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Assembly Source File | 1994-07-13 | 14.3 KB | 478 lines

TITLE 'MEX RACAL-VADIC VA212 OVERLAY V1.0' ; ; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM) ; ; MXO-RV10.ASM Original release 5/20/84 ; ; Racal Vadic VA212 overlay for MEX: revision 1.0 ; Written 20 May 1984 by Dave Mabry ; Adapted using information and excerpts from Ron Fowler's ; overlay for the PMMI modem. ; ; Please leave any bug reports or requests on TCBBS in Dearborn, ; Michigan (313-846-6127) or Royal Oak RCPM (313-759-6569) ; or call me at 313-956-5703 (voice). mabry ; ; Updates: ; MXO-RV11.ASM: ; 5/21/84...Fixed bug in Busy handler that left modem in ; "terminal" mode. This caused no problems but it ; wasn't "clean". ; MXO-RV12.ASM ; 5/22/84...Added code to ensure the modem is left in ; "idle" state after busy signal returned. ; Major rewrite with debugging done using a data line ; monitor. This version should work without problems ; on all systems. ; MXO-RV13.ASM ; 8/25/84...Major change. This overlay now supports both ; the VA3451 (w auto-dial ROM) and the VA212. Set OLDVA ; to true to include VA3451 code. (Look for "IF OLDVA" to ; find additions.) ; Bob Horn ; ; Note that unlike the Hayes modem, the Racal Vadic does not ; have an ascii command that will cause a disconnect. Therefore ; for that feature of MEX to work properly, your normal overlay ; for your machine must be able to toggle DTR in the DISCV routine. ; ; This overlay will work with any modem overlay that terminates ; prior to 0B00H ; FALSE EQU 0 TRUE EQU NOT FALSE OLDVA EQU TRUE ;TRUE if VA3451 instead of VA212 ; ; ; SYSTEM CONSTANTS ; DIALV EQU 0162H ;LOCATION OF DIAL VECTOR IN OVERLAY DISCV EQU 0165H ;LOCATION OF DISCONNECT VECTOR IN OVERLAY DIALOC EQU 0B00H ;DIALING CODE GOES HERE ; ; ; MEX service processor stuff ... MEX supports an overlay service ; processor, located at 0D00H (and maintained at this address from ; version to version). If your overlay needs to call BDOS for any ; reason, it should call MEX instead; function calls below about ; 240 are simply passed on to the BDOS (console and list I/O calls ; are specially handled to allow modem port queueing, which is why ; you should call MEX instead of BDOS). MEX uses function calls ; above about 244 for special overlay services (described below). ; ; Some sophisticated overlays may need to do file I/O; if so, use ; the PARSFN MEX call with a pointer to the FCB in DE to parse out ; the name. This FCB should support a spare byte immediately pre- ; ceeding the actual FCB (to contain user # information). If you've ; used MEX-10 for input instead of BDOS-10 (or you're parsing part ; of a SET command line that's already been input), then MEX will ; take care of DU specs, and set up the FCB accordingly. There- ; after all file I/O calls done through the MEX service processor ; will handle drive and user with no further effort necessary on ; the part of the programmer. ; MEX EQU 0D00H ;address of the service processor INMDM EQU 255 ;get char from port to A, CY=no more in 100 ms TIMER EQU 254 ;delay 100ms * reg B TMDINP EQU 253 ;B=# secs to wait for char, cy=no char CHEKCC EQU 252 ;check for ^C from KBD, Z=present SNDRDY EQU 251 ;test for modem-send ready RCVRDY EQU 250 ;test for modem-receive ready SNDCHR EQU 249 ;send a character to the modem (after sndrdy) RCVCHR EQU 248 ;recv a char from modem (after rcvrdy) LOOKUP EQU 247 ;table search: see CMDTBL comments for info PARSFN EQU 246 ;parse filename from input stream BDPARS EQU 245 ;parse baud-rate from input stream SBLANK EQU 244 ;scan input stream to next non-blank EVALA EQU 243 ;evaluate numeric from input stream LKAHED EQU 242 ;get nxt char w/o removing from input GNC EQU 241 ;get char from input, cy=1 if none ILP EQU 240 ;inline print DECOUT EQU 239 ;decimal output PRBAUD EQU 238 ;print baud rate ; ; CONOUT EQU 2 ;simulated BDOS function 2: console char out PRINT EQU 9 ;simulated BDOS function 9: print string INBUF EQU 10 ;input buffer, same structure as BDOS 10 ; ; CR EQU 13 LF EQU 10 ; ; ORG DIALV ;OVERLAY THE DIALING VECTOR JMP DIAL ; ; ; This is the DIAL routine called by MEX to dial a digit. The digit ; to be dialed is passed in the A register. Note that two special ; codes must be intercepted as non-digits: 254 (start dial sequence) ; and 255 (end-dial sequence). Mex will always call DIAL with 254 ; in the accumulator prior to dialing a number. Mex will also call ; dial with 255 in A as an indication that dialing is complete. Thus, ; the overlay may use these values to "block" the number, holding it ; in a buffer until it is completely assembled (in fact, that's the ; scheme employed here for the Racal Vadic). ; ; After the 254-start-dial sequence, MEX will call the overlay with ; digits, one-at-a-time. MEX will make no assumptions about the dig- ; its, and will send each to the DIAL routine un-inspected (some modems, ; like the Smartmodem, allow special non-numeric characters in the ; phone number, and MEX may make no assumptions about these). ; ; After receiving the end-dial sequence (255) the overlay must take ; whatever end-of-dial actions are necessary *including* waiting for ; carrier at the distant end. The overlay should monitor the keyboard ; during this wait (using the MEX keystat service call), and return ; an exit code to MEX in the A register, as follows: ; ; 0 - Carrier detected, connection established ; 1 - Far end busy (only for modems that can detect this condition) ; 2 - No answer (or timed out waiting for modem response) ; 3 - Keyboard abort (^C only: all others should be ignored) ; 4 - Error reported by modem ; ; <No other codes should be returned after an end-dial sequence> ; ; The overlay should not loop forever in the carrier-wait routine, but ; instead use either the overlay timer vector, or the INMDMV (timed 100 ; ms character wait) service call routine. ; ; The DIAL routine is free to use any of the registers, but must return ; the above code after an end-dial sequence ; ORG DIALOC ; DIAL: LHLD DIALPT ;FETCH POINTER CPI 254 ;START DIAL? JZ STDIAL ;JUMP IF SO CPI 255 ;END DIAL? JZ ENDIAL ;JUMP IF SO ; ; Not start or end sequence, must be a digit to be sent to the modem ; MOV M,A ;PUT CHAR IN BUFFER INX H ;ADVANCE POINTER SHLD DIALPT ;STUFF PNTR RET ;ALL DONE ; ; Here on a start-dial sequence ; STDIAL: LXI H,DIALBF ;SET UP BUFFER POINTER SHLD DIALPT RET ; ; Here on an end-dial sequence ; ENDIAL: MVI M,0 ; Terminate phone number string CLEAR: MVI C,INMDM ; Clean out the data buffer in usart CALL MEX JNC CLEAR ; Get all available LXI H,WAKEUP ; Get modem's attention CALL RVSEND CALL LFWAIT ; First thing after ^E,<cr> RNZ ; Return if time out CALL LFWAIT ; After "HELLO..." RNZ ; Return if time out LXI H,DCMD ; Send "dial" command to modem CALL RVSEND CALL SENDCR ; Terminate dial command CALL LFWAIT ; Wait for "NUMBER?" prompt RNZ ; Return if not normal return from LFWAIT LXI H,DIALBF ; Point to number CALL RVSEND ; Send it to modem CALL SENDCR ; Send <cr> to terminate phone number IF OLDVA CALL DELAY ; .5 second wait if VA3400 ENDIF CALL SENDCR ; Send second <cr> to initiate dialing RNZ ; ; Here starts the main loop waiting for messages from the modem ; and interpreting them. Some are just passed to the console ; and others trigger a specific action. ; DLOOP: LXI H,RESPBF ; Point to response buffer MVI C,255 ; Long wait here CALL CATCHR ; Catch response from modem ORA A ; Zero return code ? JNZ IDLE ; No, disconnect and return error code MOV A,B ; Get character count from CATCHR ORA A ; Hope it isn't zero JZ DLOOP ; If it is, then ignore this response LXI H,RESPBF ; Point to string from modem LXI D,RSPTBL ; Point to valid response table CALL COMPR ; Find out which response we got MOV A,B ; Get return value CPI 255 ; No response match JNZ DIAL05 ERRET: MVI A,4 ; Error return to MEX JMP IDLE ; Disconnect and return error code DIAL05: CPI 3 ; Failed call ? JNZ DIAL06 ; Say so and error return IF OLDVA MVI A,2 JMP IDLE ENDIF IF NOT OLDVA JMP ERRET ENDIF DIAL06: CPI 1 ; Dialing message ? JNZ DIAL10 MVI C,ILP CALL MEX DB 'Dial, ',0 JMP DLOOP DIAL10: CPI 2 ; Ringing ? JNZ DIAL15 MVI C,ILP CALL MEX DB 'ring, ',0 JMP DLOOP DIAL15: CPI 4 ; Answer tone ? JNZ DIAL20 MVI C,ILP CALL MEX DB 'answer, ',0 JMP DLOOP DIAL20: CPI 5 ; On line ? JNZ DIAL25 XRA A ; Return on line code to MEX RET DIAL25: CPI 7 ; Busy ? JNZ DIAL35 CALL LFWAIT ; Busy message has 2 <lf>'s RNZ ; If timeout or user abort DIAL30: MVI A,1 ; Return busy code to MEX JMP IDLE ; Disconnect and return error code DIAL35: CPI 8 ; Voice ? JNZ ERRET ; If there was a match not handled above ; ; Handle "VOICE" here ; CALL SENDCR ; <cr> ends the "voice" mode JMP DIAL30 ; Abort and return busy code to MEX IDLE: ; ; Forces modem into idle state by sending "idle" command and ; then toggling DTR using the user's DISCV entry. ; Preserves any return code that may be in register A. ; PUSH PSW ; Preserve any return code IF OLDVA CALL LFWAIT ENDIF IF NOT OLDVA CALL SENDCR ; Abort any dialing taking place ENDIF LXI H,IDLCMD ; Send idle message to modem CALL RVSEND CALL DISCV ; Make sure modem disconnects POP PSW ; Retrieve return code RET SENDCR: ; ; Sends a carriage return character to the modem and waits for a ; line feed character to be returned. ; LXI H,CRMSG ; Send <cr> to modem CALL RVSEND ; Note: execution falls through to LFWAIT ; ; Waits til the character from the modem is a line feed ; Returns the same codes as CATCHR. ; LFWAIT: MVI C,10 ; Up to one second for <lf> LXI H,RESPBF JMP CATCHR ; Use CATCHR to wait for <lf> ; Table of valid responses from modem RSPTBL: DB 'HE',0 ; "hello..." DB 'DI',0 ; "dialing..." DB 'RI',0 ; "ringing..." DB 'FA',0 ; "failed call" DB 'AN',0 ; "answer tone" DB 'ON',0 ; "on line" DB 'NO',0 ; "no dial tone" DB 'BU',0 ; "busy" DB 'VO',0 ; "voice" DB 0 ; Table terminator COMPR: ; Compares a string of characters in memory to a table of ; strings. Each entry of the table must be terminated by ; a zero byte, and the table must be terminated by another ; zero byte. ; Inputs: HL points to the string to look for ; DE points to the table ; Output: B contains the number of the table entry that ; matches the string, and a 255 if no entry matched. ; MVI B,0 ; Init index CMPR05: MVI C,2 ; Number of characters to try to match CMPR10: LDAX D ; Fetch char from table CMP M ; Same as char in string ? JNZ CMPR15 ; Jump if not this entry in table INX H ; Else, point to next char in string INX D ; and next char in table entry DCR C ; Decrement counter of characters JNZ CMPR10 ; Go check next char RET ; B contains the index of match CMPR15: INR B ; Increment index CMPR20: INX D ; Next char in table LDAX D ; Get next char from table ORA A ; Is it last char in that entry ? JNZ CMPR20 ; No, keep looking INX D ; Yes, then point to first char of next one LDAX D ; Now check for end of table ORA A ; Zero delimits table JNZ CMPR05 ; Go check this table entry MVI B,255 ; No match return code RET CATCHR: ; ; Catch response from modem. ; Input: HL pointing to buffer for characters from modem ; C delay allowed before timeout (multiples of 100ms) ; Output: Buffer contains the string received from modem with ; any control characters filtered out. ; C count of characters received before <cr> ; A error code: 0 ==> normal return ; 2 ==> time out occurred ; 3 ==> user typed ^C ; MVI B,0 ; Character counter CRLOOP: MOV D,C ; Initialize count down timer CRL05: PUSH B ; Save character counter PUSH D ; Save time out count down PUSH H ; Save buffer pointer MVI C,CHEKCC ; See if user typed ^C CALL MEX JZ UABORT ; If yes, jump to user abort code MVI C,INMDM ; Else, continue CALL MEX ; Get char in 1ms if available POP H ; Restore working registers POP D POP B JC NOCHAR ; If no char in 1ms, handle it ANI 7FH ; Mask any parity bit CPI LF ; End of line from modem ? JZ EOL ; If <lf> then end of line CPI ' ' ; Filter unwanted characters JC CRLOOP ; Ignore control characters CPI 'z'+1 ; Nothing above lower case alpha's JNC CRLOOP MOV M,A ; Here we have a valid character INX H ; so save it and bump pointer INR B ; Increment character counter also JMP CRLOOP ; Go get the next one ; ; Handle no character from modem in 1ms ; NOCHAR: DCR D ; Decrement time out counter JNZ CRL05 ; If not to zero, wait some more MOV C,B ; Else, return with what we have now MVI A,2 ; Time-out error code RET ; ; End of line from modem ; EOL: MOV C,B ; Character count XRA A ; Return zero RET ; ; User abort from ^C ; UABORT: CALL IDLE ; Force disconnect POP H ; Since these are still on the stack POP D POP B MOV C,B ; Count of characters up to now MVI A,3 ; User abort code RET ; ; Sends a string of characters pointed to by HL terminated by zero ; RVSEND: MVI C,SNDRDY ; Get modem send status CALL MEX JNZ RVSEND ; Wait for modem ready MOV A,M ; Get character INX H ; Point to next character ORA A ; Is this the terminator ? RZ ; If yes, done MOV B,A ; Pass character in B MVI C,SNDCHR ; Let MEX send to modem CALL MEX IF OLDVA CALL DELAY ; .5 second delay here ENDIF JMP RVSEND ; IF OLDVA ; ; Provide a 0.5 second delay between command characters to the modem ; DELAY: PUSH H ;Save all registers PUSH D PUSH B PUSH PSW MVI B,5 ;Number of 100 mS intervals MVI C,TIMER CALL MEX POP PSW ;Restore registers POP B POP D POP H RET ; ENDIF ; ; DATA AREA ; WAKEUP: DB 'E'-40H,CR,0 ; String to wake up modem IDLCMD: DB 'I',CR,0 ; Idle command DCMD: DB 'D',0 ; Dial command to modem CRMSG: DB CR,0 ; Note, this is end of DCMD RESPBF: DS 20 ; Response from modem DIALBF: DS 30 ; Phone number buffer DIALPT: DS 2 ;DIAL POSITION POINTER ; END