Looking for SNES documentation

Looking for SNES documentation
by jwdonal on 2011-05-23 (#78600)

Hey all,

I'm interested in learning how the SNES hardware works. I was hoping you guys could point me in the right direction for the best documentation. I'm looking for documentation similar to Brad Taylor's CPU/PPU tech docs for the NES (i.e. similar in purpose, not in accuracy......just sayin

).

Also, what are the best IRC channels to ask questions about SNES emulator development?

Also, where can I download some good initial test ROMs (CPU-only, basic graphics tests, etc)?

Also, what would be the easiest official SNES game to try and get working first (i.e. what game uses the least or most basic features of the SNES)? For example, when I first started working on my NES emu the first game I got working was the original Mario Bros. because it had no scrolling of any kind.

Also, what are people's opinions on the difficulty level of writing an SNES emu compared to NES emu? Slightly harder? A lot harder? I can probably figure this question out myself once I get the right documentation in hand.

Thanks!

Jonathon

by mic_ on 2011-05-23 (#78603)

Quote:
I was hoping you guys could point me in the right direction for the best documentation. I'm looking for documentation similar to Brad Taylor's CPU/PPU tech docs for the NES

http://www.westerndesigncenter.com/wdc/datasheets/Programmanual.pdf (65C816)
http://www.romhacking.net/docs/193/
http://www.romhacking.net/docs/196/
http://www.romhacking.net/docs/197/
http://ekid.nintendev.com/snes/spctech.htm

Quote:
Also, what are people's opinions on the difficulty level of writing an SNES emu compared to NES emu? Slightly harder? A lot harder?

Not sure about "harder". But I'd say a lot more work.

Re: Looking for SNES documentation
by byuu on 2011-05-23 (#78608)

Quote:
I'm looking for documentation similar to Brad Taylor's CPU/PPU tech docs for the NES (i.e. similar in purpose, not in accuracy......just sayin ;)).

If you mean the PPU cycle timings, they don't exist. Otherwise, find anomie's docs.

Quote:
Also, what are the best IRC channels to ask questions about SNES emulator development?

#2001. Sorry, nobody I know is actively researching SNES hardware at this time.

Quote:
Also, what would be the easiest official SNES game to try and get working first

First game I had playable was Super Valis IV. Intro Mode7 came later, of course. But in-game was pretty easy. If you hate scrolling, you should really consider the 'PD' Pacman homebrew game. It's quite good.

Quote:
Also, what are people's opinions on the difficulty level of writing an SNES emu compared to NES emu?

I think Disch is the only one fully qualified to answer that question. But if you go off number of NES emus to number of SNES emus, then it is 2,714 times harder ;)

by jwdonal on 2011-05-25 (#78667)

Thanks a lot for your help guys! Much appreciated.

Re: Looking for SNES documentation
by MottZilla on 2011-05-25 (#78668)

byuu wrote:
Quote:
Also, what are people's opinions on the difficulty level of writing an SNES emu compared to NES emu?

I think Disch is the only one fully qualified to answer that question. But if you go off number of NES emus to number of SNES emus, then it is 2,714 times harder

That sounds about right! There is alot more to the SNES than there is to the NES. SNES will take you alot more time depending on your goals. Just consider how long projects like SNES9X, ZSNES, BSNES, etc have been in development. I'd say it's alot easier to make a NES emulator that is fairly complete and accurate than it is to do so for the SNES. The Genesis and Gameboy are probably easier.

I was thinking about trying to write my own SNES emulator but haven't gotten around to trying due to the massive scale of the task in relation to NES and Gameboy. Plus it seems like there are less emulation targeted documents for SNES than there were for both NES and GB. But it's probably a fun project.

Re: Looking for SNES documentation
by byuu on 2011-05-25 (#78714)

MottZilla wrote:
The Genesis and Gameboy are probably easier.

I dunno about the Genesis (the 68k in particular looks annoying as all hell), but the Gameboy is a breeze. I made it to ~95% compatibility in a week. Problem there is most are closed source, and asking for any help on poorly documented areas (eg almost anything) just gets you flat out misleading and bad info. I don't suspect it's malicious, but yeah, total waste of time to ask any questions in #gbdev. They are very nice and friendly people though.

Quote:
But it's probably a fun project.

It's a ton of fun up to 98% or so compatibility. But all the troublesome games with crazy timing issues are titles like Jumbo Osaki no Hole in One Golf, Mecarobot Golf, Speedy Gonzales, Toy Story, WWF Wrestling, Air Strike Patrol, Power Rangers: Fighting Edition, Sink or Swim, etc. Eg the stuff developers rushed out the door.

You'll never get to debug any issues in great games like Zelda, Metroid, Contra, Castlevania, Secret of Mana, Final Fantasy, Chrono Trigger, etc. Even Battletoads only had one minor issue (you need to clamp the PITCH register to 14-bits or the sound is distorted.)

The PPU will cause your hair to gray though, I must admit. Soooooooooooo many register settings that all interact together in impossibly complex ways.

by MottZilla on 2011-05-25 (#78718)

What was tricky about Power Rangers Fighting Edition?