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	; xor a
	4	; ld hl, $FF60
	5	; ld [hli], a
	6	; ld [hli], a
	7	; ld [hli], a
	8	st: ld sp, $CFFF
	9	nak:
	10	ld a, $15 ; NAK
	11	call putc+$FF80
	12
	13	.ack: call getc+$FF80
	14	; cp $01 ;SOH
	15	; jr z,.soh
	16	cp $04 ;EOT
	17	jr z, .eot
	18	cp $18 ;CAN
	19	jr z, .rst
	20	jr nak
	21
	22	.eot:
	23	ld A, $06 ; Ack the EOT
	24	call putc+$FF80
	25	.rst: rst $00
	26
	27	.soh: call getc+$FF80 ; blk
	28	call getc+$FF80 ; iblk
	29	ld b, $00
	30	ld hl, $C000
	31	.lp: bit 7, l
	32	jr nz, .cksm
	33	call getc+$FF80
	34	ld [hli], a
	35	add b
	36	ld b, a
	37	jr .lp
	38	.cksm: call getc+$FF80
	39	cp b
	40	jr nz, .donak
	41	ld hl, $C000
	42	.lp2: ld a, [hli]
	43	ld [$FF63], A
	44	bit 7, l
	45	jr z,.lp2
	46	.doack: ld A, $06 ; 06
	47	call putc+$FF80
	48	jr .ack
	49	.donak: call getc+$FF80 ; Wait until the line clears, and then once
	50	jr .donak ; that happens, getc will cause a NAK.
	51
	52	getc:
	53	xor d
	54	;xor e ; Possibly not needed?
	55	.dgetc:
	56	dec de
	57	xor a
	58	cp d
	59	jr z, .timeout
	60	ld a, [$FF53]
	61	and $02
	62	jr z, .dgetc
	63	ld a, [$FF52]
	64	ret
	65	.timeout:
	66	ld hl, $D010
	67	ld a, [hl]
	68	inc a
	69	ld [hl], a
	70	ld [$FF51], a
	71	pop hl
	72	jr nak
	73
	74	putc:
	75	ld c, $53
	76	push af
	77	.waitport:
	78	ld a,[c]
	79	and $01
	80	jr nz,.waitport
	81	pop af
	82	ld [$FF52],a
	83	ret
	84
	85	section "a", HOME[$7E]
	86	nop