Differences

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--- playground:playground [2022-03-11 22:24] – erhan
+++ playground:playground [2022-03-11 22:46] – old revision restored (2015-10-03 14:50) erhan
@@ Line 1: / Line 1: @@
-====== Scanning the keyboard without joysticks interfere ======
+====== PlayGround ======
-Converts keycode ($00-$3F) to $DC00-$DC01 values and scans without interfering from joysticks at port 1 or 2. Also keeps history, to detect key press & hold.
-<code>
-;64tass format
-;with default $dc02 - $dc03 values ($ff and $00)
-;taken from Platoon game, shortened and key history integrated.
-;code to key conversion table below, from c64-wiki.com
-;to use inside irq, below code is enough :
-;	lda #$keycode
-;	jsr keyscan
-;	bcc +
-;	inc $d020
-;+	rts
-;$00	Inst/Del	$10	5	$20	9	$30	£
-;$01	Return		$11	R	$21	I	$31	*
-;$02	Crsr ←→		$12	D	$22	J	$32	]
-;$03	F7/F8		$13	6	$23	0	$33	Clr/Home
-;$04	F1/F2		$14	C	$24	M	$34	R.Shift
-;$05	F3/F4		$15	F	$25	K	$35	=
-;$06	F5/F6		$16	T	$26	O	$36	↑
-;$07	Crsr ↑↓		$17	X	$27	N	$37	?
-;$08	3		$18	7	$28	+	$38	1
-;$09	W		$19	Y	$29	P	$39	←
-;$0A	A		$1A	G	$2A	L	$3A	Ctrl
-;$0B	4		$1B	8	$2B	−	$3B	2
-;$0C	Z		$1C	B	$2C	>	$3C	Space
-;$0D	S		$1D	H	$2D	[	$3D	Commodore
-;$0E	E		$1E	U	$2E	@	$3E	Q
-;$0F	L.Shift		$1F	V	$2F	<	$3F	Run/Stop
-	* = $1000
-	lda #$3e		;scan for key "Q"
-	jsr keyscan
-	bcc +
-	inc $d020		;C=1, this code executed if key is pressed
-+
--	lda $d011
-	bpl -
--	lda $d011
-	bmi -
-	jmp $1000
-keyscan
-;	sty backy+1		;remove comment if you need .Y preserved
-	pha
-	lsr
-	lsr
-	lsr
-	tay
-	lda row,y
-	sta $dc00
-	pla
-	and #$07
-	tay
-	lda $dc01
-	and column,y
-	bne nokey
-	lda #$ff		;key is checked 2nd time, to be sure of
-	sta $dc00		;joy #1 and #2 are not interfering
-	lda $dc01
-	and column,y
-	beq nokey
-	cmp histv		;history value ?
-	bne +
-	clc		        ;case #3, key is held down. keep history & set C=0
-	bcc backy
-nokey	asl			;case #1, no keypress, update history value 2x & set C=0
-	clc
-	.byte $24
-+	sec			;case #2, key pressed&released. update history & set C=1
-	sta histv
-backy
-;	ldy #$00		;remove comment if you need .Y preserved
-	lda #$ff
-	sta $dc00		;set default value
-	lda #$7f
-	sta $dc01		;set default value
-	rts
-row	.byte $fe,$fd,$fb,$f7,$ef,$df,$bf,$7f
-column	.byte $01,$02,$04,$08,$10,$20,$40,$80
-histv	.byte $00
-</code>