TITLE 'MEX NEC N212BR-L1 MODEM OVERLAY V1.0' ; ; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM) ; ; Original File: MXO-SM14.ASM ; ; Smartmodem overlay for MEX: revision 1.3 ; Written 04/16/84 by Ronald G. Fowler (V1.0) ; ; 19/09/86: Altered for the NEC N212BR-L1 modem command set. This uses the ; NEC modem DIAL MODE 'K' command for KEYBOARD DIAL, sending ; two CRs with a two second wait between them to wake up the modem, ; another two second wait, the 'K', wait two more seconds, then ; the phone number. ; Also removed the NUMRES equate and the associated code as it's ; not used in this overlay. ; The NEC modem returns a whole scentence from the dialing ; sequence. For instance, if you tell it to dial: 1-234-567-8901 ; the NEC modem would return: ; ; DIALING 1-234-567-8901.............(message) ; ; Where the message could be *ON LINE*, BUSY, RINGING, or ABORTED. ; So we have to search that string for valid characters. The on line ; is easy; look for a '*'. Busy look for a 'U', so the 'B' of ; 'ABORTED' doesn't trigger it, 'R' for ringing, and 'O' for ; 'ABORTED' so the 'A' in DIALING doesn't set that one off. We'll ; never see the 'O' in the on line message as the '*' grabs it first. ; This is kind of a kludge, but it works. ; This overlay assumes you are dropping DTR to disconnect. See the ; note at the DISC code if you plan to disconnect from here. ; (David Chapman) ; ; 09/05/84: Added option to check DCD to determine if a connection has ; been made. THIS IS MACHINE SPECIFIC. Also, Switch 6 on the ; Smartmodem should be UP. (David Jewett) ; ; 07/16/84: Added equate NUMRES to enable/disable numeric result code ; interpretation. Under TurboDos, the first digit of the ; phone number was being interpreted as a result code as it ; was echoed by the Anchor modem as it dialed. Set NUMRES false ; to disable numeric results. (Bob Puckett) ; ; 06/06/84: Fixed problem for Anchor users, where, when the modem returned ; "DIAL TONE", the "N" in "TONE" was being regarded as a NO-CONNECT ; code. Now we flush the entire result line before reading another. ; Also added code for numeric version of "CONNECT 1200". --RGF ; ; Small bug repaired: (V1.1) 05/14/84 (Steve Grandi): Smartmodem was not being ; flushed after a dial string so that last digit of the phone number ; was being interpreted as a numeric result code causing the program, ; for certain numbers, to give up even as the modem merrily dialed away. ; ; This modules adapts MEX for the NEC N212BR-L1 modem. It is quite ; machine specific. I don't know of any other modem that uses ; this scheme. The main function of this module is to provide ; dialing capability; the disconnect vector is ancillary. ; You may use this module as a model to develop dialing routines ; for non-standard modems (e.g., the Racal-Vadic). The only ; pertinent entry point is the DIAL routine; you'll find entry ; specs for that below. ; ; The only conditional you might want to change in this ; module is the DISC equate below -- if left on, MEX will ; use the Smartmodem'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). (Set FALSE here - dlc) ; ; This overlay will work with any modem overlay that terminates ; prior to 0B00H ; FALSE EQU 0 TRUE EQU NOT FALSE ; ; DCD EQU FALSE ; TRUE = CHECK DCD FOR CARRIER IF DCD ; if using DCD, we must know the following: STPORT EQU 0EDH ; ... Status Port assignment to get DCD DCDBIT EQU 0100$0000b ; ... Bit HIGH to test for DCD ENDIF ; DCD ; DISC EQU FALSE ;<<== 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" ; ; 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) ILP EQU 240 ;INLINE PRINT ; 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 (in fact, that's the ; scheme employed here for the Smartmodem). ; ; 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,CR ;STUFF END-OF-LINE INTO BUFFER INX H ;FOLLOWED BY TERMINATOR MVI M,0 MVI B,CR ; Send a couple of CRs to put the MVI C,SNDCHR ; modem in the interactive mode. CALL MEX ; If it's already there thats ok too. MVI B,20 ; Two second wait MVI C,TIMER CALL MEX MVI B,CR ; There goes the second one MVI C,SNDCHR CALL MEX MVI B,20 ; And another 2 seconds MVI C,TIMER CALL MEX MVI B,'K' ; Keyboard dial in NEC modem MVI C,SNDCHR CALL MEX MVI B,20 ; Wait a couple of seconds MVI C,TIMER CALL MEX LXI H,DIALBF ;POINT TO DIALING STRING CALL SMSEND ;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). ; NOTE THAT THE SMARTMODEM HAS AN INTERNAL 30 SECOND TIMEOUT WHILE ; FOR A CARRIER ON THE OTHER END. YOU CAN CHANGE BY PLAYING WITH THE ; S7 VARIABLE (I.E. SEND THE SMARTMODEM "AT S7=20" TO LOWER THE 30 SECOND ; WAIT TO 20 SECONDS). ; RESULT: MVI C,60 ;<<== MAXIMUM TIME TO WAIT FOR RESULT SMWLP: PUSH B MVI B,1 ;CHECK FOR A CHAR, UP TO 1 SEC WAIT MVI C,TMDINP ;DO TIMED INPUT CALL MEX POP B CPI '*' ; parse the returned string for JZ SMTEST ; valid characters CPI 'O' ; if an abort JZ SMTEST CPI 'U' ; if it's busy JZ SMTEST CPI 'R' ; if it's ringing CZ RING ; IF DCD ;if DCD is available, take a look at it IN STPORT ; get the status byte ANI DCDBIT ; and test the DCD flag XRI DCDBIT ; return with A=0 if found, RZ ;but otherwise ... ENDIF ;DCD ; PUSH B ; TEST FOR CONTROL-C FROM CONSOLE MVI C,CHEKCC CALL MEX POP B JNZ SMNEXT ;IF NOT, JUMP MVI B,' ' ;YES, SHUT DOWN THE MODEM MVI C,SNDCHR ; NEC uses a space to abort dialing CALL MEX MVI A,3 ;RETURN ABORT CODE RET SMNEXT: DCR C ;NO JNZ SMWLP ;CONTINUE ; ; ONE MINUTE WITH NO MODEM RESPONSE (OR NO CONNECTION) ; SMTIMO: 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: POP PSW ;A HAS MEX RETURN-CODE, CY=1 IF UNKNOWN JC RESULT ;IF RESULT UNKNOWN, IGNORE IT RET ; SMANAL: MVI B,0 ;PREP CONNECT CODE CPI '*' ;"CONNECT"? (NEC "*ON LINE*") RZ INR B ;PREP BUSY CODE B=1 CPI 'U' RZ INR B ;PREP NO CONNECT MSG B=2 CPI 'O' ;N=NO CONNECT (NEC "AB'O'RT") RZ MVI B,4 ;PREP MODEM ERROR CPI 'O' ;E=ERROR (NEC "AB'O'RT") RZ STC ;UNKNOWN... RET ; RING: PUSH B ; is that the phone ? MVI C,ILP CALL MEX DB 'Ringing... ',0 POP B RET ; go back & find if successful ; ; FOLLOWING ROUTINE DISCONNECTS THE MODEM USING SMARTMODEM ; CODES. ALL REGISTERS ARE AVAILABLE FOR THIS FUNCTION. ; NOTHING RETURNED TO CALLER. ; This is not used in this implementation. However, if you do ; not use DTR to disconnect and you want to use this routine ; set the disconnect code in the NEC modem to this string (+++ath) ; or to whatever other string you desire. Be sure to change the ; string here to match the one you set in the modem. ; IF DISC ; DISCON: MVI B,20 MVI C,TIMER ;WAIT 2 SECONDS CALL MEX LXI H,SMATN ;SEND '+++' CALL SMSEND MVI B,20 ;WAIT 2 MORE SECONDS MVI C,TIMER CALL MEX LXI H,SMDISC ;SEND 'ATH' CALL SMSEND MVI B,1 ;WAIT 1 SECOND MVI C,TIMER CALL MEX RET ; SMATN: DB '+++',0 SMDISC: DB 'ATH',CR,0 ; ENDIF ; ; SMARTMODEM UTILITY ROUTINE: SEND STRING TO MODEM ; SMSEND: MVI C,SNDRDY ;WAIT FOR MODEM READY CALL MEX JNZ SMSEND MOV A,M ;FETCH NEXT CHARACTER INX H ORA A ;END? RZ ;DONE IF SO MOV B,A ;NO, POSITION FOR SENDING MVI C,SNDCHR ;NOPE, SEND THE CHARACTER CALL MEX JMP SMSEND ; ; DATA AREA ; DIALBF: DS 52 ;2 * 24 CHAR MAX, + CR + NULL + SLOP DIALPT: DS 2 ;DIAL POSITION POINTER ; END