Joshua Wise's Git repositories - fpgaboy.git/blame_incremental

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Commit	Line	Data
	1	SECTION "wee",HOME[$0]
	2	; this all needs to be PIC!
	3	st:
	4	ld sp, $CFFF
	5	xor a
	6	ld hl, $FF60
	7	ld [hli], a
	8	ld [hli], a
	9	ld [hli], a
	10	nak:
	11	ld a, $15 ; NAK
	12	call putc+$FF80
	13
	14	.ack: call getc+$FF80
	15	cp $01 ;SOH
	16	jr z,.soh
	17	cp $04 ;EOT
	18	jr z, .eot
	19	cp $18 ;CAN
	20	jr z, .rst
	21	jr .donak
	22
	23	.eot:
	24	ld A, $06 ; Ack the EOT
	25	call putc+$FF80
	26	.rst: rst $00
	27
	28	.soh: call getc+$FF80 ; blk
	29	call getc+$FF80 ; iblk
	30	xor a
	31	ld b, a
	32	ld l, a
	33	ld h, $C0
	34	.lp: call getc+$FF80
	35	ld [hli], a
	36	add b
	37	ld b, a
	38	bit 7, l
	39	jr z, .lp
	40	.cksm: call getc+$FF80
	41	cp b
	42	jr nz, .donak
	43	ld hl, $C000
	44	.lp2: jr z, .doack
	45	ld a, [hli]
	46	ld [$FF63], A
	47	bit 7, l
	48	jr z,.lp2
	49	.doack: ld A, $06
	50	call putc+$FF80
	51	jr .ack
	52	.donak: call getc+$FF80 ; Wait until the line clears, and then once
	53	jr .donak ; that happens, getc will cause a NAK.
	54
	55	getc:
	56	xor d
	57	xor e
	58	.dgetc:
	59	dec de
	60	xor a
	61	cp d
	62	jr z, .timeout
	63	ld a, [$FF53]
	64	and $02
	65	jr z, .dgetc
	66	ld a, [$FF52]
	67	ret
	68	.timeout:
	69	ld hl, $D000
	70	ld a, [hl]
	71	inc a
	72	ld [hl], a
	73	ld [$FF51], a
	74	jr nak
	75
	76	putc:
	77	ld c, $53
	78	push af
	79	.waitport:
	80	ld a,[c]
	81	and $01
	82	jr nz,.waitport
	83	pop af
	84	ld [$FF52],a
	85	ret
	86
	87	section "a", HOME[$7F]
	88	nop