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mxo-ct14.asm
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Assembly Source File
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1994-07-13
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12KB
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367 lines
; TITLE 'MEX CTS COMPANION MODEM OVERLAY V1.4'
;
; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM)
;
; CTS Companion modem 212AH overlay for MEX: revision 1.4
;
; Misc. little fixes 14feb85 to 18feb85 not distributed until final date (v1.4)
; Modified delay to make DSC & abort work consistently 10feb85 I S Wolfe (v1.3)
; Modified for auto baud rate change on CTS-212AH 10feb85 by I S Wolfe (v1.2)
; a bug in the TYPE routine was fixed & some other problems solved.
; Originally written 07/24/84 by Ronald G. Fowler (V1.0)
;
; ATTENTION: READ THIS PARAGRAPH BEFORE USING:
; This module adapts MEX for the CTS 212AH modem, but the MEX standard of
; keeping modem & computer overlays independent prevents complete adaptation.
; The module primarily provides dialing capability with automatic
; resetting of the modem with ^T so that baud rate changes can be initiated
; with ^Q^M before the dialing sequence. NOTE THAT THE USER MUST RESET THE
; MODEM MANUALLY AFTER A COMPLETED CONVERSATION BY TYPING ^T WHILE STILL IN
; TERMINAL MODE. Resets should occur automatically after a Busy, No answer,
; No tone, or Abort response from the modem. Letters from the modem are
; displayed so the user can track a call's progress: D for dialing, R for ring,
; B for busy, etc. -- I S Wolfe 10feb85
;
;THIS DISCUSSION IS BY RON FOWLER. I S Wolfe believes it is reasonable but
;only conjectural, and that until you experience trouble, don't worry:
; You may want to disable the ^T disconnect character by issuing
; the "@@" command in terminal mode (although this will defeat the
; DISC option below, and require disconnect support be handled through
; DTR control in your hardware overlay). This will sometimes be
; desirable to avoid disconnect problems when transmitting files
; in protocol mode over packet-switched networks (eg, Arpa and Compu-
; serve), where a block ending in control T could cause a disconnect
; if it takes more than one second for the ACK or NAK sequence to
; return from the remote end. This will not usually be necessary
; for RCPM work, since character turnaround is normally much less
; than one second.
;
; The only conditional you might want to change in this
; module is the DISC equate below -- if left on, MEX will
; use the Companion's disconnect code. If you prefer to
; provide your own in your overlay's DISCV vector (e.g.,
; by dropping DTR), then set DISC to FALSE and re-assemble.
; (If you don't understand this, then play it safe, and
; leave the equate set as it is).
;
; This overlay will work with any modem overlay that terminates
; prior to 0B00H
;
FALSE EQU 0
TRUE EQU NOT FALSE
;
NUMRES EQU FALSE ; TRUE = INTERPRET NUMERIC RESULT CODES
; FALSE = IGNORE NUMERIC RESULT CODES
;
DISC EQU TRUE ;<<== CHANGE TO FALSE IF YOU DISC. WITH DTR
;
; SYSTEM CONSTANTS
;
TPULSE EQU 0105H ;TONE/PULSE FLAG IN MODEM OVERLAY
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"
BDOS EQU 0005H ;for call bdos in TYPE -- in case it becomes necessary
;
; 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
CTRLT EQU 20 ;added by isw
CTRLQ EQU 17 ;added by isw
CONOUT EQU 2 ;added by isw
;
ORG DIALV ;OVERLAY THE DIALING VECTOR
JMP DIAL
;
IF DISC ;IF PROVIDING DISCONNECT CODE here (we do)
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 (in fact, that's the
; scheme Ron Fowler employed here for the CTS modem).
;
; After the 254-start-dial sequence, MEX will call the overlay with
; digits, one-at-a-time. MEX will make no assumptions about the digits,
; and will send each to the DIAL routine un-inspected (some modems,
; like the CTS modem, 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 ;DONE with this "digit"
;
; Here on a start-dial sequence
;
STDIAL:
;
LXI H,CTSPED ;SEND ^Q^M ;inserted here by isw to set modem speed
CALL CTSEND ;after modem was reset entirely by extra ^t.
;
LXI H,DIALBF ;SET UP BUFFER POINTER
SHLD DIALPT
RET
;
; Here on an end-dial sequence
;
ENDIAL:
;
MVI M,CR ;STUFF END-OF-LINE INTO BUFFER
INX H ;FOLLOWED BY null TERMINATOR
MVI M,0
LDA TPULSE ;GET OVERLAY'S TOUCH-TONE FLAG
STA CTDIAL ;put it into the dialing command
;
ENDL0: ;added by isw to pick up & discard "modem ready" from the ^q^m
;
MVI C,INMDM ;CLEAR ANY WAITING MODEM CHARACTERS
CALL MEX
JNC ENDL0 ;LOOP UNTIL NO MORE
;
LXI H,CTDIAL ;POINT TO DIALING STRING
CALL CTSEND ;SEND IT
;
WAITSM:
;
MVI C,INMDM
CALL MEX ;CATCH ANY OUTPUT FROM THE MODEM
JNC WAITSM ;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
;
SMWLP:
;
MVI B,1 ;CHECK FOR A CHAR, UP TO 1 SEC WAIT
MVI C,TMDINP ;DO TIMED INPUT
CALL MEX
JNC SMTEST ;JUMP IF MODEM HAD A CHAR
MVI C,CHEKCC
CALL MEX
JNZ SMNEXT ;IF NOT, JUMP
CALL DISCON ;added by isw to replace 3 deleted lines that didn't do enough
MVI A,3 ;RETURN ABORT CODE
RET
;
SMNEXT:
;
DCR C ;NO so reduce the 60 second count
JNZ SMWLP ;CONTINUE
;
; ONE MINUTE WITH NO MODEM RESPONSE (OR NO CONNECTION)
;
SMTIMO:
;
CALL DISCON ;added by isw
MVI A,2 ;RETURN TIMEOUT CODE
RET
;
; MODEM GAVE US A RESULT, CHECK IT
;
SMTEST:
;
ANI 7FH ;IGNORE ANY PARITY
CALL SMANAL ;TEST THE RESULT
MOV A,B ;A=RESULT (CY SIGNIFICANT HERE TOO)
PUSH PSW ;SAVE IT
;
SMTLP:
;
MVI C,INMDM ;FLUSH ANY REMAINING COMMAND LINE
CALL MEX
JC SMCHEK ;JUMP IF NO INPUT
CPI LF ;GOT SOME ... WAITING FOR EOL
JNZ SMTLP ;EAT ANY IN-BETWEEN
;
SMCHEK:
;
MVI A,' ' ;isw lets display a space for formatting purposes
CALL TYPE ;isw
POP PSW ;A HAS MEX RETURN-CODE, CY=1 IF UNKNOWN
JC SMC1 ;isw go process unknown response
ORA A ;isw check for 0
RZ ;isw return now if on line
PUSH PSW ;isw save return code
CALL DISCON ;isw reset modem since not on line
POP PSW ;isw get back return code
RET ;was VALID RETURN CODE, so EXIT
;
SMC1: ;note: isw removed Ron's code, left extra jump in for possible later use
;
JMP RESULT ;AND CONTINUE, ignoring the Dialing or Ring or any unknown code
;
; ANALYZE CODE, RETURN CY=1 IF UNKNOWN CODE. VALID
; EXIT CODES COME BACK IN B, CHAR IN A IS PRESERVED
;
SMANAL:
;
CPI ' ' ;is it okay to display? added by isw to see what's going on
CNC TYPE ;call type if char from modem is greater than space
MVI B,0 ;PREP CONNECT CODE
CPI 'O' ;"ON LINE"?
RZ
INR B ;PREP BUSY CODE B=1
CPI 'B' ;B=BUSY
RZ
INR B ;PREP NO CONNECT MSG B=2
CPI 'N' ;N=NO PHONE # OR NO ANSWER OR NO DIALTONE
RZ
CPI 'M' ;M=MODEM READY which will occur after DEAD LINE gives a D
RZ
STC ;set carry means it is an UNKNOWN code
RET
;
; FOLLOWING ROUTINE DISCONNECTS (& resets) THE MODEM USING THE CTS
; DISCONNECT CODE. ALL REGISTERS ARE AVAILABLE FOR THIS FUNCTION.
; NOTHING RETURNED TO CALLER.
;
IF DISC
;
DISCON:
;
;the ^t only works, it appears (v1.4) if there are no characters flowing after
;it in EITHER direction, so I'm cutting the time to 9 tenths & waiting for a
;pause in incoming chars (adding 1 tenth +) before sending each of 3 ^t's
;
LXI H,CTDISC ;SEND ^T
CALL CTSEND
;
DCN0:
;
MVI C,INMDM ;CLEAR ANY WAITING MODEM CHARACTERS
CALL MEX
JNC DCN0 ;LOOP UNTIL NO MORE
MVI B,9 ;WAIT .9 SECOND more for 1 second total
MVI C,TIMER
CALL MEX
LXI H,CTDISC ;SEND ^T
CALL CTSEND
;
DCN3:
;
MVI C,INMDM ;wait until incoming char's are cleared & no more coming
CALL MEX
JNC DCN3 ;LOOP UNTIL NO MORE
MVI B,9 ;WAIT 1 SECOND total including inmdm loop
MVI C,TIMER
CALL MEX ;to reset modem entirely awaiting ^q^m
; LXI H,CTDISC ;SEND ^T this third one commented out to see if okay
; CALL CTSEND
;
;DCN2:
;
; MVI C,INMDM ;wait until incoming char's are cleared & no more coming
; CALL MEX
; JNC DCN2 ;LOOP UNTIL NO MORE
; MVI B,9 ;WAIT 1 SECOND total
; MVI C,TIMER
; CALL MEX ;to reset modem entirely awaiting ^q^m
;
DCN1:
; ;added to pick up & discard "disconnect"
MVI C,INMDM ;CLEAR ANY WAITING MODEM CHARACTERS
CALL MEX
JNC DCN1 ;LOOP UNTIL NO MORE
RET
;
ENDIF
;
; SEND STRING TO MODEM
;
CTSEND:
;
MVI C,SNDRDY ;WAIT FOR MODEM READY
CALL MEX
JNZ CTSEND
MOV A,M ;FETCH NEXT CHARACTER
INX H ;step the pointer
ORA A ;END? (signified by null)
RZ ;DONE IF SO
MOV B,A ;NO, POSITION FOR SENDING
MVI C,SNDCHR ;SEND THE CHARACTER
CALL MEX
JMP CTSEND
;
; TYPE CHARACTER IN A ON the SCREEN
;
TYPE:
;
PUSH H ;SAVE THE REGISTERS
PUSH D
PUSH B
PUSH PSW
MOV E,A ;ALIGN
MVI C,CONOUT ;FUNCTION CODE
CALL MEX ;call bdos via mex
POP PSW ;CLEAN UP AND EXIT
POP B
POP D
POP H
RET
;
; DATA AREA
;
CTDISC: DB CTRLT,0 ;added by isw
CTSPED: DB CTRLQ,CR,0 ;added by isw
CTDIAL: DB 'T'
DIALBF: DS 52 ;2* 24 CHAR MAX, + CR + NULL + SLOP
DIALPT: DS 2 ;DIAL POSITION POINTER
;
END