RetroPie Turned Game Gear

Running vintage console emulators on a Raspberry Pi seems to be the thing all the cool kids are doing. The coolest RetroPie builds take a vintage console – usually of the Nintendo genus – stuff a Raspi in there somehow, and Bob’s your uncle. [Phil Herlihy] over at Adafruit is throwing his hat into the ring with a similar build. For this one, though, he’s using Sega’s oft-maligned Game Gear. He might actually get more than a few hours out of the battery with this one, and the battery is rechargeable, too. You can’t beat that.

The build begins with tearing down an old Game Gear, chopping up the PCB to save the button contact, and starting to fit all the components in there. The display is completely replaced with a 3.5″ composite display, a bit larger than the 3.2″ display found in a stock Game Gear. That’s not a problem, there’s a surprising amount of space behind the bezel, and if you’re good enough with an xacto blade and a file, it will look stock.

The rest of the components include an amplifier board, battery charge regulator, a 2500mAh LiPo, and a Teensy to read the buttons. There are a few modifications required for the Pi, but the finished device presents a USB port to the outside world; keep a keyboard by your side, and this is a portable Pi in every respect.

Developing a Sega Game Gear flash cartridge

[Gerry O’Brien] tackled his most recent project, designing a flash ROM cartridge for the Sega Game Gear, with great success. Above you can see the test rig he used to reverse engineer the communications between an original ROM chip and the circuit board that it came on. He removed the chip, soldered a ZIF socket to the pads, then used a DIP socket as an adapter for that chip. Connected to each pin is a test lead for a logic analyzer. That’s a heck of a lot of channels to decipher!

It turns out that the cartridges use Integrated Mapping (does anyone have a link explaining this?) so dropping in a flash memory chip is not an option; you need a memory bank controller. [Gerry’s] solution to this issue is twofold: you can etch your own board with a controller chip and ZIF socket for the flash chip, or you can modify a Sega Master System cartridge to use as an adapter board. We’ve got pictures of both methods after the break, as well as his five instructional videos walking us through the fabrication process.

This isn’t [Gerry’s] first time working with flash cartridges. We looked at his work with Game Boy ROMS earlier in the year.

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