Dumping Game Boy Cartridges Via The Link Cable Port

December 14, 2022 by Lewin Day 17 Comments

When it comes to vintage consoles like the Game Boy, it’s often nice to be able to dump cartridge ROMs for posterity, for archival, and for emulation. To that end, [Francis Stokes] of [Low Byte Productions] whipped up a rather unique method of dumping Game Boy carts via the link cable port.

The method starts by running custom code on the Game Boy, delivered by flash cart. That code loads itself into RAM, and then waits for the user to swap in a cart they wish to dump and press a button. The code then reads the cartridge, byte by byte, sending it out over the link port. To capture the data, [Francis] simply uses a Saleae logic analyzer to do the job. Notably, the error rate was initially super high with this method, until [Francis] realised that cutting down the length of the link cable cut down on noise that was interfering with the signal.

The code is available on GitHub for those interested. There are other ways to dump Game Boy cartridges too, of course.

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Repurposing A Toy Computer From The 1990s

October 14, 2019 by Tom Nardi 23 Comments

Our more youthful readers are fairly likely to have owned some incarnation of a VTech educational computer. From the mid-1980s and right up to the present day, VTech has been producing vaguely laptop shaped gadgets aimed at teaching everything from basic reading skills all the way up to world history. Hallmarks of these devices include a miserable monochrome LCD, and unpleasant membrane keyboard, and as [HotKey] found, occasionally a proper Z80 processor.

It started, as such things often do, with eBay. [HotKey] found that the second hand market is flooded with these decades-old educational gadgets, often selling for just a few bucks. As it turns out, children of the smartphone and tablet era don’t seem terribly interested in a “laptop” from 1991. At any rate, he ordered about a dozen different models and started tearing into them to see what made them tick.

He found that the VTech machines of around 20+ years old were using the Z80 processor, and what’s more, they shared a fairly standardized external cartridge interface for adding additional software or saving data. Upon attempting to dump some data from the cartridge port, [HotKey] discovered that it was actually connected to the computer’s main bus. He realized that with a custom designed cartridge, it should be able to take over the system and have it run his own code.

After more than a year of tinkering and talking to other hackers in the Z80 scene, [HotKey] has made some impressive headway. He’s not only created a custom cartridge that lets him load new code and connect to external devices, but he’s also added support for a few VTech machines to z88dk so that others can start writing their own C code for these machines. So far he’s created some very promising proof of concept programs such as a MIDI controller and serial terminal, but ultimately he hopes to create a DOS or CP/M like operating system that will elevate these vintage machines from simple toys to legitimate multi-purpose computers.

We’ve seen VTech hardware hacked in the past, but it’s generally been focused on the company’s more recent hardware such as the Linux-powered InnoTab. It will be interesting to see if these educational toys can fulfill some hacker’s dreams of having a cheap and portable box for Z80 tinkering.

Open Source SNES To USB Converter Lets You Emulate Legally

August 28, 2016 by Gerrit Coetzee 59 Comments

[Andrew Milkovich] was inspired build his own Super Nintendo cartridge reader based on a device we covered an eternity (in internet years) ago. The device mounts a real cartridge as a USB mass storage device, allowing you to play your games using an emulator directly from the cart.

This uses a Teensy++ 2.0 at its core. [Andrew] had to desolder the EEPROM pins from the SNES cartridge and reverse engineer the pinouts himself, but the end result was a device that could successfully read the cartridge without erasing it, no small accomplishment. The finished cartridge reader is build on some protoboard and we’d like to complement [Andrew] on his jumper routing on the underside of that board.

Of course, the experience of any console is just not the same without the original controller. So [Andrew] went a step further and made his own SNES controller to USB converter. This had the venerable Atmel ATmega328 at its core, and can be used separate from the cartridge reader if desired.