Homebrew for Epoch Cassette Vision or Bandai Super Vision?

I've taken an interest in these oddball pre-Famicom consoles, and I was wondering if there is any contemporary (or past) homebrew/amateur programming for these systems? Flash carts? Technical documentation? Google is coming up empty.

And what is the equivalent term for 'homebrew' in Japanese?

自作ゲーム (jisaku geemu), meaning "homemade game" or "self-made game".

I don't know exactly about the Cassette Vision or Bandai things, but this Japanese guy's site has had some pretty detailed specs/info about old JP consoles & computers for a while: http://homepage3.nifty.com/takeda-toshiya/

edit: also this one: http://www43.tok2.com/home/cmpslv/

With the exception that we use "homebrew" to refer explicitly to games made on systems we really aren't supposed to work on without going through a strict curator (e.g. as with consoles), while 自作ゲーム is more generic (I've seen it used a lot to refer to free PC games, if Nico Nico is anything to go by). I mean, both INR and Custom Fighter (カスタムファイター) are labeled 自作ゲーム by their own developers even though they're just free PC games made by people in their spare time.

EDIT: also I hope the thread was about Super Cassette Vision, because the original Cassette Vision only provides the controllers and TV output - each cartridge included the whole "console" in it (CPU, etc.).

EDIT:

Yeah, the Super Cassette Vision doc is in that first site
http://homepage3.nifty.com/takeda-toshiya/scv/scv.pdf
You'll need to learn how to read Japanese though...

So it took my occasionally-repeated "make a TV tuner and plug in a PS3" joke literally. Would a famiclone be feasible?

I have no idea exactly what goes through the Cassette Vision, but I would imagine so. The video signal is generated entirely on the cartridge, so that part is clear, same with CPU and RAM (no idea about sound, but it's not generated on the console itself either). Your biggest problem would be the controllers being a completely different beast, but I would assume that if you were making the game exclusively for the Cassette Vision (or at least a dedicated version for it), you could just change the code accordingly.

Also skimming through the Super Cassette Vision doc. Holy shit 32×32 sprites o_O

(joke) Magic Floor when?

Epoch's handheld contemporary was also of the "CPU on the cartridge" type, the Epoch Game Pocket Computer, as was the predecessor Microvision.

No, actually, it wasn't. Here's my own page with the dope on that one: http://www.chrismcovell.com/GamePokekon/index.html

No, I was referring to the original Cassette Vision, and I didn't know it had a system-on-a-chip. That's why I was asking about info! Do you know of any technical documentation, or is that info from first-hand investigation?

And thanks, ccovell, for the links!

Oh, um, I think I know what's going on here

So, the console allows each game to use its own unique hardware, yet they reused the same hardware with every game? Huh... well I guess you could try figuring out how those games work. Sadly you won't be able to make homebrew on a stock console without sacrificing an existing cartridge or doing it in a FPGA or the like. (alternatively, make a console that has those innards already in it, but then it won't be stock anymore)

I have no idea if any info on that exists though.

I would bet good odds that it's 1- 5V and 2- has a parallel bus interface that would be easily adapted to work with any modern microcontroller that can address external memory.

I did find this link: http://d.hatena.ne.jp/redeel/20090508/1241808117 which show a mask ROM microcontroller

I also found someone's memoirs that contain the following text:


... Wait, he's already got this mostly together: he still has the documentation from the time on how he designed it

<eats my words>

The µPD777 is a single-chip video game processor. It natively emits component, s-video, and composite video, and per Mr. Oguchi's documentation, we are told the pinout of the 42-pin DIP it came in:


I think there's enough information on his web site to create an FPGA softcore, but I'm not confident. There's certainly no other way to program for it: it does not seem to have ever been released in a version that could address external or internal programmable memory.

This person has a picture of the inside of the base console.

and this person has (mostly) traced the 36-pin cart connector (to build a replacement base station)

and this person has taken things apart, but the pictures are less useful.

plgDavid's looked into this before. As has SlyDC.

The original Cassettevision was a little too primitive (Odyssey-II level) to draw my interest, not to mention Epoch's programmers' clear lack of imagination regarding games for it.

The only thing I thought was cool was the video hardware's ability to draw angular tiles somehow.

Dunno, seems like a normal character-based video mode with six possible characters (blank, filled, and four 90º triangles), and each character can only have its foreground color defined (the background is always black), and the palette is pretty lackluster too.

Not even going by any documentation here, just by how the games look.

The Epoch Cassette Vision audio chip seems very interesting! I've done some preliminary research on it and have found some datasheets, but I believe how it's wired to the board/carts makes it very limited in its capabilities. Nonetheless, it's capable of making some very interesting sounds and music.

Hello,

There is some thoughts on the real pinout of cassette vision CPU ? I doubt that pin 15 is the composite video signal. When I plug on a TV there is no image. Just a garbled screen.

Earlier in this thread is the research I did two years ago: viewtopic.php?p=176030#p176030

You probably need an amplifier of some sort to connect the VIDEO pin to a TV; it probably can't directly drive a 75Ω input. The original Cassette Vision used a big pile of transistors and a 4050 hex inverter IC.

Thanks, I already read this topic but pin 15 seem to be luminance not directly composite video.

The purpose is to add composite video to a Cassette Vision jr. who only has RF out.

Then you'll have to mix luma and chroma. This isn't exactly hard, but you may wish to reverse-engineer what the original mainboard is doing, and find where they're combined, instead of rebuilding it from scratch.

Alternatively, a TV with an S-video input...