TG16's Famicom emulation, how was it done?

[Zoe F]

I didn't know if this was the right forum for this, if not, please feel free to move it.

I've seen roms of multiple Famicom games that are for the TurboGrafx. How was this done? I could be missing something really obvious, but I don't see how this would be possible. If you provide an explanation, feel free to be as technical as you want, I'll probably be able to decipher it.

*if this has been asked before, I apologize. I did use the search feature, though it's possible I merely entered the wrong search terms.

[retroman]

which roms?

[Zoe F]

There is one called 6 in 1 Famicom Collection, there is also a 5 in 1 variant. It's published and produced by a company called "Image".

[Ed Oscuro]

The NES uses a modified MOS 6502, and the PC-Engine a HuC6280 which is similar, so it's possible that a hacker could change around the bare minimum to make a FC game work on the PC-Engine. However, I'm sure NEC themselves wouldn't have made any provisions with putting Famicom games on the system as Nintendo would've put up a howl (besides the comical image of an adaptor that was tiny on one side and huge on the other, with a Famicom cart hanging off it...that's an absurd image for sure).

[Graham Mitchell]

I've played said rom; I think one of the games on it was Ice Climber, right? I remember it was pretty imperfect, with the sound being a huge issue, but it did run.

[stuffedmonkey]

I've seen screen captures of those 4 in 1 pirate HuCards - one has Super Mario Brothers..... They are sorta like the 52 in 1 pirate NES carts.

[Lost Monkey]

I am fairly certain they are not emulated, but are reprogrammed games. They are also unlicensed.

[Ed Oscuro]

Well, the word "emulation" has its problems, too. As the processor used in the PC-Engine is really just a modified 6502, it probably shares more than a handful of opcodes with the Famicom; the trick would be changing memory addresses and a few other things so the Famicom games don't look for addresses in memory that don't contain what the games think they should have. But anyhow, since the opcodes would be the same, it wouldn't really be emulation at all, rather just a minimal port.

[Zoe F]

Wouldn't porting these games require the original source code? Unless I've misunderstood the word port, which I suppose is possible.

So if I'm understanding this properly, we've basically come to the conclusion that the games were hacked by pirates to run on a nearly compatible processor? This would be the same way the handful of hacked NES games for the SNES work?

[Ed Oscuro]

So if I'm understanding this properly, we've basically come to the conclusion that the games were hacked by pirates to run on a nearly compatible processor? This would be the same way the handful of hacked NES games for the SNES work?

Yeah. They'd have to change around some memory addresses, and it might still not work, but that's the general idea I want.

[Raccoon Lad]

Semi-related note:

Yuji Naka made a Famicom Emulator for the Megadrive. He never released it, it was just something he was toying around with.

[Ed Oscuro]

Nice, heh heh. No graphics, right? Sounds sweet though.

[rbudrick]

Semi-related note:

Yuji Naka made a Famicom Emulator for the Megadrive. He never released it, it was just something he was toying around with.

Nice, heh heh. No graphics, right? Sounds sweet though.

Seriously, I'd love to see how far along he possibly could have been...it had to have ben soooo slow, even if combined withthe power of the Sega CD.

-Rob

[Zoe F]

If you want to talk slow, a company called FarSight Technologies had a project to try emulating a mode 7 SNES game on the Genesis. Who came up with that idea?

[rbudrick]

Interestingly some later Genesis titles did manage to do mode 7 stuff...not sure how. Musta been some tricky programming.

[soniko_karuto]

have u ev er played hard corps? it has a lot of scaling/rotating in it

[Zoe F]

I know a Mode 7-ish effect was definitely possible on the Genesis, but they weren't trying to do that. They were trying to actually be able to emulate a SNES game.

[rbudrick]

I know a Mode 7-ish effect was definitely possible on the Genesis, but they weren't trying to do that. They were trying to actually be able to emulate a SNES game.

Yeah, I knew what you meant, sorry. I wonder why they'd do that, though!!! Their proicessor speeds just weren't that far apart...

-Rob

[klausien]

The biggest problem isn't processor speed (the Genesis is much faster), it's color palette. Genesis can only display 64 colors onscreen at once. Also, there is a major difference between their sound hardware. I don't understand why someone would waste their time with this.

[anagrama]

In an interview with 'Edge' a couple of years back, Yuji Naka was asked about the MD Famicom emulator, and he said that it only ran SMB and was pretty buggy.