mos6507's Blog

The chimera.h file and chimera_font.asm are missing in the archive.

Added via "includes.zip"

Added via "includes.zip"

Thanks!

 

Now define "gapless". Do you want to get rid of the vertical stripes?

In this kernel the text drawing area is effectively 7-bits because of how it's using the HMOVE fine control to shift the sprites back and forth on every line. As Supercat stated, you'd have to exploit the behavior of hitting HMOVE on cycle 74 to get +/-8 pixels. And to do this you have to remove the WSYNC and perfectly time the kernel. I haven't had time to hack at this.

And to do this you have to remove the WSYNC and perfectly time the kernel.

That's far too easy for a free Chimera.

println
;-------------------------
;...
;---------------------------------------------------
ldx	 #4
sta	 WSYNC
pause
nop
dex
bne	 pause
lda	 temp
lda	 temp

sta	 HMCLR
ldx	 #$80			   ;	   +8
ldy	 #FONTHEIGHT		;	  
lda	 frame
and	 #$01
beq	 oddFrame
jmp	 evenFrame

;THIS IS IT
print1
sta	 GRP1			   ; 3
lda	 CH_QUEUE_FAST+4	; 4		 
sta.w   GRP0			   ; 4
lda	 CH_QUEUE_FAST+6	; 4		 
stx.w   HMP0			   ; 4
stx	 HMP1			   ; 3
sta	 GRP1			   ; 3
lda	 CH_QUEUE_FAST+8	; 4		 
sta.w   GRP0			   ; 4
lda	 CH_QUEUE_FAST+10   ; 4		 
sta.w   GRP1			   ; 4
sta	 GRP0			   ; 3
evenFrame					  ;	   @50
dey						; 2
bmi	 wrapEven		   ; 2³
lda	 CH_QUEUE_FAST+1	; 4		 
nop						; 2
sta.w   GRP0			   ; 4
lda	 CH_QUEUE_FAST+3	; 4		 
nop						; 2
nop						; 2
sta	 GRP1			   ; 3
;---------------------------------------
sta	 HMOVE			  ; 3	 @02
lda	 CH_QUEUE_FAST+5	; 4		 
nop						; 2
sta.w   GRP0			   ; 4
lda	 CH_QUEUE_FAST+9	; 4		 
nop						; 2
sta.w   temp			   ; 4
lda	 CH_QUEUE_FAST+7	; 4		 
nop						; 2
sta.w   GRP1			   ; 4
lda	 temp			   ; 3
sta	 GRP0			   ; 3
lda	 CH_QUEUE_FAST+11   ; 4		 
nop						; 2
sta.w   GRP1			   ; 4

oddFrame					   ;	   @48
sta	 GRP0			   ; 3
lda	 #$00			   ; 2	 -8
sta	 HMP0			   ; 3
sta	 HMP1			   ; 3
dey						; 2
bmi	 wrapOdd			; 2³
lda	 CH_QUEUE_FAST+0	; 4		 
sta	 GRP0			   ; 4
;---------------------------------------
sta	 HMOVE			  ; 4	 @73
nop
lda	 CH_QUEUE_FAST+2	; 4		 

  ;THIS IS IT

jmp	 print1			 ; 3

And to do this you have to remove the WSYNC and perfectly time the kernel.

That's far too easy for a free Chimera.

 

Thanks so much, Thomas! I'll try that out when I get home.

 

If that's too easy, though, you could try converting other kernels. The next on the list is Suicide Mission.

If that's too easy, though, you could try converting other kernels. The next on the list is Suicide Mission.

What exactly should I convert there? The title screen?

You'd pull the portion of the code out that displays the in-game bitmap and instead of pulling data from Supercharger RAM, have it just read from the queue hotspots.

 

This could throw off the timing in the kernel depending on the addressing modes used.

 

So you'd wind up with a vanilla 4K program that displays the Suicide Mission kernel but the graphics don't change on every line. When run on an emulator you'd just hardcode FFs into the queue hotspots to verify that the kernel works. That's what I did with the text kernel. The text kernel just shows solid blocks on an emulator.

 

If the RAM overhead is small enough it might be possible to do a chronocolor effect with Suicide Mission. There is only 4K of ARM RAM reserved for bitmaps.

This could throw off the timing in the kernel depending on the addressing modes used.

Which should be pretty easy to fix.

 

So you'd wind up with a vanilla 4K program that displays the Suicide Mission kernel but the graphics don't change on every line.

Sounds simple enough.