Sunday, January 17, 2010

Analyse.. don't Destroy (a Casio PV-1000)

I'm not a console collector nut, I'm a audio chip collector nut. There are countless game consoles and computers out there that I dont care much about because they all contain the same chips. (AY-3-8910 is nice, but you can only have so many of them).

What I'm looking to acquire at this point are the most obscure ones which contain custom/unique sound generating chips. You've heard about the CASIO PV-1000 before?



Don't worry, only the most die hard console collectors did. And they would die for it too. There are very very few such consoles out there and I got mine a bit by chance, and it was an impulse buy.

At 300$ (ebay), you just can't afford to ruin it can you? (I'm not a movie producer). And I look forward to its resell value once im done with it. Thats where the challenge comes in... how do I take a device that comes with just a NTSC-J RF adapter and get good enough audio results with it? (the RF channels on North american and Japan dont match... dont try)

The closest I got to getting a picture/sound from the default unit as is was to use a ANALOG/DIGITAL USB TV tuner, which had by chance a NTSC-J mode:




Not that bad, but, the audio was horrendous, and really not usable for my tests. However I've hacked nearly all my consoles in order to have separate composite video/audio from RCA jacks, so on top of some test equipement, i've got a few hunches on how to solve this cleanly.

the RF box is tied to the main motherboard in a very clean way:

A few minutes with my multimeter, from top to bottom:
1)9VDC (current for the amplifiers in the RF sections i assume)
2)GND
3)Composite Video Out.. YAY!
4)GND (same as 2)
5)Audio Out...  w00t!

Connecting Aligator jumpers to truncated ends of a RCA and to the pins 3,4 and 5 did provide me with a temporary solution, but surely isnt very practical for a longer term analysis.


Oups, where did the RF box go? (in a safe place in case I resell it and the buyer really is after lots of  pain and suffering).



Much better.
 From the outside:


Enjoy the OK quality outputs:

8 comments:

  1. Hi David,

    I'm the guy who sold you the Bally Astrocade
    a few months ago, hope that you have fun with it. But i'm asking you if you have data on the D65010G031 (video & audio chip). Is it a TMS9918 with a palette of 8 colors and a AY-3-8910 ? Because i'm trying to built an adaptor to play Casio PV-1000 games on the Colecovision. Thanks in advanced for any infos! :)

    --- Sly DC ---

    ReplyDelete
  2. Hi, and thanks for the MPT03 and the O2 as well :)
    (you are in the credits of chipsounds's manual)

    The PV-1000's D65010G031 is really a different beast than a Colecovision, so i doubt there is any chance there.

    Wilbert Pol has done the Video Emulation, while i did the audio emulation for MESS's PV-1000 driver here:

    http://git.redump.net/cgit.cgi/mess/tree/src/mess/drivers/pv1000.c

    While i dont know if there is any similarity between the TMS9918 and the D65010G031 on the video side, i can assure you that the audio side is neither a AY-3-8910 nor a SN76489, but something much more simplistic. Three registers/channels of square wavs at 6bit resolution. (compared to the 10bits of the SN and its noise channel)

    Kind Regards!

    ReplyDelete
  3. http://www.videogameconsolelibrary.com/pg80-pv1000.htm#page=ratings says we could have 32kb rom cartridges, but i'm struggling on creating 32kb rom files for Mess via Boriel’s ZX-Basic Compiler ( my "successful" attempts on targeting PV1000 are at http://www.boriel.com/wiki/en/index.php/ZX_BASIC:Released_Programs_-_PV1000 ) - i think somewhere in the mamedev code is preventing 32kb roms (and other sizes that are not 8kb or 16kb) to be loaded, because no one were commercially released, difficulting homebrew developers for using this size?

    ReplyDelete
    Replies
    1. Its true that the MESS driver currently has a fixed size limit "if (size != 0x2000 && size != 0x4000)" as there are no carts that use more. Its been a while since I looked at this, but If i trust http://www43.tok2.com/home/cmpslv/Pv1000/EnrPV1.htm there is no A14 line going to the cart, just A15 and will be 0 by the CPU (if its 1 then the graphics ram and cart rom would overlap).

      Delete
    2. Using an emulator you could make a 32k rom, but it wouldnt work on a real system unless you use a mapper, or tie a direct A14 connection between the console's Z80 and the rom in the cart (ugh)

      Delete
  4. the situation about mappers is the huge need of conventions, and the less as possible (like ascii-8k, ascii-16k, konami-megarom, etc., on the msx side), and since no classic games used that, we needed a quite "intense" homebrew game development (specially physical, like happens on ColecoVision) for making it as "convention" and use it on emulators without any problems - btw, i recall that once in a forum, Robsy (Karoshi) mentioned that, in theory, the memory access via paging is almost "infinite" (for example, 2 bytes are enough for accessing 1gb from 16kb pages)

    ReplyDelete
  5. I would also like to try out your ROMs on the real thing and make captures, once you/we decide on a 'convention' size. The trouble is that if you canibalize existing carts (like I did for my research on the Audio side for MESS/chipsounds), then you are stuck with 8/16KiB

    ReplyDelete
  6. Hello. Awesome. Thank you. I will try that on my Casio too. Anyone ever tried an AV mod on a Gdakken TV-Boy ?

    ReplyDelete