Tuesday, September 10, 2013

GameGear CPLD Cartridge

After researching PLD for my Atari dev cart, I remembered a time when I was trying to figure out a Gamegear flash cartridge. It is simple enough, but I had little luck because I was still very unlearned at the time when it came to Addressing bits.

Anyhow, I came across a Caesar's Palace Cartridge by Majesco which utilizes a CPLD! At the time I figured that I would never see one again, nor would I care at all if I were to. Now I care very much because they are pretty damn incredible devices!

The pictured CPLD is by Xilinx and now that I think about it, I really should locate it once more and dump the program on the CPLD. I dumped the game ROM, but it was exactly bit for bit the same as one I ... erm ... 'found' online.

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below is some pictuyres I took when I was trying to make that flash cart. I really wanted to play the Translated Phantasy Star on actual hardware, but I never got to before dropping the project.

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My drawing is flawed in that the highest address pins are connected to VCC and I programmed the ROM at the lowest bank which would place it at a point where the highest Address pins would all be low. Haha, silly me. had I simply filled in the extra ROM space with the ROm over and over again, it would have worked. I'll try again in the near future, no worries.

Below are more pictures of the bare board. Good times. lol
See how I ruined a few pins by pulling the pads up? That was a long time ago and I am proud to say that I can do much better.

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Even though the game gear is a terrible handheld, battery- and longevity-wise, it uses some great technology. Some things I like the most are the fact that it has all of the fingers on one side of the board, such as the gameboy. The atari the fingers on two sides, which gets annoying when designing a board. You'll also notice that every component is Surface Mounted; caps and Mask ROM included. This makes the size of the complete board much smaller and able to fit inside of the cartridge shell much more comfortably.

I may try to make a flash cartridge in the near future. One such cartridge that will use a CPLD so we can address higher memory addresses and will utilize saving features with a battery just because it is easier. If I stuck with those parameters, it should be able to support more official games as well as any homebrew titles.

I really like looking back on past projects and seeing how I could have done them better with what I know now. I am still rather new to EE, but I have every last bit of motivation and hunger for learning. I hope I can go back to school soon. I would really like to pursue my Master's degree next if not at least another BS degree.

Thanks for reading,
Jazz

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