;
;	PCPICLK.MAC
;
;	Z80 DateStamper clock driver for use with 6502 hardware
;	driver. Uses same convention for all Apple clocks. 
;
;	12/25/87 - sh.
;
;
;	*** NOTE *** CLKADD must be patched to the base address of
;	your running DateStamper(tm) system! This is displayed during
;	loading of the DS module. More information may be found in the
;	DateStamper manual Appendix 'B'.
;
;
CLKADD	EQU	0E395H		;patch this for your installation!
;
;
;
WR65WRD	EQU	0FFE9H		;write word to 6502
RD65BYT	EQU	0FFE0H		;read byte from 6502
RD65BLK	EQU	0FFECH		;read block from 6502
;
;
	.Z80
;
	ORG	80H
	DW	CLKLEN		;length of clock driver
	DW      0		;static year if needed
	DB	'PCPI Clk DVR'	;name of clock driver
;
;
	ORG	CLKADD
;
CLOCK:	LD	DE,16*256 + (14*4+0C3h)
				;command #16 to  char. dev. #14 'other'
	CALL	WR65WRD
;
	LD	DE,5
	CALL	RD65BLK		;read first five bytes
				;'hl' had the buffer address!
	LD	E,(HL)		;grab previous seconds
	CALL	RD65BYT		;now get new seconds
	LD	(HL),A		;and put in buffer
	RET
;
;
CLKLEN	EQU	$ - CLOCK	; should be <= 42H!

	END