; TRS-80 Model 4p internal modem overlay for MEX: revision 1.4 ; Originally written: 04/16/84 by Ronald G. Fowler (V1.0) ; ; 11/22/85: Changed all portions of this code that are strictly for the ; smartmodem so that this overlay will work with the TRS-80 ; Model 4p internal modem. (Bob Kitchen) ; ; The following notes are provided as information about the modification ; history of this overlay: ; ; 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 module adapts MEX for the TRS-80 Model 4p internal modem. The main ; function is to provide dialing capability; the disconnect vector is ; ancillary. You may use this module as a model to develop dialing routines ; for other Radio Shack modems. The only pertinent entry point is the DIAL ; routine; you'll find entry specs for that below. ; ; This overlay will work with any modem overlay that terminates prior to 0B00H ; FALSE EQU 0 TRUE EQU NOT FALSE ; ; SYSTEM CONSTANTS ; TPULSE EQU 0105H ;TONE/PULSE FLAG IN MODEM OVERLAY DIALV EQU 0162H ;LOCATION OF DIAL 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 ; ; 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 ; ; ; ; 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,'X' ;4P MODEM START DIAL CHARACTER INX H MVI M,CR ;STUFF END-OF-LINE INTO BUFFER INX H ;FOLLOWED BY TERMINATOR MVI M,0 LXI H,SMDIAL ;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 ; 30 SECONDS: YOU MAY CHANGE THIS VALUE IN THE FOLLOWING LINE). ; RESULT: MVI C,30 ;<<== 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 JNC SMTEST ;JUMP IF MODEM HAD A CHAR PUSH B ;NO, TEST FOR CONTROL-C FROM CONSOLE MVI C,CHEKCC CALL MEX POP B JNZ SMNEXT ;IF NOT, JUMP MVI B,CR ;YES, SHUT DOWN THE MODEM MVI C,SNDCHR CALL MEX MVI A,3 ;RETURN ABORT CODE RET SMNEXT: DCR C ;NO JNZ SMWLP ;CONTINUE ; ; ONE HALF 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 0AH ;4P MODEM CONNECT CODE RZ INR B ;PREP NO CONNECT CODE CPI 15H ;4P MODEM NO CONNECT CODE RZ STC ;UNKNOWN... RET ; ; 4P MODEM 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 ; SMDIAL: DB '*C*MG@',125,'DT' DIALBF: DS 52 ;2* 24 CHAR MAX, + CR + NULL + SLOP DIALPT: DS 2 ;DIAL POSITION POINTER ; END