Quote:
Originally Posted by Gunnar
Did I understand this right, did you do the NEO-GEO emulator?
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Correct.
Quote:
Originally Posted by Gunnar
Can you please explain a little bit how the chipset is accessed on NEO-GEO,
so that we understand what would be needed to emulate it?
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Well, alexh already posted the
link to the Atari Forum discussion and I strongly recommend to read the whole thread to understand how it works and why the emulation is (currently) not working on an MC68060.
The Neo Geo hardware is rather simple compared to a computer like the Amiga yet more powerful for sprite based games. E.g. it doesn't have/need controllers for like data storage or serial ports so there are only a few hardware registers. The sprite interface is also very "special" but it's a straight forward implementation and everything you see on the screen (except for the text layer) is comprised of sprites so the current emulation program on the Atari Falcon fits in only about 20 kilobytes.
There is a very good
development related Neo Geo website which was my only source while developing the emulator and is really helpful to understand the Neo Geo system.
Quote:
Originally Posted by Gunnar
Lets say you would have an AMIGA with the following specs.
Fast 68k CPU > 100 MIPS
128 MB fast memory
15bit direct color framebuffer
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Well, performance wise that would be ideal.
Quote:
Originally Posted by Gunnar
How much effort would you estimate to get the NEO-GEO emulator running?
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This depends only on the question if the MC68060 bus error handling is "good" enough for the current approach. Unfortunately I don't have a accelerated machine here to make some tests on. Running the Neo Geo emulator in an emulator environment doesn't work and so debugging on a real hardware with altered MMU tables is really challenging.
Quote:
Originally Posted by Gunnar
Could all NEO GEO games run this way?
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So far mostly will. However there are some games which do some nasty stack frame modifications (at least Viewpoint does it) but that issue could be patched. Self modifying code is also very rare on ROM based systems.
Cheers
Sascha