AGA Palette... how to implement

[Steve]

Cheers guys. It works now - albeit with a bit of a noise at bottom.

Cheers for all your help, been a fun evening.

[ross]

Originally Posted by Steve

Cheers guys. It works now - albeit with a bit of a noise at bottom.

Sure you inserted DIWSTOP,$F4C1 in copper list?
This is the effect of a wrong DIWSTOP.

EDIT.
To explain the reason: I see that you setup DIWSTOP in code and in copper list.
DIWSTOP is a static value so you can use CPU or copper, but with copper the value is refreshed every frame so the first CPU setup can be overwritten.

[Steve]

Originally Posted by ross

Sure you inserted DIWSTOP,$F4C1 in copper list?
This is the effect of a wrong DIWSTOP.

Ha, you're right again Ross!

I had removed it while switching between images. Added it back in and it looks correct.

Much appreciated!

Onwards to the next challenge. Maybe I'll look at the blitter next.

Thanks again.

Originally Posted by ross

To explain the reason: I see that you setup DIWSTOP in code and in copper list.
DIWSTOP is a static value so you can use CPU or copper, but with copper the value is refreshed every frame so the first CPU setup can be overwritten.

Thanks Ross, that's good to know. So really it only needs setting once. I'm learning plenty this evening!

[Steve]

Okay so here is my first little 'demo' (if you can call it that) which I am a bit chuffed with right now. Even if it doesn't do a lot, it's the first decent thing I have created with assembler.

It is a bootable ADF file that tests the machine it is running on. If it detects the AGA chipset then it loads the Tutankhamun image (256 colours) otherwise it loads a 32 colour image of a disk (done by Foul). Yeah pretty chuffed with that bit of work.

Running one program on different machines/chipsets with different results fascinates me for some reason.

EDIT: I made a small update to the code which now loads the 320x200 version with the correct aspect ratio (the 320x256 version was stretched vertically and didn't look like the real King Tut mask). I also fixed a problem with the floppy drive motor light staying on.