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- TITLE 'MEX VENTEL MD212 PLUS MODEM OVERLAY V1.0'
- ;
- ; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM)
- ;
- ; used smartmodem overlay for MEX: revision 1.2
- ; Written 04/16/84 by Ronald G. Fowler (V1.2) as an outline.
- ;
- ; Written by:
- ; Bruce Childers & Jon Albers
- ; Data - 202-633-0804, 0805, 0806
- ; 703-281-7907
- ;
- ; This overlay will allow you to use a Ven-Tel Plus modem with Mex.
- ; It will allow auto-dial. Note -- You can only disconnect using
- ; DTR, so set the DISC equatte to false.
- ;
- ; This overlay will work with any modem overlay that terminates
- ; prior to 0B00H
- ;
- FALSE EQU 0
- TRUE EQU NOT FALSE
- ;
- ;
- DISC EQU FALSE ;<<== CHANGE TO FALSE IF YOU DISC. WITH DTR
- PENRIL EQU FALSE ;Set true if you have a Penril
- ;
- ; 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 EQU 0D00H ;"CALL MEX"
- ;
- ; FOLLOWING ARE FUNCTION CODES FOR THE MEX SERVICE CALL PROCESSOR
- ;
- INMDM EQU 255 ;RETURN CHAR FROM MDM IN A, CY=NO CHR IN 100MS
- TIMER EQU 254
- 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)
- ;
- CR EQU 13
- LF EQU 10
- ;
- ;
- ;
- ORG DIALV ;OVERLAY THE DIALING VECTOR
- JMP DIAL
- ;
- IF DISC ;IF PROVIDING DISCONNECT CODE
- ORG DISCV ;OVERLAY THE VECTOR
- JMP DISCON
- ENDIF
- ;
- ; 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.
- ; 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: 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
- ;
- CALL SEND ;SEND CHARACTER TO MODEM
- RET ;ALL DONE
- ;
- ; Here on a start-dial sequence
- ;
- STDIAL: CALL SETUP ;WAKE UP THE VENTEL
- RET
- ;
- ; Here on an end-dial sequence
- ;
- ENDIAL: MVI A,CR ;PUT A CR AT THE END
- CALL SEND ;SEND CR TO MODEM
-
- WAITVP: MVI C,INMDM
- CALL MEX ;CATCH ANY OUTPUT FROM THE MODEM
- JNC WAITVP ;LOOP UNTIL NO MORE CHARACTERS
- ;
- ; THE FOLLOWING LOOP WAITS FOR A RESULT FROM THE MODEM (UP TO
- ; 60 SECONDS: YOU MAY CHANGE THIS VALUE IN THE FOLLOWING LINE).
- ;
- RESULT: MVI C,60 ;<<== MAXIMUM TIME TO WAIT FOR RESULT
- VPWLP: PUSH B
- MVI B,1 ;CHECK FOR A CHAR, UP TO 1 SEC WAIT
- MVI C,TMDINP ;DO TIMED INPUT
- CALL MEX
- POP B
- JNC VPTEST ;JUMP IF MODEM HAD A CHAR
- PUSH B ;NO, TEST FOR CONTROL-C FROM CONSOLE
- MVI C,CHEKCC
- CALL MEX
- POP B
- JNZ VPNEXT ;IF NOT, JUMP
- MVI B,CR ;YES, SHUT DOWN THE MODEM
- MVI C,SNDCHR
- CALL MEX
- MVI A,3 ;RETURN ABORT CODE
- RET
- VPNEXT: DCR C ;NO
- JNZ VPWLP ;CONTINUE
- ;
- ; ONE MINUTE WITH NO MODEM RESPONSE (OR NO CONNECTION)
- ;
- VPTIMO: MVI A,2 ;RETURN TIMEOUT CODE
- RET
- ;
- ; MODEM GAVE US A RESULT, CHECK IT
- ;
- VPTEST: ANI 7FH ;IGNORE ANY PARITY
- CALL VPANAL ;TEST THE RESULT
- MOV A,B ;A=RESULT (CY SIGNIFICANT HERE TOO)
- PUSH PSW ;SAVE IT
- VPTLP: MVI C,INMDM ;FLUSH ANY REMAINING COMMAND LINE
- CALL MEX
- JC VPCHEK ;JUMP IF NO INPUT
- CPI LF ;GOT SOME ... WAITING FOR EOL
- JNZ VPTLP ;EAT ANY IN-BETWEEN
- VPCHEK: POP PSW ;A HAS MEX RETURN-CODE, CY=1 IF UNKNOWN
- JC RESULT ;IF RESULT UNKNOWN, IGNORE IT
- RET
- ;
- VPANAL: MVI B,0 ;PREP CONNECT CODE
- CPI 'O' ;"CONNECT"?
- RZ
- INR B ;PREP BUSY CODE B=1
- CPI 'B'
- RZ
- INR B ;PREP NO CONNECT MSG B=2
- CPI 'N' ;N=NO CONNECT
- RZ
- MVI B,4 ;PREP MODEM ERROR
- CPI 'E' ;E=ERROR
- RZ
- STC ;UNKNOWN...
- RET
- ;
- ; SET UP ROUTINE TO WAKE VEN-TEL UP
- ;
- SETUP: MVI C,SNDRDY ;CHECK TO SEE IF MODEM IS ALIVE
- CALL MEX
- JNZ SETUP
- MVI A,CR ;send first cr of 3
- CALL SEND
- CALL DELAY1 ;Wait to avoid sending CR's too fast for modem
- SETUP2: MVI C,SNDRDY
- CALL MEX
- JNZ SETUP2
- MVI A,CR ;send second cr
- CALL SEND
- CALL DELAY1
- SETUP3: MVI C,SNDRDY
- CALL MEX
- JNZ SETUP3
- MVI A,CR ;send third cr
- CALL SEND
- MVI B,30 ;Wait to get past banner
- MVI C,TIMER
- CALL MEX
- CALL DELAY1
- KOUT: MVI C,SNDRDY
- CALL MEX
- JNZ KOUT
- MVI B,'K' ;GET READY TO DIAL
- MVI C,SNDCHR
- CALL MEX
- CALL DELAY1
- RET
- ;
- DELAY1: MVI B,5 ;Delay routine
- MVI C,TIMER
- CALL MEX
- RET
-
- ; SEND A CHARACTER TO THE MODEM
- ;
- SEND: MOV B,A ;WHEN CALLING HERE, THE CHAR IS IN A
- MVI C,SNDCHR
- CALL MEX
- RET
- ; End of Overlay
- END