Re: 65816ASM - SHR question included.

[jpenne@ee.ualberta.ca (Jerry Penner)]

yoshi@atlantis.CS.ORST.EDU (Yoshi Tagawa) writes:

>It seems that if I change a pallate-colour-entry right after checking
>the keyboard, the actual desired routine will activate, but the graphics
>updation doesn't update until the SECOND time you hit the key.

>(Note: This is ORCA, not Merlin. Blech. :)).
>((I'm sure this code isn't correct, but im not going to actually show my
>  code here. HMPH! J/K!)).

The problem seems to be that you're reading the keyboard with the M
flag clear (ie. 16-bit accumulator/memory).  You should be doing a SEP
#$20 before reading the keyboard and a REP #$20 after clearing the
keyboard strobe.

nuke this	>KB	lda >$E1C000

KB	sep #$20

>	bpl KB
>	sta >$E1C010

	rep #$20

>	cmp #$C1			; Check for "A" key.
>	bne KB

>	lda #$600
>	sta >$E19E48			; Turn Pal.2, colour #4 dark-red.

>	lda #$F00
>	sta >$E19E4A			; Turn pal.2, color #5 bright-red.

>	jsr StopMusic			; Stop music.
>	jmp KB

>OK, so, what happens is I have to hit "A" twice in a row before the
>actual PALLATE COLOUR changes. The music will stop the first time around,
>but then the result becomes when the music is on, the wrong colour is
>in the wrong place.
>	Is this because of my Keyboard Buffer: Yes setting, or is
>it my code? I've been trying to figure out the deal for the last 45
>minutes, and i'm stuck. Dave Huang, where are you! :)

Hopefully that's the fix.  If it's not, I'm kind of stumped unless I
see your real code.
-- 
Jerry Penner   jpenne@ee.ualberta.ca   or   jjp@myrias.ab.ca