Eckhard Stolberg wrote:
> At 18:38 02.08.99 -0700, you wrote:
>
> >however, i am still somewhat puzzled about the
> >other thing...when the paddle is turned clockwise, INPT#
> >bit 7 is supposed to take more cycles before bit 7 is
> >set to one, right?
>
> This is correct. It is a bit difficult to say what's wrong with your
> code without beeing able to see all of it, but in the other post you
> mentioned having a LDA INPTx/BMI/INC loop. That would mean that the
> counter value would get bigger the further the paddle is turned clockwise.
> If you want to position your object further down the screen the higher
> the counter is, then the reference counter in the display routine must
> count upwards too. Are you sure your display routine does this? ;-)
are you referring to the scanline counter? because in
the code, Y pretty much serves as the scanline counter
until all but the bottommost line is drawn...and it is
incremented in every scanline before WSYNC...the code
doesn't actually execute until below the score display,
and until it executes, the paddles are not tracked.
here is the snippet of my code that is the display
routine...i have a seperate routine for my first
scanline because of the fact that it comes immediately
after a line that uses #$FF on the playfield regs to
make a top border...this routine doesnt actually
execute until the second scanline in the "playground",
which is where the missiles and ball are at. what it
does is basically evaluates the scanline versus the
start and end positions of the missiles and ball, and
then acts on them, then checks the paddles for bit 7
set, and increments the potentiometer counters if bit 7
has not been set...and then increments Y and determines if
the last line has yet to be reached...and so on...
; CONTINUEPLAYGROUNDDISPLAY
; Main display routine for missiles and ball (below score and top border)
; This is executed on the second scanline in the playground
; $DA, $DB - Ball start and end Y positions
; $DC, $DD - Missile 0 start and end Y positions
; $DE, $DF - Missile 1 start and end Y positions
SUB1 STA WSYNC
CPY $DA
BCC SUB2
CPY $DB
BCS SUB2
STX ENABL
CPY $DC
BCC SUB3
CPY $DD
BCS SUB3
STX ENAM0
CPY $DE
BCC NEXTA
CPY $DF
BCS NEXTA
STX ENAM1
JMP NEXT
SUB2 STA ENABL
CPY $DC
BCC SUB3
CPY $DD
BCS SUB3
STX ENAM0
CPY $DE
BCC NEXTA
CPY $DF
BCS NEXTA
STX ENAM1
JMP NEXT
SUB3 STA ENAM0
CPY $DE
BCC NEXTA
CPY $DF
BCS NEXTA
STX ENAM1
JMP NEXT
NEXTA STA ENAM1
NEXT LDA INPT0
BMI PAD1
INC $C0
PAD1 LDA INPT1
BMI INIT
INC $C1
; A few odds and ends to sort out before the next scanline
INIT
INY
CPY #$AB
BNE SUB1
STA WSYNC
this is the code that is executed during overscan and turns
off the paddles and all objects, then whatever value is
stored in $C0 and $C1 is put in the start Y position variables,
and those same values plus 15 are stored in the end position
variables.
LDX #$82
STX VBLANK ; Turn on vertical blank and turn off paddles
LDA #$00
STA PF0 ; Disable all objects in case they havent been
STA PF1 ; already turned off somewhere in the display
STA PF2
STA ENAM0
STA ENAM1
STA ENABL
LDA $C0
STA $DC
CLC
ADC #$15
STA $DD
LDA $C1
STA $DE
CLC
ADC #$15
STA $DF
JMP VLOOP ; This takes us back to initialization procedures
if you need the whole code, ill post it. keep in mind this
code is merely an alpha version.
dee
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