Search found 203 matches

by Snake
Sat May 24, 2014 7:32 am
Forum: Mega/SegaCD
Topic: Reading subcode data on the MegaCD
Replies: 12
Views: 3969

Nemesis wants to do this to rip Mega Laserdiscs - what burners can and cannot burn do not matter here. Well, it's also easy to generate the data that's actually readable (i.e. the L2 error correction stuff, and the PQ (i think?) subcodes) in software. The rest doesn't matter because it can't be rea...
by Snake
Wed May 21, 2014 5:30 am
Forum: Mega/SegaCD
Topic: Reading subcode data on the MegaCD
Replies: 12
Views: 3969

Thinking about this a little more... Maybe you need to use the ROMREAD stuff to get the audio. (*edit* or just play it as audio and call CDCREADP as TascoDLX said above...) At a hardware level, there is only one way to read the disc - the PLAY command. Maybe the only difference in the BIOS calls is ...
by Snake
Wed May 21, 2014 5:11 am
Forum: Mega/SegaCD
Topic: Reading subcode data on the MegaCD
Replies: 12
Views: 3969

I've been out of the loop forever and this is all from memory but hopefully it's useful... Do any games actually use these functions? No. these functions only return 32 bytes between them It's because of the odd way this stuff is interleaved. So, to get it all, you'd have to call either one when dat...
by Snake
Thu Apr 08, 2010 10:34 am
Forum: Video Display Processor
Topic: How does Sonic2 handle sprites for interlace mode?
Replies: 7
Views: 2805

Correct. Well, sort of. In interlace mode the system is still only displaying 224 lines per frame, it's just that one frame is all the odd lines, and the next all the even lines. So, you still only need 224 entries in the scroll table. You could change the scroll table every frame, and have all 448 ...
by Snake
Mon Jan 25, 2010 3:31 am
Forum: Megadrive/Genesis
Topic: What kind of IA can use a 16bit game?
Replies: 9
Views: 3599

Well, the Genesis should be able to handle a LOT more than this. You must be doing something pretty complicated to have issues with only 40 helicopters. Can you elaborate? I don't think it's true that all games use precalculated paths. Some do, for sure, and some use a mixture. But generally a lot o...
by Snake
Mon Jan 18, 2010 5:21 am
Forum: Video Display Processor
Topic: Megadrive video timings
Replies: 120
Views: 35046

This is straight from the Nomad screen? It may not have enough colour resolution. Do those things have a TV Out?
by Snake
Mon Jan 18, 2010 1:19 am
Forum: Blabla
Topic: some spare parts laying around.. so I built a flash cart
Replies: 11
Views: 3365

What was the cart before you 'converted' it?
by Snake
Sun Jan 17, 2010 6:16 pm
Forum: Video Display Processor
Topic: Megadrive video timings
Replies: 120
Views: 35046

Not a big deal, but it's nice to know. Oh, sure, very nice :) But a bit different to what people have been implying to me for a long time, i.e. that the whole thing was way off. It would be nice to know if steps by 36 are pretty damn close, so I can keep using those :D From what I can tell the step...
by Snake
Sat Jan 16, 2010 11:42 pm
Forum: Super 32X
Topic: DMA to PWM
Replies: 43
Views: 13870

mic_ wrote:Is there a version of Kega where this works ok? It's all distorted in 3.51, which makes it impossible to dev because you never know if there distortions come from a bug in your program or from the emulator.
It works perfectly in Mono, only Stereo is distorted. I'll fix it up when I get a chance.
by Snake
Fri Jan 15, 2010 1:14 am
Forum: Super 32X
Topic: DMA to PWM
Replies: 43
Views: 13870

One thing I was wondering - is it really necessary to bang on the FRT like in all the SEGA examples? No. That's probably down to the workaround they provided for a hardware bug. Basically when you hit the reset button not everything gets reset, and this can cause the whole system to lock up. The wo...
by Snake
Thu Jan 14, 2010 5:47 am
Forum: Super 32X
Topic: DMA to PWM
Replies: 43
Views: 13870

Chilly Willy wrote:Yeah - looking at the diagnostic cart
....and I don't even know where that came from - it certainly was not supplied with any of my many dev kits. I'm not even sure it was supposed to leave Sega.
by Snake
Thu Jan 14, 2010 12:51 am
Forum: Hardware
Topic: MD2 + YM2413 = Total Awesomness :D
Replies: 14
Views: 7900

This is SERIOUSLY awesome. I want one.
by Snake
Thu Jan 14, 2010 12:47 am
Forum: Super 32X
Topic: DMA to PWM
Replies: 43
Views: 13870

Graz wrote:I started with the leaked official docs, and it seemed pretty much obvious to me. I thought it was the recommended way to do things.
Well, I can tell you that the docs available at the time didn't make it at all clear :(
by Snake
Thu Jan 14, 2010 12:44 am
Forum: Video Display Processor
Topic: Megadrive video timings
Replies: 120
Views: 35046

It was all posted on a devchannel set up by (I believe) Charles Macdonald, and I don't know if it's still around. I did keep notes of a lot of this stuff but then lost it :evil: However, pretty much every emulator out there since then handles all the stuff I found.
by Snake
Thu Jan 14, 2010 12:26 am
Forum: Super 32X
Topic: DMA to PWM
Replies: 43
Views: 13870

It's really annoying. Given that none of the RAM in the 32X is really fast enough, DMA is a complete waste of time - except for this purpose, where its - well - awesome. The perfect solution, and as you say, the PWM quality is outstanding. But instead we get low quality audio because nobody wanted t...