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- TITLE 'MEX RACAL-VADIC VA3451 AUTO DIAL - V1.0'
- ;
- ; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM)
- ;
- ; MXO-RT10.ASM Original release 6/13/84
- ;
- ; Racal Vadic VA3451 overlay for MEX: revision 1.0
- ; Written 13 June 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
- ;
- ; 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
- ;
- ; Note: For the disconnect to work properly, you MUST have DISCV
- ; implemented in your normal machine overlay. This file
- ; is overlayed in addition to your overlay.
- ; Also, your overlay MUST have the entry point NEWBDV that
- ; allows this program to set the baud rate by passing a
- ; single byte parameter in the A register.
- ; See Ron Fowler's overlay for the GodBout S-100 board for
- ; examples of these routines.
- ;
- FALSE EQU 0
- TRUE EQU NOT FALSE
- ;
- ;
- ; 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
- ;
- MSPEED EQU 107H ; Variable in hardware overlay
- NEWBDV EQU 16EH ; Entry in overlay to set baud rate
- ;
- ;
- 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
- XRA A
- STA BDFLAG ; Zero BDFLAG
- LDA MSPEED ; Get baud rate set by MEX
- CPI 5 ; 1200 baud ???
- JZ CLEAR ; Nothing to do if 1200 baud
- STA BDSAVE ; Save baud rate locally
- MVI A,TRUE ; Else, set flag
- STA BDFLAG
- MVI A,1 ; If not 1200 baud then set 300
- CALL NEWBDV ; baud for dialing
- 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 STWAIT ; After "HELLO..."
- LXI H,DCMD ; Send "dial" command to modem
- CALL RVSEND
- CALL SENDCR ; Terminate dial command
- LXI H,DIALBF ; Point to number
- CALL RVSEND ; Send it to modem
- CALL SENDCR ; Send <cr> to terminate phone number
- LXI H,CRMSG ; Second <cr> to initiate dialing
- CALL RVSEND
- ;
- ; 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 RETRN ; No, 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,2 ; Timed out waiting for answer
- JMP IDLE ; Disconnect and return error code
- DIAL05:
- CPI 2 ; Failed call ?
- JZ ERRET ; Error return
- CPI 1 ; Dialing message ?
- JNZ DIAL10
- MVI C,ILP
- CALL MEX
- DB 'Dialing...',0
- JMP DLOOP
- DIAL10:
- CPI 3 ; On line ?
- JNZ ERRET
- XRA A ; Return on line code to MEX
- RETRN:
- PUSH PSW ; Save return code
- RET03:
- LDA BDFLAG ; See if we have to reset baud rate
- ORA A
- JZ RET05 ; Return if no
- LDA BDSAVE ; Get saved rate code
- CALL NEWBDV ; Set old baud again
- RET05:
- POP PSW ; Get return code
- RET
-
- 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
- CALL DISCV ; Make sure modem disconnects
- LXI H,IDLCMD ; Send idle command
- CALL RVSEND
- JMP RET03
-
- 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>
-
- STWAIT:
- MVI C,INMDM ; Get one character from modem
- CALL MEX
- JC STWAIT ; If time out, wait
- CPI '*' ; Is it the "*" prompt ?
- JNZ STWAIT
- RET
-
-
- ; Table of valid responses from modem
- RSPTBL:
- DB 'HE',0 ; "hello..."
- DB 'DI',0 ; "dialing..."
- DB 'FA',0 ; "failed call"
- DB 'ON',0 ; "on line"
- 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
- MOV A,B ; Initialize space flag
- STA SPFLAG
- 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 ' ' ; End of "DIALING: "
- JZ CRSPC ; Handle space character
- 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
- ;
- ; Handle space character, two in a row means the end of the
- ; modem response "DIALING: ".
- ;
- CRSPC:
- LDA SPFLAG ; Get space flag
- ORA A
- JNZ EOL ; This must be the second one in a row
- CMA ; Otherwise, set the flag, it is the
- STA SPFLAG ; first one, flag it
- JMP CRLOOP ; Loop for more characters
- ;
- ; 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:
- PUSH H ; Save memory pointer
- RV05:
- MVI C,SNDRDY ; Get modem send status
- CALL MEX
- JNZ RV05 ; Wait for modem ready
- MVI B,1 ; Wait 1ms for modem software uart
- MVI C,TIMER
- CALL MEX
- POP H ; Restore pointer
- 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
- JMP RVSEND
-
- ;
- ; 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
- SPFLAG: DS 1 ; Space flag for catch response routine
- BDFLAG: DS 1 ; True for 450 or 600 baud
- BDSAVE: DS 1 ; Save for MSPEED code for 450 or 600
- RESPBF: DS 20 ; Response from modem
- DIALBF: DS 30 ; Phone number buffer
- DIALPT: DS 2 ;DIAL POSITION POINTER
- ;
- END