Memory limitations mean that games are spread across several projects, but several hundred are supported overall.
Hardware consists of a Teensy 4.0 and ILI9341 or ST7789 SPI display plus an analog thumb joystick and three buttons. While pictures show a perfboard assembly, there is a KiCad PCB file in the repo, which should facilitate reproduction of the optional I2C keyboard, itself powered by a dedicated ATmega328P.
While sound is not yet supported, and emulation is limited to fairly old hardware, it’s still pretty cool to see Konami’s 1981 hit Scramble running on a DIY handheld. Watch more classics demoed in the videos below, and grab the source and pinout/PCB on GitHub.
ROM emulators have become extremely common for classic consoles like the NES and Game Boy, but what about earlier computers that also used edge-connector-style expansions?
HP Series 80 group member Tim Nye developed a Teensy 3.6-based ROM-emulating plug-in module that allows users of the early 1980s pre-PC HP 83/85 and 86/87 to select any of the systems’ available ROMs to be loaded from flash memory.
The board includes some unique features, such as a 6V level shifter to bridge the HP’s bus with the Teensy’s 3.3V logic, and a diode to prevent the HP’s 5V power from flowing via USB to a connected computer during programming. One interesting challenge was that the Teensy needs to boot before the HP, but the /HALT line on the HP’s bus can be driven by the Teensy to only permit the CPU to start once it’s ready.
The board appears to be a one-off with no information on purchasing or creating one’s own, but the HP Series 80 group is an active community, so drop them a note if you have a Series 80 with an empty expansion slot!