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View Full Version : Amiga A1200 with 32-bit graphics???


Gwion
01-30-2007, 02:30 PM
Can a A1200 sumhow go on 32-bit graphics?? Without a graphics card just a standard desktop A1200? :-?

SamuraiCrow
01-30-2007, 02:36 PM
Ham8 mode uses compression to render a 24-bit image as 8-bitplanes. Is that what you're referring to?

-edit- You can do software alpha-blending in a fast-memory buffer using a custom routine, and then do a chunky-to-Ham8 conversion with Kickstart 3.1 but that's terribly slow.

Flashlab
01-30-2007, 02:36 PM
I don't think so. HAM 8 on AGA is not 32 bit I thought.

Gwion
01-30-2007, 02:40 PM
What is 32-bit ram then??

SamuraiCrow
01-30-2007, 02:44 PM
The memory is accessed 32-bits at a time but the display modes are 8-bit. It just loads 32 pixels at a time using bit-planes. (Actually, it has a special fetch rate that is called "page mode" that lets it fetch two 32-bit words with a single cycle. That yields a psuedo-64-bit mode.) It's a pity that it only fetches at 14-MHz.

Gwion
01-30-2007, 02:49 PM
So its like the ide device is 16-bit

SamuraiCrow
01-30-2007, 04:35 PM
There are only 8 bitplanes whether you have 16-bit or 32-bit bus. The bus width only affects the speed of the chip because of how much data it fetches at a time.