;

      TITLE ZMAP-1.Z80 - 01/01/88 - ZMD I/O Overlay for APPLE II/MCPS
;				    Copyrighted (c) 1987, 1988
;				    Robert W. Kramer III

	PAGE
;-									 -;
;                         Update History                                  ;
;                                                                         ;
;    Date	Release			     Comments                     ;
;  --------	-------	  ----------------------------------------------  ;
;                                                                         ;
;  01/01/88	v1.00	- Initial version				  ;
;-                                                                       -;

;
SLOT	EQU	2		; CPS slot number, usually 1 or 2 
MODCR	EQU	0E0FEH+SLOT*100H ; Control port of CPS card
MODDATP EQU	0E0FAH+SLOT*100H ; Data port of CPS card
MODCTL1 EQU	0E0FBH+SLOT*100H ; Status port of CPS card
MODRCVB EQU	02H		; Bit to test for receive
MODRCVR EQU	02H		; Value when ready
MODSNDB EQU	01H		; Bit to test for send
MODSNDR EQU	01H		; Value when ready
MODDCDB EQU	01000000B	; Carrier detect bit
MODDCDA EQU	01000000B	; Value when active
MODPARE EQU	00001000B	; Parity error
MODOVRE EQU	00010000B	; Overrun error
MODFRME EQU	00100000B	; Framing error	

;
;-------------------------------------------------------------------------;
; Input/Output Jump Table						  |
;-------------------------------------------------------------------------;
;

	ORG	0580H		; Start after configuration table

	JP	0000H		; See CONOUT.INF
	JP	INIT		; Initialization routine
	JP	UNINIT		; Unititialize routine
	JP	SNDCHR		; Send character
	JP	CARCHK		; Test for carrier
	JP	GETCHR		; Get character from modem
	JP	RCVRDY		; Check receive ready
	JP	SNDRDY		; Check send ready

;
;-------------------------------------------------------------------------;
; System startup inititialization routine				  |
;-------------------------------------------------------------------------;

INIT:	RET

;
;-------------------------------------------------------------------------;
; System exit unititialization routine					  |
;-------------------------------------------------------------------------;

UNINIT:	RET

;
;-------------------------------------------------------------------------;
; Send character out modem						  |
;-------------------------------------------------------------------------;

SNDCHR:	POP	AF		; Get the character back
	LD	(MODDATP),A	; Send it to the modem output
	RET

;
;-------------------------------------------------------------------------;
; Check for carrier							  |
;-------------------------------------------------------------------------;

CARCHK:	LD	A,(MODCTL1)	; Read modem status port
	AND	MODDCDB		; Get carrier detect bit
	CP	MODDCDA		; Test bit
	RET

;
;-------------------------------------------------------------------------;
; Get character from modem						  |
;-------------------------------------------------------------------------;

GETCHR:	LD	A,(MODDATP)	; Get character from data in port 
	RET

;
;-------------------------------------------------------------------------;
; Check modem receive ready						  |
;-------------------------------------------------------------------------;

RCVRDY:	LD	A,(MODCTL1)	; Get modem status
	AND	MODRCVB		; Isolate ready bit
	CP	MODRCVR		; Test it
	LD	A,0		; Return with zero in A (so MB-KMD doesn't
	RET			; Think we have an error)

;
;-------------------------------------------------------------------------;
; Check modem send ready						  |
;-------------------------------------------------------------------------;

SNDRDY:	LD	A,(MODCTL1)	; Read status port
	AND	MODSNDB		; Mask off bit to be tested
	CP	MODSNDR		; Set status flag
	RET


	END