My NES experiment of October 2004 is the bizarro of PC 3D Accelerators! Rather than giving 3D acceleration, the NES PC2C02 Video Card gives a PC NES video acceleration using the original 2C02 Picture Processing Unit (PPU) found in Nintendo Entertainment Systems. It operates just as in the NES, but is controlled by x86 code instead of the original NES 6502.

Imagine an NES game running natively on a Pentium CPU! Imagine the complex game play, collision detection, virtually unlimited program code and RAM, and everything else fast PCs can produce, fueling an NES game! The NES PC2C02 Video Card makes it possible! It gives the ability to create the most unbelievable NES games you could ever imagine.

Just a fun experiment with no real point, but fun none the less.

Check it out: http://bripro.com/low/hardware/nesvidcard/index.php

This DOES sound pretty interesting to try out. However, I'd enjoy a few touch-ups on the 2C02, myself. For example, more than 8 sprites a scanline (how about 16? :P), and either a larger definable palette (instead of just 8 sets of 4, how about 16? :D), and possibly a larger palette, but a hue-wheel-based palette would be fine.

Hehe, if we could use the PCEngine's sound channels, this'd make a pretty neat somewhat-retro-ish system. We just need a cool controller that isn't a piece of garbage plastic like a lot of pc gamepads are. :D

- Drag

For that, you might want to just mount a Super NES PPU on an ISA card.

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As well, you can put two PPUs together, one master, one slave to get more than 16 per scanline, and dual background layers!

As the NES PPU seems to be the most difficult part of the system for emulators to get correct, couldn't an emulator use the chip to achieve perfect accuracy while emulating everything else? (CPU, internal and expansion sound, mappers and disk system, D-pads and other input devices.) At least it would be a stop gap measure until the day when cycle accurate PPU emulation is commonplace in emulators.

Why not just mount the nes to the pc, and then instead of cartridges, the emulator just "emulates" the prg rom, chr rom, mapper, and puts it to the nes's cart bus?

Hehehehehe... :D

- Drag

If you're thinking about implementing an EEPROM emulator in software, I'll warn you that the response time for that is well beyond what a typical operating system can guarantee. You'll need to cache the ROM contents on some chip, but by then, you're describing an NES flash card, right? If so, it's time for you to come on over to the new board.
http://nesdev.parodius.com/bbs/viewforum.php?f=9

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ISA? Does anyone even make motherboards that have ISA slots any more? :P

-- jdc

That's pretty cool, heheh, if it wasn't for the sound emulation I bet an emulator using that could run on a ridiculously slow PC.

As far running an NES natively on a pentium, I'd personally prefer something like a 20mhz 65C02 with lots of bankswitched RAM. :)

"I'd personally prefer something like a 20mhz 65C02 with lots of bankswitched RAM."
What you want are a Super NES and an SA-1 chip.

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SNES is fun, but it's far from 20Mhz. 65Cxxx CPUs rated for 20mhz are available currently, I believe. The plasma part in the intro of my NSF player uses almost all of the CPU's time, that's why it doesn't fill the whole screen. :)

Even doing lots of lookup table reads costs major CPU time when you get into the heavy frame-based stuff.

I'm not familair with the SA-1 (other than it was in SMRPG and a Parodius game), what's it like an add-on 65xx CPU or something? Any docs about it?

That'd be cool if it was, that'd be kinda like what I'm going for with the Squeedo cart. A high-speed coprocessor. I actually looked around for a 6502-like microcontroller, but unfortunately the only one with a 6502 core I could find was available in ROM format only, no flash or even eprom.

Sorry if it's going off-topic, heheh, but it's still a topic of enhancing old systems in ways not previously intended. :)

This page claims that the SA-1 "is also a second trimmed-down version of the SNES main CPU," in other words, a faster 65C816.
http://home.uchicago.edu/~thomas/xbox-history-nintendo-snes.html


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My English is better than your Geberquen.

The SA-1 has a 10.74MHz 65C816.