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Old 08 December 2010, 16:58   #70
Soldering Ironman
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Join Date: Sep 2008
Location: Germany, NRW
Posts: 79
Originally Posted by NovaCoder View Post
I'd be interested in using the Indivision AGA Mrk 2 mode when it comes out.
Sadly, the Indivision AGA MK2 won't have such a mode, because the FPGA won't have direct access to the chip bus. There are just too many pins involved. On Indivision ECS, we actually saved pins by implementing the whole Denise in the FPGA.

Besides, another problem is that the CPU can only write to AGA registers using a 16 bit bus, limiting performance to 3.58 MB/s, while 32 Bit CPU Chip-Ram access is 7.14 MB/s. What can, and will be, implemented in Indivision AGA MK2 is Graffitti support. On ECS, Graffitti is of limited use, because you have to set up a hires, 4 bitplane screen, which eats almost all DMA bandwidth. Hence the new Indivision GFX mode, which always allows access to the framebuffer at maximum bus speed, no matter what resolution and colour depth.

On AGA however, hires 4 bitplanes is less DMA time consuming than lores 8 bitplanes. Meaning that 256 colour Graffitti mode is faster than 256 colour AGA mode, even if you manage to do C2P in copy time.

Originally Posted by britelite View Post
I'd be interested in adding support for Indivision ECS chunky mode to my demosystem, for those lucky ones with a 060 and Indy ECS =)
Well, when the new ADoom is finished, I'm going to release the sourcecode along with the Indivision ECS register description. The most important routines for initializing the new mode can be found in the "indivision.h" file.

Last edited by TCD; 08 December 2010 at 16:59. Reason: Back to back posts merged. Use multi-quote.
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