;
; This is an interrupt driven clock routine that
; uses an interrupt to increment the hour, minute and
; seconds registers in a real time clock.
;
	maclib	z80
	maclib	exec
;
;
cr	equ	0dh
lf	equ	0ah
esc	equ	01bh
;
	mvi	c,inln$chn	; Inline text print
	rst	1
	db	cr,lf,'Real time clock. Interrupt Serviced'
	db	cr,lf,'    By Richard Holmes  10/01/1988'
	db	cr,lf
	db	0
;
	mvi	a,0ffh		; An impossible time to compae to
	sta	old$sec
	xra	a
	sta	bel$flg
;
;
;
time:
	mvi	c,wdog
	rst	1
	mvi	c,ist$chn
	rst	1
	jz	time1
	mvi	c,inp$chn	; Get the character
	rst	1
	cpi	esc
	jz	quit		; Exit if an escape
;
	mvi	c,caps
	rst	1		; Capitalize the accumulator
	cpi	'S'
	jnz	time1
	cpi	'B'
	jmp	toggle$Bell
;
	mvi	c,inln$chn
	rst	1
	db	cr,lf
	db	cr,lf
	db	'Enter Hour : ',0
;
	mvi	c,idhl$chn	; Input decimal HL
	rst	1
	mov	a,l
	sta	hrs
;
	mvi	c,inln$chn
	rst	1
	db	cr,lf
	db	'Enter Mins : ',0
;
	mvi	c,idhl$chn	; Input decimal HL
	rst	1
	mov	a,l
	sta	min
;
	mvi	c,inln$chn
	rst	1
	db	cr,lf
	db	'Enter Secs : ',0
;
	mvi	c,idhl$chn	; Input decimal HL
	rst	1
	mov	a,l
	sta	sec
;
	lxi	d,hrs
	mvi	c,put$clk
	rst	1
;
;
time$1:
	lxi	d,hrs		;-> base of ram to be loaded
	mvi	c,get$clk	;   read clock to ram function
	rst	1
	lda	old$sec		; Compare to previous second
	mov	e,a
	lda	sec
	cmp	e
	jz	time
;
	sta	old$sec
;
; Print the time now.
	mvi	a,6		; LCD
	mvi	c,sel$chn
	rst	1
;
	mvi	c,xyin$chn	; Print the time message
	rst	1
	db	20,00,'Time : ',0
;
	lda	hrs
	mvi	c,pdac$chn
	rst	1
	mvi	a,':'
	mvi	c,out$chn
	rst	1
;
	lda	min
	mvi	c,pdac$chn
	rst	1
	mvi	a,':'
	mvi	c,out$chn
	rst	1
;
	lda	sec
	mvi	c,pdac$chn
	rst	1
;
	mvi	a,1
	mvi	c,sel$chn
	rst	1
;
; Decide if a peep of the bell
;
	lda	bel$flg
	ora	a
	jz	time			; Bel flg = 0 for no beeps
;
	lda	sec
	cpi	58
	jz	peep20
	cpi	59
	jz	peep20
	cpi	00		; On zero, a large peep
	jnz	time
;
	mvi	c,set$bel
	rst	1
;
	lxi	d,150
	mvi	c,delay
	rst	1
	mvi	c,clr$bel
	rst	1
	jmp	time
;
peep20:
	mvi	c,set$bel
	rst	1
	lxi	d,50
	mvi	c,delay
	rst	1
	mvi	c,clr$bel
	rst	1
	jmp	time
;
quit:
	mvi	a,1
	mvi	c,sel$chn
	rst	1
	jmp	3
;
toggle$bell:
	lda	bel$flg
	xri	1
	sta	bel$flg
	jmp	time

	dseg
;
bel$flg	ds	1
old$sec	ds	1
;
hrs	ds	1
min	ds	1
sec	ds	1
;
;
	end
;
;