Is a Microvision homebrew scene possible?

[atari2600land]

I was just wondering if the cartridges for the Microvision are rewritable, i.e. can anyone make a new Microvision cart out of an old one? I am also wondering how people wrote and put the games onto Microvision carts. If not a homebrew, how about an emulator? I've seen emulations of some games, but I'm thinking something more along the lines of OdyEmu, where you can choose which of the twelve original Odyssey carts you can play. And maybe if there's an emulator, people would start making games for the Microvision, at least to play on an emulator.

[Rickstilwell1]

I was just wondering if the cartridges for the Microvision are rewritable, i.e. can anyone make a new Microvision cart out of an old one? I am also wondering how people wrote and put the games onto Microvision carts. If not a homebrew, how about an emulator? I've seen emulations of some games, but I'm thinking something more along the lines of OdyEmu, where you can choose which of the twelve original Odyssey carts you can play. And maybe if there's an emulator, people would start making games for the Microvision, at least to play on an emulator.

That's actually a simulator, not an emulator so while the coding is similar it is not perfect.

[Compute]

The best case for microvision homebrew would probably be via simulation. From the Microvision FAQ http://www.handheldmuseum.com/MB/MicrovisionFAQ.txt:


Programming the Microvision is complicated by the fact that, unlike nearly every other cartridge based system, the CPU for each Microvision cartridge is included on the cartridge. Furthermore, the game code is included on the same chip.

Also:


Be forewarned, when working with Microvision cartridges, that they (or, more specifically, the built in CPUs) are very susceptible to electrostatic discharges.

In addition, the roms are masked, not PROMs or similar, so re-programming an existing cart would not be possible.

Because the system had its CPU on the cart, they were able to (and did) use different processors depending on what they could get, from the FAQ:

Blockbuster, Bowling, and Connect Four were actually programmed on both the TI TMS1100 and Intel (Signetics) 8021. This occurred because Signetics limited the number of chips Milton Bradley could by, forcing a shift to the Texas Instruments processor.

Not saying homebrew is impossible, but it's definitely not for the faint of heart. I think you would need to re-develop the platform to use a modern, readily-available, programmable chip. Something like a PIC or Arduino. You would need to drive the display processor and handle the inputs. You would also need to find a working Microvision ;)

[atari2600land]

Thanks for all the useful info. It's really interesting. By the way, I do have a working Microvision. I try to take the best gentle possible care of it so it stays that way, although I know it can't last forever.