32X strengths

Ask anything your want about the 32X Mushroom programming.

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commodorejohn
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Post by commodorejohn » Sat Jul 14, 2007 8:07 pm

Yeah, but if you were going to do it on SCD anyway, it'd make sense to just use the sample playback chip instead of having to do manual writes. On the other hand, you could have the Z80 do sound effects with the 32X PWM and use the 8 SCD channels for wavetable music, getting something closer to SNES DOOM in terms of musical quality (although it's certainly possible to do the DOOM soundtrack well on YM2612, they just didn't.)

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Post by evildragon » Sat Jul 14, 2007 8:14 pm

3do Doom had the BEST music... it's supposedly RedBook format..

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Post by commodorejohn » Sat Jul 14, 2007 8:39 pm

I just looked up a YouTube clip; wow, that is good. I suppose if you were doing it on SCD you could use the Redbook capability and the 3DO soundtrack, but I'd definitely include support for synth or wavetable MIDI (after all, half the point of an SCD version would be for other DOOM engine games and expansion WADs!)

P.S. With that 32X demo tape at the start of the thread, was the ROM for that ever dumped? I'd like to see that running on an emulator (i.e. without the crappy VHS blurring.)

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Post by TascoDLX » Mon Jul 16, 2007 10:30 am

commodorejohn wrote:DOOM isn't a 100% basic raycaster like Wolfenstein, no, but raycasting is still the bulk of the rendering.
Actually it's not, but it's not worth arguing either.

32X CD seems like overkill. The most favorable method would be playing music through the YM -- assuming someone took the time to recompose it -- and sound FX through the 32X's PWM. However, storage on a cartridge is limited and using the CD for storing a whole mess of WADs is tempting.

As for that pesky DOOM engine, you can find the source code here... still on id's ftp after all these years.

Here's an idea: one SH-2 handles the BSP tree stuff (sorting and culling) and the transform, and passes data to the other SH-2 for drawing. The 68K should be able to handle the app code including collision detection. Might need some load balancing.

Interesting project idea. Wouldn't be the first DOOM port :wink:

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Post by commodorejohn » Mon Jul 16, 2007 1:44 pm

Hmm, I always thought it was. Anyway, yeah, I was suggesting 32X CD for storage reasons rather than extra processing power - while I'm impressed with what they managed to squeeze into 3MB, you really just can't pull off a decent port of a 10MB game on a system with a maximum 4MB cartridge space (heck, even Super Street Fighter II only pushed it to 6MB with bankswitching on the cart.) It should be done in 10MB if for no other reason than being able to sneak up on enemies again. I'd be happy to provide a redone soundtrack, but I wonder if it would be possible to use the game MIDIs and just provide a better YM2612 patch library (I wonder if 32X DOOM did that in the first place, or used some other format geared specifically towards the Genesis.)

You know what I'd really like though? Wolfenstein, that's what. The only decent port I've seen of that is the GBA version. I wonder, though, if you couldn't run it on plain old Sega CD rather than 32X (it's a pretty simple game, after all.)

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evildragon
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Post by evildragon » Mon Jul 16, 2007 2:21 pm

i couldn't help but notice that the 32X port of DOOM has horizontally doubled pixels, making it, in the PC version of DOOM, "Low Detail"...

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Post by commodorejohn » Mon Jul 16, 2007 2:47 pm

So it does, but given that the original runs on a 25MHz 386, I can't imagine that this is because the 32X can't handle full resolution. I mean, we already know that the port was shoddy, and I expect that the column-doubling and reduced screen size (ugh, I hate the reduced screen size) are the fault of the port.

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Post by evildragon » Mon Jul 16, 2007 2:56 pm

well, if anyone reports it on the 32X CD, let me know of an ISO download, I have official WADs from my DOS and Mac versions I could use for them..

I'd just love to enjoy a better port of DOOM.. I mean, on level one, the ground is BROWN at the walk in-area, the PC version was a sparkly blue.. I remember those colors from my old 1987 IBM VGA monitor :p

(which is used on my DreamCast now)

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Post by Mask of Destiny » Mon Jul 16, 2007 4:55 pm

commodorejohn wrote:heck, even Super Street Fighter II only pushed it to 6MB with bankswitching on the cart.
Actually, it was only 5MB, but the problem is probably one of ROM cost than ability to access more space easily.

I would think the limited RAM available in the 32X would make a 32X/CD DOOM port difficult though.
You know what I'd really like though? Wolfenstein, that's what. The only decent port I've seen of that is the GBA version. I wonder, though, if you couldn't run it on plain old Sega CD rather than 32X (it's a pretty simple game, after all.)
I'm pretty sure the original ran on a 6MHz 286 so the 12.5 MHz 68K in the Sega CD should be able to do the job especially since, at least in theory, some of the code could be offloaded to the Genesis CPU and/or Z80 leaving the Sega CD CPU free to focus on rendering.

VDP DMA bandwidth might limit your max framerate. I believe I calculated it to be around 12FPS if you're trying to update the whole screen. Of course, in Wolf 3D part of the screen is covered by the HUD so I'm not sure how much of an issue it would be.

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Post by Fonzie » Mon Jul 16, 2007 5:07 pm

If i remember correctly, you could even render the wolfenstein walls in a single Planedrawing hardware operation (just adding a 90° to the output and doing raster on Y position & Scale).

Of course, the plane would contain all the walls textures :)


It's quite sad that nobody ported wolf to md or even segacd, as mentioned by MOD, yet...

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Post by evildragon » Mon Jul 16, 2007 5:35 pm

Fonzie wrote:If i remember correctly, you could even render the wolfenstein walls in a single Planedrawing hardware operation (just adding a 90° to the output and doing raster on Y position & Scale).

Of course, the plane would contain all the walls textures :)


It's quite sad that nobody ported wolf to md or even segacd, as mentioned by MOD, yet...
isn't this how Duke 3D for MD worked?

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Post by commodorejohn » Mon Jul 16, 2007 10:49 pm

Fonzie wrote:It's quite sad that nobody ported wolf to md or even segacd, as mentioned by MOD, yet...
Yeah...on the other hand, though, looking at how the SNES Wolfenstein came out, I'm glad they didn't. Although the censorship wouldn't have been a problem like on the SNES, the port itself was pretty poor (and it sure didn't help that the cart was only 1MB...)

As far as DOOM goes, yeah, I suppose RAM limits would be a problem. I wonder how much a typical level takes? I'm sure the BSP and the textures are the bulk of it, but exactly how much? How does 32X DOOM deal with only having 256KB of RAM?

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Post by Shiru » Mon Jul 16, 2007 11:28 pm

commodorejohn wrote:Yeah...on the other hand, though, looking at how the SNES Wolfenstein came out, I'm glad they didn't. Although the censorship wouldn't have been a problem like on the SNES, the port itself was pretty poor
SNES has weak CPU.

I'm pretty sure it's possible to make decent port of Wolf3D for SMD, with good framerate etc. 3D actions which already exists on SMD (ZT, BS) has much complicate technology than Wolf3D, and they playable enough even with not so high framerate.

Besides, I think, there is no reason to make such port. I like ZT and BS, these games not available on other platforms, so it's reason for me to like SMD. But I don't need SMD to play Wolf3D right now, or many years ago, and I will not need in SMD for that in future. Maybe I run port to see how it works, but I will not play it for long time. And I think many people think this way. So, it will be better to make new original games (maybe with Wolf3D-like technology) instead of porting old ones.

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Post by commodorejohn » Mon Jul 16, 2007 11:59 pm

Oh, it's absolutely possible, I'm just saying that I'm glad they didn't, given how they did on the SNES port.

As far as ports vs. original content, I see your point, but ports are great as a programming excercise because the game's already done, and your task is just to understand enough about how the console works to make the game run on it. And besides, it's not there aren't other games that use the DOOM engine (or, for that matter, the Wolfenstein engine) that never got a port. It'd actually be pretty cool to have 32X Heretic.

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Post by TmEE co.(TM) » Tue Jul 17, 2007 8:28 am

How about Rise Of The Triad ? It looks fairly easy to do, and I love that game, especially with \EKG - BEST GIBS EVER !!! And 3Drealms/ex Apogee has made source, gfx, sfx, bgms available...
Mida sa loed ? Nagunii aru ei saa ;)
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Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen

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