a few 3DO questions

[Secessionist]

What's the response time on the controller port? Isn't it the same as the Genesis and SMS?

Why does it output at higher resolution (640x480) than it renders at (320x240 internally)?

Can it do true trilinear texture filtering or is the "trilinear interpolation" mentioned in specifications something totally unrelated?

Sorry for the noobish questions.

 

[swaaye]

I've noticed that it looks like it does some sort of processing when it outputs the image. At least I think it's the 3DO doing it and not my TV.

It's hard to find much info on the "Cel engine" inside the 3DO. It's not really all that impressive though. A notch above SuperFX chip / 32X maybe but not much.

 

[Grall]

It's not very powerful with today's standards of course, but it's certainly a lot beefier than the stupid superfx. For starters it does proper high-color rendering, good alpha blending, more complex 3D models and so on at significantly higher framerates than the fx manages very rudimentary 3D imagery both in bit depth and color depth.

3DO claimed the machine did 640*480, but that's a lie of course, it's just good ol 3xx*2xx interpolated/averaged vertically and horizontally. Purely a bulletpoint feature that hardly affects image quality at all. This is probably also the source of the 'trilinear interpolation' mentioned in the OP; I don't think the 3DO did texture filtering at all. I believe it only handled point sampling when texturing. So anything 'trilinear' related to the 3DO is most likely another non-existant theoretical feature...

Oh, and the joypads were custom, since they could be daisychained. The unit only had one controller port. I can't remember what the connector looked like though, if it was a 9-pin DSUB or something else...

 

[Silanda]

Oh, and the joypads were custom, since they could be daisychained. The unit only had one controller port. I can't remember what the connector looked like though, if it was a 9-pin DSUB or something else...

It was a 9-pin D-Sub. An odd choice really as it was completely incompatible with other game controllers using that connector and, allegedly, attempting to use them could damage the 3DO.

 

[swaaye]

Yup it is the same as a 9pin serial port connector, except for the pinout of course.

I finally bought myself a 3DO recently. I've been wanting to have one for a long time. The library is primarily bad FMV games, pre-rendered Rebel Assault clones, and Wolf3D-style maze shooters. I like a few of the games though. It's an interesting look at a time when CDROMs were used all wrong.

There are some realtime 3D games with PS1/Saturn style ultra-blocky warping 3D graphics, but really slow framerates ranging from 5-15 fps I'd say. Obviously there's no texture "filtering". Some games have serious perspective correction issues. Barely playable. The best looking games use streaming video to fake realtime 3D. A few of the realtime 3D games are ok though, like NFS and Road Rash.

I'd say the hardware is similar to a 386 PC with a really gimpy 3D board. Playing Super Wing Commander and watching it chop out like crazy made me think that. Also, the inability for it to run even a rewritten Doom engine satisfactorily. Apparently the game developers had to program their games with a 3DO API because the hardware could vary between manufacturers. I thought that was interesting.

I stumbled on a Popular Science article on Google that covers the hardware somewhat in depth. The goofy marketing terminology of the day was calling the display hardware a "cel animation engine".
http://books.google.com/books?id=_YuuteSpekkC&lpg=PA104&ots=I_r_ZQR-gi&dq=3do%20cpu%20popular%20science&pg=PA101#v=onepage&q=&f=false

 

[ERP]

Why does it output at higher resolution (640x480) than it renders at (320x240 internally)?

I never worked on the original 3DO but I believe the reason is that it interpolated brightness values between rendered pixels on output.

 

[Secessionist]

Okay thanks guys. I appreciate it. Does anyone know the response time of 9-pin serial ports or does that vary from system to system?

 

[swaaye]

I'm pretty sure they just use the connector and that those are not actual serial ports.
http://groups.google.com/group/rec....f563a70d0e95f33?lnk=st&q=3do+controller&pli=1

...it has a complex bidirectional serial signalling protocol. There's a custom chip in the controller which implements this protocol, and as far as I know there isn't any other vendor's joystick or control pad which uses a similar protocol.

See, the 3DO control port works in a way similar to the ADB port for the Mac, i.e., a digital control port, ...

 

[Karamazov]

hard to believe that this game was from Naughty dog
http://www.youtube.com/watch?v=CUNeKmHvVWM

I remember being amazed by need for speed for 3do at the time

http://www.youtube.com/watch?v=B1DgUpt5fbs

 

[Silanda]

I'd say the hardware is similar to a 386 PC with a really gimpy 3D board. Playing Super Wing Commander and watching it chop out like crazy made me think that. Also, the inability for it to run even a rewritten Doom engine satisfactorily. Apparently the game developers had to program their games with a 3DO API because the hardware could vary between manufacturers. I thought that was interesting.

The Doom port was a rush job done in ten weeks or less, so it's not the best example to determine the power of the system on. As for Super Wing Commander, well Wing Commander III says hello. It was pretty smooth, more colourful than the PC version, and had better video quality than the PC version. It could not be done on a 386.

 

[TheWretched]

Well, the PC version was a bit castrated, since they only wanted to use the "smallish" 64 minute CDs, as not every CDROM actually did support full cds, back in the day.

 

[swaaye]

The Doom port was a rush job done in ten weeks or less, so it's not the best example to determine the power of the system on.

That's not what I've read. They gave up trying to port the Doom engine, so wrote their own. Their programmers gave up and quit, brought in new guys. Etc. After playing the other 3DO shooters, I can imagine that Doom was just a bit out of its reach. Even Carmack himself working on the somewhat superior Jaguar couldn't pull it off very well.
http://cdinteractive.co.uk/3do/forum/viewtopic.php?t=1101&start=0 (lots of info)

Gotta love that pre-release bullshitting with regards to it actually being superior! lmao

As for Super Wing Commander, well Wing Commander III says hello. It was pretty smooth, more colourful than the PC version, and had better video quality than the PC version. It could not be done on a 386.

I haven't messed with Wing 3 yet because I'm convinced that the PC version is superior considering it can do 640x480 (and smoothly of course on almost anything faster than a 486). That's most important to me.

Even though flawed, Super WC is a fascinating update to the original game and it's why I recently bought a 3DO. I've been wanting to try it out for years.

 

[Silanda]

That's not what I've read. They gave up trying to port the Doom engine, so wrote their own. Their programmers gave up and quit, brought in new guys.

Hmm, whether Art Data's version of events are close to reality, or whether they were simply incompetent and lying throught their teeth is unknown. However, the information regarding the length of time it was coded in is fact. This is a usenet post from back in the day in which the programmer, Bill Heineman, mentions the development: http://groups.google.com/group/rec....read/thread/818673bc6dac714a/fa88da3bee0e66de

 

[swaaye]

It sounds like they were in over their heads and had to farm it out to make it happen. On PC, Doom runs entirely on the CPU (ideally 486-level). The 3DO CPU is definitely no 486-33. Doom doesn't use an FPU AFAIK so 3DO's extra hardware there is of no use. It also doesn't use any form of graphics co-processors (the vid card is just a dumb framebuffer). So you're not going to just be able to recompile Doom source and run it on 3DO, and then there's also the issue of Doom needing 4MB RAM, 33% more than 3DO has.

I don't know when the first competent Doom port happened. Did PS1 pull it off? Doom64 is awesome but isn't the same game and has some significant enhancements.

 

[Silanda]

I don't know when the first competent Doom port happened. Did PS1 pull it off? Doom64 is awesome but isn't the same game and has some significant enhancements.

Hmm tricky, I'd say the Jaguar version although it's missing the music and had slightly simplified levels. To be fair though, all of the 90's ports used the Jaguars simplified levels (assumedly to save memory). The Playstation version was pretty good from what I remember though.

 

[swaaye]

Reminds me of years ago when my bro and I beat Doom GBA in coop mode via link cable. It runs pretty well on there. That's based on the Jag version as well.

 

[Colonel]

What about the super nes version? I know the super fx chip was in it, so does that say the super fx was more powerful than than 3do's twin cell engines? I find the super fx powered doom more intersrecting in that doom needed 4MB to run and am sure the snes and super fx didnt come close to 4MB. I will go check to be sure.

Went and checked so nevermind

 

[swaaye]

 

[Grall]

The SNES version had terrible framerates - as expected perhaps - and all the enemies were greatly reduced in resolution as well (and had only four viewing angles as to the original eight of the PC version).

As I seem to recall, the levels were missing some of the decorative doodads and textures also, but I can't quite remember if the geometry itself was simplified, and how much. I guess it was... Still, that the SNES could run it at all was a pretty major accomplishment. I'm not quite sure exactly what hardware was on the cart, I heard the SuperFX was basically just a faster-clocked SNES CPU-compatible processor - 12MHz for the original SuperFX Starfox, and 21MHz-ish for the FX 2 used in Doom and a bunch of other games. Not sure how much DRAM was on those carts, 256-512k? I assume it had to store everything, all the textures, program code and framebuffer. Or maybe the SNES RAM could be used as framebuffer if cartridge port access was fast enough, CPU access to SNES framebuffer was iiiincreeeedddibly slow from what I understand (except Jurassic Park somehow ran a textured 3D engine on the CPU itself at somewhat playable speed!).

 

[Karamazov]

always wondered if the atari lynx would have been able to handle a doom port.