Blitz2: Hires laced

[clenched]

bippym - This works on A500 but not A1200 (both WinUAE). $DFF004 register is not behaving as expected with AGA. With ECS it rapidly switches between $A000 & $2000. AGA is stuck on $A300. Since your program is using that register*, that may be why the display isn't switching properly.
* assumed typo in listing

BLITZ
BitMap 0,640,512,3
SetBPLCON0 4
Slice 0,44,640,256,$fffb,3,8,8,1280,1280
RGB 0,5,5,5
RGB 1,15,15,15

SetInt 5
  x=0
  TST.w $dff004
  BMI skip
  x=1
skip:  Show 0,0,x
End SetInt

BitMapOutput 0
Locate 10,10
Print "As soon as their guard is down"
MouseWait

[BippyM]

I am using aga and the display libs. Ill figure it out next week. I move house Monday!!

[Toni Wilen]

Did you take over the system? ROM vblank routine, especially if KS3.1, will set LOF bit if it isn't already set and current system screen is not interlaced.

[BippyM]

I use "blitz" mode which apparently takes over the system for you. My asm knowledge isn't enough to do this project in pure asm so am using blitz to kind of allow me to mess about and have instant results.

I feel it's one of those things they never assumed we would need!

[clenched]

At least Toni's crystal ball still works. With the A3000 quickstart, the sample works with 2.04 ROM and flounders with 3.1 ROM . A compiled sample is in the Zone. It shows what bippym is talking about.

EDIT: Actually bippym's example works with A1200 & this ROM so the margin is even closer than before.
KS ROM v3.0 (A1200) rev 39.106 (512k) [391523-01/391524-01]

[mateusz_s]

I think it should look like this:

WBStartup

#BPLCON0 = $100
#BPLMOD1 = $108
#BPLMOD2 = $10A

#BPLCON0_MASK = %1000000000010100 ; binary
#MODULO = 80 ; line modulo for hires laced 256

; init bitmap space
BitMap 0,640,512,8

; loading 640x512 x 256 colors image
LoadBitMap 0,"dh1:test-hires-256.iff",0

BLITZ

; configure two copper lists
; custom set to -3, because 3 instructions $100+$108+$10A

cop$ = Mki$(#BPLCON0) + Mki$(#BPLCON0_MASK)
cop$ + Mki$(#BPLMOD1) + Mki$(#MODULO)
cop$ + Mki$(#BPLMOD2) + Mki$(#MODULO)

; copper nr 0 for displaying only odd lines

InitCopList 0, 44, DispHeight, $10000 + $1000 + $100 + $8, 8, 256, -3
DisplayUser 0, 0, cop$
DisplayBitMap 0,0,0,0
DisplayPalette 0,0

; copper nr 1 for displaying only even lines

InitCopList 1, 44, DispHeight, $10000 + $1000 + $100 + $8, 8, 256, -3
DisplayUser 1, 0, cop$
DisplayBitMap 1,0,0,1
DisplayPalette 1,0

; using interupt 5 to display and toggle two copper lists

counter.w = 0

SetInt 5

counter = 1 - counter

If counter = 0
CreateDisplay 0
Else
CreateDisplay 1
EndIf

End SetInt

MouseWait

End


The one thing that need to be checked is the SetInt routine. In above case the image flickers like normal interlace but in WinUAE (I can't check right now on real Amiga),
But if we use Earoks routine the image is not shaking anymore but the code throws Overflow at the end of program:

SetInt 5
counter = 1 - counter
VP = Peek.w($DFF004)

If counter = 0
CreateDisplay 0
VP BitSet 15
Else
CreateDisplay 1
VP BitClr 15
EndIf

Poke.w $DFF02A, VP

End SetInt