; B5DP-1.INS - BYE5 insert for Datapoint 1560 - 07/17/85 ; ; 8251A and 8430 CTC timer 3.6864 MHz ; ; Note: This is an insert, not an overlay ; ; = = = = = = = = = = = = = = = = = = ; ; 07/17/85 Written to work with BYE5 - Irv Hoff ; ; = = = = = = = = = = = = = = = = = = ; ; ; The following define the port addresses to use ; PORT EQU 28H ; Modem base port MDCTL1 EQU PORT+1 ; Modem control port RCVPORT EQU 20H ; Receive speed CTC port XMTPORT EQU 1AH ; Transmit speed CTC port ; MDRCV EQU 2 ; Modem receive ready bit MDSND EQU 1 ; Modem send ready bit RESET EQU 38H ; Framing, overrun and parity errors ; MDMODE EQU 82H ; Insures 8251 is out of mode, DTR high MDRSET EQU 42H ; Resets USART for additional commands MDSET1 EQU 4EH ; 1 stop bit, no parity, 8 bits, x16 MDSET2 EQU 0CEH ; 2 stop bits, no parity, 8 bits, x16 ; ; ; The following are CTC timer baud rates divisors. ; BD300 EQU 32 ; 9600/300 = 300 bps BD1200 EQU 8 ; 9600/1200 = 1200 bps BD2400 EQU 4 ; 9600/2400 = 2400 bps ; ; ;----------------------------------------------------------------------- ; ; See if we still have a carrier - if not, return with the zero flag set ; MDCARCK:IN MDCTL1 ; Get status ANI 80H ; Check DSR for carrier from modem RET ;..... ; ; ; Disconnect and wait for an incoming call. ; MDINIT: MVI A,10H ; Clear DTR OUT MDCTL1 ; Causing hangup PUSH B ; Preserve in case we need it MVI B,20 ; 2 seconds to drop DTR OFFTI: CALL DELAY ; 0.1 second delay DCR B JNZ OFFTI ; Keep waiting until carrier drops POP B ; Restore BC MVI A,MDMODE ; Insure 8251 is out of mode OUT MDCTL1 XTHL ; Delay a little XTHL ; Delay a little MVI A,MDRSET ; Reset the 8251A for new command OUT MDCTL1 XTHL XTHL MVI A,MDSET1 ; Set stop pulse, no parity 8 bits, x16 OUT MDCTL1 XTHL XTHL MVI A,17H ; Reset error flags, RCV, DTR, TX ready OUT MDCTL1 XTHL XTHL ; IF IMODEM CALL IMINIT ; Initialize smartmodem ENDIF ; IMODEM ; RET ;..... ; ; ; Input a character from the modem port ; MDINP: IN PORT ; Get character RET ;..... ; ; ; Check the status to see if a character is available. if not, return ; with the zero flag set. If yes, use 0FFH to clear the flag. ; MDINST: IN MDCTL1 ; Get status ANI MDRCV ; Got a character? RZ ; Return if none IN MDCTL1 ; Get status again ANI RESET ; Check for framing and overrun JZ MDINST1 ; No errors MVI A,17H ; Reset error flags OUT MDCTL1 XRA A ; Return false RET ;... ; ; MDINST1:ORI 0FFH ; We have a character RET ;..... ; ; ; Send a character t the modem ; MDOUTP: OUT PORT ; Send it RET ;..... ; ; ; See if the output is ready for another character ; MDOUTST:IN MDCTL1 ANI MDSND RET ;..... ; ; ; Renitialize the modem and hang up the phone by dropping DTR and ; leaving it inactive. ; MDQUIT: IF IMODEM CALL IMQUIT ENDIF ; IMODEM ; ; ; Called by the main program after caller types BYE ; MDSTOP: MVI A,10H ; DTR low hangs up phone, keep DTR low OUT MDCTL1 ; so will not auto-answer at any time RET ;..... ; ; ; The following routine sets the baudrte. BYE5 asks for the maximum ; speed you have available. ; SETINV: MVI A,0FFH ORA A ; Make sure the Zero flag isn't set RET ;..... ; ; SET300: MVI B,BD300 ; Load 300 baud JMP SETSPD ; SET1200:MVI B,BD1200 ; Poke in 1200 bps JMP SETSPD ; SET2400:MVI B,BD2400 ; Load 1200 bps ; SETSPD: MVI A,47H ; First byte of baudrate OUT RCVPORT OUT XMTPORT MOV A,B ; Second byte of baudrate OUT RCVPORT OUT XMTPORT XRA A ; Say it is ok RET ;..... ; ; end ;-----------------------------------------------------------------------