmp cpm ; ; wait routine to get characters sent after control-S ; stall mvi a,0 sta tmpcnt lxi h,tmp shld tmpadd mvi a,40 s1 call t500 push psw call getch pop psw dcr a jnz s1 ret ; ; inner delay loop ; t500 push psw mvi a,255 t500a xthl xthl dcr a jnz t500a pop psw ret ; ; get overflow characters and put in "tmp" ; getch call siost rz call sioin lhld tmpadd mov m,a inx h shld tmpadd mov c,a call conout lda tmpcnt inr a sta tmpcnt ret ; tmpcnt ds 1 tmpadd ds 2 tmp ds 32 cannot db 'cannot create file$' exists db 'file already exists$' rdcom db 'enter file read command $' eom db 'disk out of free space $' endp db 'copy completed$' ds 64 stack ds 1 buffer ds 1 ; end start