Here is the code from JoustPong. I'm not clever enough
by half to come up with this on my own, I think I was
led by the hand by Andrew Davies. It positions the ball.
About the "battlezone" code, before it starts, what value
needs to be set to the horizontal position of the object?
;--------------------------------------
;SET BALL HORIZONTAL POSITION
;--------------------------------------
sta HMCLR ; clear any previous movement
sta WSYNC
lda ballXposition
;;;set rough adjustment to Y and fine adjustment to A
;;;math magic to divide ballXposition by 15 by dividing
;;;by 16 and then....magic!
tay
lsr ; divide by 2
lsr ; again
lsr ; again
lsr ; again
sta tempVar
tya
and #15
clc
adc tempVar
ldy tempVar
cmp #15
bcc NoBallHangover
sbc #15
iny
NoBallHangover
;do fine adjusment
eor #7
asl
asl
asl
asl
sta HMBL
sta WSYNC
SLEEP 15
DelayRoughPos
dey
bpl DelayRoughPos
sta RESBL
--
KirkIsrael@xxxxxxxxxxxxx http://kisrael.com
"It's the cracked ones who let all the light into the world."
--writer from my Tufts writing class
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