; B3AP-2.INS - APPLE ][ with Mountain CPS Serial Card - 07/30/85
;
; 2651 with internal baudrate generator
;
; NOTE: This is an insert, not an overlay.
;
; WARNING: Carrier detect (DCD) from the modem must go to DSR input on
; the 2651 to provide proper operation for both autodialing
; and autoreceiving. If you use the DCD input, it requires
; voltage (normally unavailable) during dialing to allow
; result codes to be used.
;
; To build "a better modem cable", on the apple side of the cable,
; hook the following pins together:
; 5, 8, 20 - this will force CTS and DCD high when
; DTR is on.
; 6 - tie the real DCD (pin 8 on the modem)
; to this pin.
;
; This program assumes you use the DSR pin (80H) to check carrier
; from the modem.
;
; = = = = = = = = = = = = = = = = = =
;
; 07/30/85 Restored original format - pst
; 07/24/85 Fixed minor bug with 2400 baud setting - pst
; 01/20/84 Created overlay using BY2-2651.ASM - Norman Beeler
;
; = = = = = = = = = = = = = = = = = =
;
; Define the CPS card slot you are using (normally 1 or 2)
;
SLOT EQU 2 ; CPM card slot
;
;=======================================================================
;
; Modem port equates
;
DPORT EQU 0E0FAH+SLOT*100H ; Modem data port
SPORT EQU 0E0FBH+SLOT*100H ; Modem status port
XPORT EQU 0E0FEH+SLOT*100H ; Modem swap port
;
; Status port equates
;
TBMT EQU 00000001B ; Transmit buffer empty
DAV EQU 00000010B ; Data available
DCD EQU 10000000B ; Data carrier detect
;
; Mode port equates
;
EBASE EQU 30H ; Mode register 2 base
B300 EQU EBASE+5 ; 300 baud
B1200 EQU EBASE+7 ; 1200 bps
B2400 EQU EBASE+10 ; 2400 bps
;
;-----------------------------------------------------------------------
;
; See if we still have a carrier - if not, return with the zero flag set
;
MDCARCK:LDA SPORT ; Read port
ANI DCD ; Check DSR for carrier (do not use DCD)
RZ
ORI 255
RET
;
; Disconnect and wait for an incoming call
;
MDINIT: MVI A,80H ; Open CPS command register
STA XPORT ; By storing 80H in XPORT
MVI A,15H ; Turn DTR off, modem will quit
STA SPORT
MVI B,20 ; 2 seconds to drop any carrier
;
MDINIT1:CALL DELAY ; .1 second delay
DCR B
JNZ MDINIT1
MVI A,17H ; With DTR on, modem accepts commands
STA SPORT
XRA A ; Close the command port
STA XPORT ; By storing 0 in XPORT
;
IF IMODEM
CALL IMINIT ; Initialize smartmodem
ENDIF ; IMODEM
;
RET
;
; Input a character from the modem port
;
MDINP: LDA DPORT ; 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: LDA SPORT ; Read port
ANI DAV ; Check receive ready bit
RZ ; Nope, nothing there
ORI 255 ; We got something...
RET
;
; Send a character to the modem
;
MDOUTP: STA DPORT ; Send it
RET
;
; See if the output is ready for another character
;
MDOUTST:LDA SPORT ; Read port
ANI TBMT ; Check transmit ready bit
RZ
ORI 255
RET
;
; Reinitialize the modem and hang up the phone by dropping DTR and
; leaving it inactive.
;
MDQUIT: IF IMODEM
CALL IMQUIT ; Initialize modem to default settings
ENDIF ; IF IMODEM
;
;
; Called by the main program after caller types BYE
;
MDSTOP: MVI A,80H ; Open CPS command register
STA XPORT ; By storing 80H in XPORT
XRA A ; Turn DTR off, modem will quit
STA SPORT
CALL DELAY ; Let it stabilize
RET
;
; The following routine sets the baudrate. BYE3 asks for the maximum
; speed you have available.
;
SET300: CALL BSETUP
MVI A,B300
JMP FSETUP
;
SET1200:CALL BSETUP
MVI A,B1200
JMP FSETUP
;
SET2400:CALL BSETUP
MVI A,B2400
JMP FSETUP
;
BSETUP: MVI A,80H
STA XPORT
MVI A,37H ; Initialize the serial chip
STA SPORT ; By storing 37H in SPORT
MVI A,4EH ; 1 stop, 8 bits, no parity
STA DPORT
XRA A
RET
;
FSETUP: STA DPORT
XRA A
STA XPORT ; Close command port by storing 0
RET
; end
;-----------------------------------------------------------------------
