8-Bit Homebrew Computer Designed Around an ATmega Microcontroller
The ATmega microcontroller is a versatile chip used for many different projects, including robotics, retro gaming, IoT devices and more.
Engineer Tom Goff used the popular microcontroller to drive his 8-bit homebrew computer that runs TinyBasic on an ATmega1284P-PU microcontroller. Goff chose the chip, which is outfitted with 8Kb of SRAM, 4Kb of EEPROM and 256 Kb of flash memory because TinyBasic doesn’t require a ton of space to run correctly.
Goff designed the PCB from scratch using press-and-peel transfer paper and the toner transfer method for etching. Once the copper side was completed, he made a silkscreen using conventional transfers created with a laser printer, making populating the board much more manageable.
The board includes an Arduino Nano as well, which provides a serial bus for the ATmega and connects to an RCA port in the rear of the case. It's also equipped with a pair of digital and analog headers to connect external devices and hardware.
The homebrew computer packs several other features, such as a piezo speaker, PS2 port, power LED, on/off toggle switch, and reset button. There's even an SD card slot, an FTDI header, and an on/off toggle switch for the Nano.
The hardware sits inside a laser-cut plywood enclosure with a handy acrylic lid that allows access to the components. Goff has uploaded an extensive walkthrough of the computer on his project page for those that would like to recreate his build.