IF NOT lasm .printx * CPXBEE.ASM * ENDIF ;NOT lasm ; KERMIT - (Celtic for "FREE") ; ; This is the CP/M-80 implementation of the Columbia University ; KERMIT file transfer protocol. ; ; Version 4.09 ; ; Copyright June 1981,1982,1983,1984,1985 ; Columbia University ; ; Originally written by Bill Catchings of the Columbia University Center for ; Computing Activities, 612 W. 115th St., New York, NY 10025. ; ; Contributions by Frank da Cruz, Daphne Tzoar, Bernie Eiben, ; Bruce Tanner, Nick Bush, Greg Small, Kimmo Laaksonen, Jeff Damens, and many ; others. ; ; ; ; revision history: ; ; edit 1, 1st September 1990 ; Original version by Russell Lang ; The 'microbee' is designed and manufactured in Australia ; by Microbee Systems Ltd (previously Applied Technology). ; The microprocessor is a Z80 at 3.375MHz. ; The video screen is memory mapped from 0F000h to 0F7FFh, ; with Programmable Characters 80-FF from 0F800h to 0FFFFh. ; The serial and parallel ports are implemented using a Z80 PIO. ; The early model microbees were ROM-Basic computers with up ; to 32k of battery backed RAM. Later models dropped the ; ROM-Basic and added disk drives and CP/M. The disk systems ; include the 56k (64k) APC (5.25" drives), 64k Computer-In-A-Book ; (3.5"), 128k Dynamic (5.25" or 3.5"), 256TC (3.5"). ; ; This version of kermit was developed on a 56k APC. ; It has been tested on 56k, 64k, 128k and 256k Microbees. ; ; The serial port is implemented in software NOT hardware. ; A special transmit routine allows simultaneous receiving ; for all speeds except 75/1200, 1200/75, 4800, 9600. ; The receive routine is interrupt driven with a 2 kbyte buffer. ; The 9600 bit/s speed is marginal on receive - if the transmitter ; is slightly fast (more than about 1%), the serial routine will ; not have enough time to put the character in the buffer before ; the next character arrives. ; ; *** MAIN CODE START *** ; ; ; Keep module name, edit number, and last revision date in memory. sysedt: db 'CPXSYS.ASM (35) 01-Dec-86$' family: db 'CPXBEE.ASM (1) 01-Sep-90$' ; Assembly time message announcing which version we're building .printx * Assembling Microbee Kermit-80 * z80 EQU TRUE ; They all use Z80s defesc EQU ']'-100O ;The default escape character for Microbee vtval EQU 0 ; use default emulation which is adm3a superset ; sysxin: ;continuation of system initialisation code ; set up baud rate lxi h,t300 shld speed xchg call setbaud ; change the interrupt vector so that we intercept rs232 input db 0EDh,57h ;ld a,i ;get old interrupt reg sta oldint mvi a,int ;new value db 0EDh,47h ;ld i,a ret ; return from system-dependent routine ; ; sysexit - System-dependent termination processing ; if we've changed anything, this is our last ; chance to put it back. ; sysexit: lda oldint ;restore old interrupt reg db 0EDh,47h ;ld i,a ret ; ; syscon - System-dependent processing for start ; of CONNECT command. ; syscon: lxi d,conmsg call prtstr ret conmsg: ; Messages printed when entering transparent (CONNECT) mode: db cr,lf,'$' ; ; syscls - system-dependent close routine ; called when exiting transparent session. ; syscls: ret ; ; sysinh - help for system-dependent special functions. ; called in response to ?, after listing ; all the system-independent escape sequences. ; sysinh: lxi d,inhlps ; we got options... call prtstr ; print them. ret ; additional, system-dependent help for transparent mode ; (two-character escape sequences) inhlps: db cr,lf,'B Transmit a BREAK (0.3s)' db cr,lf,'L Transmit a LONG BREAK (1.8s)' db cr,lf,'W Wipe screen clear' db '$' ; sysint - system dependent special functions ; called when transparent escape character has been typed; ; the second character of the sequence is in A (and in B). ; returns:- ; non-skip: sequence has been processed ; skip : sequence was not recognized ; sysint: ani 137O ; convert lower case to upper, for testing... cpi 'B' ; send break ? jz sendbr ; then jump to send break routine cpi 'L' ; long break ? jz longbr ; then jump to long break routine cpi 'W' ; clear screen ? jz clrtop ; then jump to clear screen routine jmp rskp ; take skip return - command not recognized. ; ; Break routines ; longbr: mvi e,180 ; time for long break is 1800 ms jmp setbit sendbr: mvi e,30 ; time for break is 300 ms setbit: in portb ani 0dfh ; mask with tx bit out portb ; ; Now, delay for duration of hangup or break mov a,e ; delay count call delay ; ; Time's up. Put transmitter back in normal state and return. in portb ori 20h ; mask with tx bit out portb ret ; done. ; sysflt - system-dependent filter ; called with character in E. ; if this character should not be printed, return with A = zero. ; preserves bc, de, hl. ; note: ,,, and are always discarded. ; sysflt: mov a,e ; get character for testing ret ; ; sysbye - system-dependent processing for BYE command. ; sysbye: ret ; ; This is the system-dependent command to change the baud rate. ; DE contains the two-byte value from the baud rate table; this ; value is also stored in 'speed'. ; sysspd: call setbaud ret ; ; Speed tables ; (Note that speed tables MUST be in alphabetical order for later ; lookup procedures, and must begin with a value showing the total ; number of entries. The speed help tables are just for us poor ; humans. ; db string length,string,divisor (2 identical bytes or 1 word) ; [Toad Hall] spdtbl: db 11 ;11 entries db 03h,'110$' dw t110 db 04h,'1200$' dw t1200 db 07h,'1200/75$' dw t1275 db 03h,'150$' dw t150 db 04h,'2400$' dw t2400 db 03h,'300$' dw t300 db 04h,'4800$' dw t4800 db 03h,'600$' dw t600 db 02h,'75$' dw t75 db 07h,'75/1200$' dw t7512 db 04h,'9600$' dw t9600 sphtbl: db cr,lf,'75 75/1200 110 150 300 600 1200 1200/75' db ' 2400 4800 9600$' ; ; This is the system-dependent SET PORT command. sysprt: ret prttbl equ 0 ; SET PORT is not supported prhtbl equ 0 ; ; selmdm - select modem port ; selcon - select console port ; selmdm is called before using inpmdm or outmdm; ; selcon is called before using inpcon or outcon. ; preserves BC, DE, HL. ; selmdm: selcon: ret ; ; Get character from console, or return zero. ; result is returned in A. destroys bc, de, hl. ; inpcon: mvi c,dconio ;Direct console I/O BDOS call. mvi e,0FFH ;Input. call BDOS ret ; ; ; Output character in E to the console. ; destroys bc, de, hl ; outcon: mvi c,dconio ;Console output bdos call. call bdos ;Output the char to the console. ret ; ; ; outmdm - output a char from E to the modem. ; the parity bit has been set as necessary. ; returns nonskip; bc, de, hl preserved. outmdm: ; push psw push b push d push h mov a,e lxi h,outm2 ; return address push h lhld txcall pchl ; send to rs232 port outm2: pop h pop d pop b pop psw ret ; ; get character from modem; return zero if none available. ; bc, de, hl preserved. inpmdm: call rsin ; get char if available ret ; return with character in A ; ; flsmdm - flush comm line. ; Modem is selected. ; Currently, just gets characters until none are available. flsmdm: call inpmdm ; Try to get a character ora a ; Got one? jnz flsmdm ; If so, try for another ret ; Receiver is drained. Return. ; ; lptstat - get the printer status. Return a=0 if ok, or 0ffh if not. lptstat: lda pflag ret ; ; outlpt - output character in E to printer ; console is selected. ; preserves de. outlpt: push d ; save DE in either case ana a ; if A = 0 do nothing, jz outlp1 ; [30] if a=0 do nothing mov a,e call parout outlp1: pop d ; restore saved register pair ret ; ; ; Screen manipulation routines ; csrpos - move to row B, column C ; ; csrpos for terminals that use a leadin sequence followed ; by (row + 31.) and (column + 31.) ; csrpos: push b ; save coordinates lxi d,curldn ; get cursor leadin sequence call prtstr ; print it pop h ; restore coordinates mov a,h ; get row adi (' '-1) ; space is row one mov e,a push h call outcon ; output row pop h mov a,l ; get column adi (' '-1) ; space is column one mov e,a jmp outcon ; output it and return ; ; delchr - make delete look like a backspace. Unless delete is a ; printing character, we just need to print a backspace ; (we'll output clrsp afterwards) delchr: lxi d,delstr jmp prtstr ; erase the character at the current cursor position clrspc: mvi e,' ' call outcon mvi e,bs ;get a backspace jmp outcon ; erase the current line clrlin: lxi d,eralin jmp prtstr ; erase the whole screen, and go home clrtop: lxi d,erascr jmp prtstr sysver: db 'Microbee$' outlin: db 1AH,cr,lf,tab,'$' ;(Clear screen, home cursor) erascr: db 1AH,'$' ;Clear screen and go home. eralin: db cr,esc,'T$' ;Clear line. delstr: db bs,'$' ; Adjust for delete curldn: db esc,'=$' ;Cursor lead-in ttab: ;Table start location. ta: db ('K'-100O),'$',0,0 ;Cursor up. tb: db 12O,'$',0,0 ;Cursor down. tc: db ('L'-100O),'$',0,0 ;Cursor right. td: db bs,'$',0,0 ;Cursor left. te: db subt,'$',0,0 ;Clear screen. tf: db '$',0,0,0 ;(can't) Enter graphics mode tg: db '$',0,0,0 ;(can't) Exit graphics mode th: db ('^'-100O),'$',0,0 ;Cursor home. ti: db ('K'-100O),'$',0,0 ;Reverse linefeed. tj: db esc,'Y$',0 ;Clear to end of screen. tk: db esc,'T$',0 ;Clear to end of line. ;Microbee software serial port routines porta equ 0 portb equ 2 ; interrupt vectors ; We change the Z80 Interrupt register to point to these vectors. ; Instead of trying to identify a particular Microbee system, ; we just put vectors here for all systems. ; ; known vectors are: ; 48h : 56k (64k apc) - tested 19-Jun-1990 ; 48k : 64k - tested 01-Sep-1990 ; 50h : dreamdisk (3rd party disk for Microbee) ; e0h : 128k - tested 19-Jun-1990 ; e0h : 256k - tested 01-Sep-1990 org ($ and 0ff00h) + 100h int equ $/256 ; byte for interrupt register dw inta ; printer vector dw intb ; rs232 vector dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb dw inta dw intb ; tables for baud rates t75: db 124,13 ; full delay db 55,7 ; semi delay db 168,255 ; txrx delay dw trout ; address of subroutine to transmit char t7512: db 124,13 ; 75R/1200T db 55,7 db 194,1 ; txout delay dw txout t110: db 129,9 db 55,5 db 5,217 dw trout t150: db 59,7 db 23,4 db 2,158 dw trout t300: db 26,4 db 134,2 db 3,75 dw trout t600: db 139,2 db 191,1 db 2,34 dw trout t1200: db 195,1 db 90,1 db 3,13 dw trout t1275: db 195,1 ; 1200R/75T db 90,1 db 124,13 dw txout t2400: db 94,1 db 40,1 db 2,3 dw trout t4800: db 44,1 db 15,1 db 44,1 dw txout t9600: db 19,1 db 1,1 db 19,1 dw txout ; copy table entries to locations used by serial routines setbaud: lxi h,fulldel mvi b,8 setb2: ldax d mov m,a inx h inx d dcr b jnz setb2 ret ;transmit character in E ; destroys all regs txout: mvi b,ntotal ;total number of bits to send di in portb ;c = portb with tx bit zeroed ani 0dfh mov c,a ora a ;carry=0 (start bit) txout2: mov a,c ; 4T jnc txout4 ;10T skip if space ori 20h ; 3T (average) set mark txout4: out portb ;11T lhld txrxdel ;16T txout6: dcr l ;delay jnz txout6 dcr h jnz txout6 ; 14*L + 14*H + 3584*(H-1) stc ; 4T carry=1 (stop bit) mov a,e ; 4T shift next bit to carry rar ; 4T mov e,a ; 4T dcr b ; 4T jnz txout2 ;10T ;loop = 74T + (delay loop) ei ret ; ;transmit character in E ;simultaneous receive char if necessary trout: mov a,e mvi b,ndata lxi h,0 tro2: rrc ;shift tx char to hl mov c,a mov a,l ral mov l,a mov a,h ral mov h,a mov a,c ;recover dcr b jnz tro2 tro10: mvi b,tqfudge ;adjust char in hl to align with ;tx bit of portb tro12: stc ; pad out mov a,l ral mov l,a mov a,h ral mov h,a dcr b jnz tro12 mvi a,0ffh ;flag to say we are not receiving sta trtemp ;save it mvi d,tqbit ;total number of qtr bits to send in portb ;b = portb with tx bit zeroed ani 0dfh mov b,a mvi e,0 ;we are not receiving yet tro14: in portb ori 8h ;test CTS jz tro14 ;loop till Clear To Send out 09h ;Color Wait OFF di call qbit lda trtemp ;are we receiving ora a jnz tro22 ;skip if not in portb ;is last bit a mark? ori 10h jz tro18 ;skip if mark (don't wait for stop) lhld fulldel ;delay to stop bit tro16: dcr l jnz tro16 dcr h jnz tro16 tro18: lhld wptr ; check buffer xchg lhld rptr dcx d ; decrement queue pointer mov a,d ora e jnz tro20 ; skip if no queue wrap around lxi d,maxque-1 ; wrap around tro20: mov a,l ; sub hl,de sub e mov l,a mov a,h sbb d mov h,a ora l ; check for zero jz tro22 ; skip if buffer full xchg shld wptr ; update queue lxi d,rqueue dad d mov m,c ; put char in queue tro22: ei ret ;ret ; routine for quarter bit timing ; for transmit and simultaneous receive ; total execution time is 223T + L*14T + H*34T qbit: call txrx ;17T + 162T lda txrxdel ;13T qbit2: dcr a ; 4T jnz qbit2 ;10T lda txrxdel+1 ;13T qbit4: dcr a ; 4T nop ; 4T nop ; 4T nop ; 4T nop ; 4T nop ; 4T jnz qbit4 ;10T mov a,d ; 4T Check if still sending or receiving ora e ; 4T jnz qbit ;10T ret ;simultaneous transmit/receive ;do next quarter bit ; regs: b = portb with tx bit zeroed ; c = character being received ; d = number of qtr bits remaining to send ; e = number of qtr bits remaining to receive (0 if not receiving) ; hl = character being transmitted ;this subroutine always executes in 162T (or 163T) txrx: mov a,d ; 4T qtr bits remaining to send ora a ; 4T jz txrx12 ;10T skip if no bits remaining (may be receiving) ani 03h ; 7T a complete bit? jnz txrx10 ;10T skip if not dad h ;11T shift tx bit to bit 5 of h mov a,h ; 4T ani 20h ; 7T extract tx bit ora b ; 4T combine with portb out portb ;11T send it txrx2: dcr d ; 4T one less qtr bit to send ;76T total ;now receive part txrx4: mov a,e ; 4T qtr bits remaining to receive ora a ; 4T jz txrx16 ;10T skip if not receiving ani 3h ; 7T a complete bit? jnz txrx14 ;10T skip if not in portb ;11T get input ani 10h ; 7T extract rx bit sui 1 ; 7T bit to carry mov a,c ; 4T bit to c rar ; 4T mov c,a ; 4T txrx6: dcr e ; 4T one less qtr bit to receive txrx8: ret ;10T ;86T total ;come here if transmitting, but not a complete bit ;delay to match up execution times txrx10: ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ori 00h ; 7T jmp txrx2 ;10T ;come here if not sending (but still receiving) ;delay to match up execution times txrx12: ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T jmp txrx4 ;10T ;come here if receiving (but not a complete bit) ;delay to match up execution time txrx14: ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ori 00h ; 7T jmp txrx6 ;10T ;come here if not receiving txrx16: in portb ;11T check if start bit ani 10h ; 7T jz txrx18 ;10T skip if mark mvi e,rqbit ; 7T get quarter bit count for receive xra a ; 4T sta trtemp ;13T store flag to say we are receiving ori a ; 7T delay (should be 6T) ret ;10T txrx18: ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T ora a ; 4T jmp txrx8 ;10T ; RS232 input interrupt routine ; stores received character in queue ; ;semi delay starts here intb: ;20T (approx.) for interrupt push psw ;11T push b ;11T push d ;11T push h ;11T in portb ;11T ani 10h ; 7T test input for start bit jz intb16 ;10T skip if no start bit. out 09h ;11T lhld semidel ;16T half bit delay intb2: dcr l ; 4T jnz intb2 ;10T inner loop 14T*L dcr h ; 4T jnz intb2 ;10T outer loop (14*H + 256*14*(H-1))T mvi e,8 ; 6T number of data bits ;semi delay ends here (125T + delay loop) ;full delay starts here intb4: lhld fulldel ;16T full bit delay intb6: dcr l jnz intb6 dcr h jnz intb6 ; 14*L + 14*H + 3584*(H-1) in portb ;11T test input ani 10h ; 7T sui 1 ; 7T input bit to carry mov a,c ; 4T rar ; 4T mov c,a ; 4T and then to C dcr e ; 4T bit count jnz intb4 ;10T loop till all data bits collected ;full delay ends here (67T + delay loop) in portb ani 10h jz intb12 ; skip if mark lhld fulldel ; wait for stop bit intb10: dcr l jnz intb10 dcr h jnz intb10 intb12: lhld wptr ; check buffer xchg lhld rptr dcx d ; decrement queue pointer mov a,d ora e jnz intb14 ; skip if no queue wrap around lxi d,maxque-1 ; wrap around intb14: mov a,l ; sub hl,de sub e mov l,a mov a,h sbb d mov h,a ora l ; check for zero jz intb16 ; skip if buffer full xchg shld wptr ; update queue lxi d,rqueue dad d mov m,c ; put char in queue intb16: pop h pop d pop b pop psw ei db 0EDh,4Dh ;reti ; ; get char from serial port buffer. ; exit: A=char or Z if no char rsin: push d push h lhld rptr xchg lhld wptr mov a,l ;sub hl,de sub e mov l,a mov a,h sbb d mov h,a ora l ;check for zero jnz rsi4 ;get char rsi2: pop h pop d ret rsi4: push psw dcx d ; decrement queue pointer mov a,d ora e jnz rsi6 ; skip if no queue wrap around lxi d,maxque-1 ; wrap around rsi6: pop psw xchg shld rptr lxi d,rqueue dad d mov e,m ;get char from queue ori 0ffh ;set NZ mov a,e jmp rsi2 ; printer routines inta: sta ptemp mvi a,0 sta pflag lda ptemp ei db 0EDh,4Dh ;reti parout: push h lxi h,pflag par2: db 0CBh,46h ;bit 0,(hl) jnz par2 mvi m,0ffh out porta pop h ret ; data storage oldint: db 0 ; storage for old i reg trtemp: db 0 ptemp: db 0 ;temp storage used by inta interrupt pflag: db 0 ;0ffh if waiting for printer. 00h if ready ;receive queue pointers maxque equ 2048 ; receiver queue size rptr: dw maxque-1 wptr: dw maxque-1 ;transmit ndata equ 8 ; 8 data bits nstrt equ 1 ; 1 start bit nstop equ 1 ; 1 stop bit ntotal equ nstrt+ndata+nstop rqbit equ 4*(nstrt+ndata) ;number of quarter bits to receive tqbit equ 4*(nstrt+ndata+nstop) ;number of quarter bits to transmit tqfudge equ 13-nstrt-ndata ;H=0 or L=0 behave as 256 ;receive delays. fulldel: dw 0 ; 3584(H-1) + 14H + 14L + 67 cycles semidel: dw 0 ; 3584(H-1) + 14H + 14L + 125 cycles ;1/4 bit transmit and simultaneous tx/rx delay 34H + 14L + 223 cycles ;or full bit delay 3584(H-1) + 14H + 14L + 74 cycles txrxdel: dw 0 ; txcall: dw trout ; address of subroutine to transmit char ; receiver queue rqueue: ds maxque ovlend equ $ ; End of overlay IF lasm END ENDIF