Over the years, we have seen a large number of homemade handheld gaming systems that combine an AVR microcontroller, a few buttons, and a small OLED display. We even saw some of them turned into commercial products, such as Arduboy. They are simple, cheap, and using the right software will bring a lot of fun. But based on the MCU, most of them have the same limitation, that is, only one game can be held at any time.
But not a game card, by [Dylan Turner]. This handheld computer is Specially designed so that the game can be easily changed using a physical cassetteHowever, the system did not try to make the system’s microcontroller start the code from the external flash chip, but relocated the MCU to the removable cartridge. This may seem overkill, but considering how cheap the ATTINY84A is on each cartridge, it won’t be completely bankrupt.
Using the microcontroller on the cartridge, the only hardware remaining on the game card is the SSD1306 128×64 OLED display, buttons, and battery. This means that unless the game is plugged in, the handheld device is practically unusable, but this is also true for most early cassette-based gaming systems. On the other hand, it also opens up the possibility of producing ink cartridges with more powerful microcontrollers.
Using a different microcontroller for each game is a clever way, but it is not the only way to solve the problem. We have seen the community’s efforts to add expandable storage to Arduboy in the form of DIY ink cartridges, which eventually led to the development of an upgrade to the official flash memory chip for handheld devices.