Neo Geo CD Universe Bios 3.2 Released!

Probably a noob question but how are you running games without a CD drive?

wyo_vr4 said:

Probably a noob question but how are you running games without a CD drive?

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That's what PC2NEO USB does. It's main purpose is running homebrew code but it can also run CD games or small MVS games loaded directly into NGCD Ram. It loads code faster than the CD reader which I'm sure isn't that hard to believe

In the photo I posted I removed the CD drive as it was faulty and I had no plans on fixing it. This may not be ideal for those who want to use PC2NEO for playing CD games vs development since CD games have their soundtracks stored as Redbook audio tracks. Sound effects still play but the CD audio wont for obvious reasons. If the CD were installed the game code would load over usb and the audio would stream from the game disc. Further, some CD games don't use CD audio , like Puzzle Bobble for instance. That game loaded over USB with no CD drive has full soundtrack and sound effects. MVS games have no concept of CD audio so if they are loaded they will play both soundtrack and sound effects assuming they can fit in NGCD ram.

mike, yes I know that and that socket adapter part might even fit. But if I handmake board, I would use slim one row connectors in both side of the eprom to get it fit like its in my picture.

But hey, sell me a pc-2-neo usb

Attached using super strong double side tape.

miisalo said:

mike, yes I know that and that socket adapter part might even fit. But if I handmake board, I would use slim one row connectors in both side of the eprom to get it fit like its in my picture.

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That's a very good idea. One thing that might help with wire routing is to use 2.0mm IDC cabling. It's a bummer that the 68K is on the rear of the board and my brain started to hurt when looking for a way to mount the Neobiosmasta and keep the stock case. I decided for my purposes the case would get in the way and that actually worked out very well.

Universe Bios for NGCD was successfully tested on the Top Loader, Front Loader, and CDZ. Neoturfmasta was instrumental in testing the core Universe Bios functionality on these platforms. What wasn't thoroughly tested was the PC2NEO functionality on anything other than the Top Loader. The reason for this was simply because I didn't have a CDZ until recently.

As soon as I modded my CDZ I ran some tests and discovered that hardware differences between the TL and CDZ were causing transfer problems on the stock bios. I immediately shared this info with Raz and he immediately made a CDZ fix. It turns out the transfer performance of the CDZ is actually better than the TL and I'm attributing that to the design of the CDZ joystick front-end. The CDZ does not use the NEO-BUF chips and it has a discreet implementation of the resistor/cap arrays found on the TL. Those seem to add a level of debounce to the lines which translates to a delay which is not present on the CDZ.

My next project is to populate all the blank DRAM pad landings with memory chips. Neoturfmasta had done this but I don't think at the time there was a good way of testing whether this memory was accessible. If it is then it will certainly allow for much larger MVS games to be developed or played.

Thanks,
Mike

Nice, you got it all to fit

Raz

mikew said:

T I immediately shared this info with Raz and he immediately made a CDZ fix.

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I'd like to add that although there's code being tested, these CDZ fixes and other Universe Bios enhancements will be available in a future release and that could be a long ways out.

The fix allows for the high speed and compression modes to be active. Without the fix only the normal transfer mode is available. That mode is still quite fast in comparison to a 1X CD load.

Razoola said:

I guess that's possible but I don't have much free time at the moment to look into it.

Raz

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ok thanks for the answer!

Hello
For information i publish an little interview of Razoola and his work in my webpage (interview and in the end "Razoola et son Unibios Neo Geo CD (et autres projets)")
the fisrt are in french but in the end you have the interview in english

thanks again to razoola

Ohh, you forgot to add a switch so it can swap between the CDZ bios and the MVS bios that's on the chip. I think to do that you simply need to hold the high address line so the last 0x40000 bytes is first.

Yes, forgot to ask about it. So switch connecting Vcc (pin 21) to A17 (pin 1) should do the trick? I should have some switches somewhere.

Im not 100% sure to be honest but I think that's right.

miisalo said:

Yes, forgot to ask about it. So switch connecting Vcc (pin 21) to A17 (pin 1) should do the trick? I should have some switches somewhere.

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You need to lift A17 and put VCC to it to bank switch. You cannot just put VCC to A17 while A17 is still connected to the system.

Good to mention that. It should go without saying not to connect that A17 back to the board if I have Vcc on that address line. Switch connecting either GND/A17 or Vcc to eprom's A17 then, better not to have eprom's A17 floating.

Finally had time to install switch. Basically eproms A17 can be now switched between address line or Vcc.

Great stuff miisalo!

Is there a free version of the NGCD UniBIOS, or a discount for people who can burn and provide their own EPROMs?

There is no free version presently and there may not be one for some time. You can contact me directly from the homepage email though about obtaining an electronic version.

Looks like you already responded to my March 6th email, guess I somehow missed it.
Sent you another one with some questions about how purchasing works.

Ohhh,I have been enlightened by this thread... Wife won't be happy!

well I just purchased it now so awaiting for it to come and get someone to install it

Thanks, Am sorting out your bios here now.

Raz

Miisalo needs to move to America so I can convince him to put a Unibios into my CDZ.

Razoola said:

Thanks, Am sorting out your bios here now.

Raz

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ok well as I said I will get an expert to put it in, also you know how to save or copy all my saves on my Neo CD?

Yes that's possible but you will require a pc2neo.

Raz