; B3AM-0.INS - AMPRO "Little Board" insert for BYE3 - 06/10/85
;
; DART I/O and CTC timer 2.000 MHz
;
; Note: This is an insert, not an overlay.
;
; This version is for the AMPRO "Little Board" using channel "B" of the
; Z80 DART. The Z80-CTC is used as the baud rate generator.
;
; The AMPRO computer does not implement DTR or DCD
; (CTS and RTS are used instead).
;
; Make up a RS232 cable per the instructions below:
;
; Modem Ampro
; ----- -----
; pin 1 - pin 1
; pin 2 - pin 3
; pin 3 - pin 2
; pin 6 - pin 20
; pin 7 - pin 7
; pin 20 - pin 5
;
; Note: These pin assignments assume that your Little Board RS232 female
; connector is wired the same as the Ampro assembled computers.
;
;
; = = = = = = = = = = = = = = = = = =
;
; 06/10/85 Written for use with BEE335 and later - Irv Hoff
; 02/08/84 Initial Version Jerry Haigwood
;
; = = = = = = = = = = = = = = = = = =
;
;-----------------------------------------------------------------------
;
;
PORT EQU 88H ; Data port
MDCTL1 EQU PORT+4 ; Status/control port
BRPORT EQU 50H ; Baud rate port
;
;
BD300: DW 47D0H ; 62400/300 (first half is CTC command)
BD1200: DW 4734H ; 62400/1200
BD2400: DW 471AH ; 62400/2400
;
;
;-----------------------------------------------------------------------
;
; See if we still have a carrier - if not, return with the zero flag set
;
MDCARCK:MVI A,10H ; Reset status
OUT MDCTL1
IN MDCTL1 ; Get status
ANI 20H ; Check for data carrier
RET
;.....
;
;
; Disconnect and wait for an incoming call
;
MDINIT: MVI A,18H ; Reset channel
OUT MDCTL1
MVI A,4 ; Setup to write register 4
OUT MDCTL1
MVI A,84H ;*1 stop, 8 bits, no parity, 32x
OUT MDCTL1
MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,68H ; Clear RTS causing hangup
OUT MDCTL1
PUSH B ; Save in case it's being used elsewhere
MVI B,20 ; 2 seconds delay to drop any carrier
;
OFFTI: CALL DELAY ; 0.1 second delay
DCR B
JNZ OFFTI ; Keep looping until finished
POP B ; Restore bc
MVI A,3 ; Setup to write register 3
OUT MDCTL1
MVI A,0C1H ; Initialize receive register
OUT MDCTL1
MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,0EAH ; Turn on RTS so modem can answer phone
OUT MDCTL1
;
IF IMODEM ; If using intelligent modem
CALL IMINIT ; Go initialize
ENDIF ; IMODEM
;
RET
;.....
;
;
; Input a character from the modem port
;
MDINP: IN PORT ; Get character
ANI 7FH ; Strip parity
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 01H ; Check receive ready bit
RZ ; Return if none
ORI 0FFH ; Otherwise, set the proper flag
RET
;.....
;
;
; Send a character to the modem
;
MDOUTP: OUT PORT ; Send it
RET
;.....
;
;
; See if the output is ready for another character
;
MDOUTST:IN MDCTL1
ANI 04H ; Check transmit ready bit
RET
;.....
;
;
; Reinitialize the modem and hang up the phone by dropping DTR and
; leaving it inactive.
;
MDQUIT: IF IMODEM ; If using a smartmodem
CALL IMQUIT ; Tell it to shut down
ENDIF ; IMODEM
;
;
; Called by the main program after caller types BYE
;
MDSTOP: MVI A,5 ; Setup to write register 5
OUT MDCTL1
MVI A,68H ; Clear RTS causing shutdown
OUT MDCTL1
RET
;.....
;
;
; The following routine sets the baudrate. BYE3 asks for the maximum
; speed you have available.
;
SETINV: ORI 0FFH ; Make sure zero flag is not set
RET ; Return
;.....
;
;
SET300: LHLD BD300 ; Get 300 bps parameters in 'HL'
JMP LOADBD ; Go load them
;
SET1200:LHLD BD1200
JMP LOADBD
;
SET2400:LHLD BD2400
;
LOADBD: MOV A,H ; CTC command word
STA BRPORT
MOV A,L ; Baudrate
STA BRPORT
RET
;.....
;
; end
;-----------------------------------------------------------------------
