Just when you think you’ve seen everything with AVR microcontrollers here at Bits & Pieces, the 8-bit ideas just keep on coming! A Maker by the name of “Dan” has introduced an ingenious new innovation, a homebrew 8-bit computer running BASIC using a single ATmega1284P MCU.
Dan’s sleek design has the ability to generate composite video supported by multiple screens, as well as read PS/2 keyboard input. Running a slimmed down version of the BASIC language, called TinyBASIC, the 8-bit computer boasts over 7kb of SRAM which is available to write programs, while an 8KB EEPROM card (connected to the storage header) can be used to save full-size programs.
According to the Maker’s Hackaday page, “Many GPIO pins are available allowing connections to components such as LEDs, potentiometers, sensors and much more. A L7805 regulator is used to make the system more flexible with the power supply which can be used (compared to using no regulator at all) to power the system such as a 9V wall-mounted transformer or a 12V battery.”
“The computer is easy to assemble at home as all components are through-hole,” Dan notes on the simplicity of this design. “Once all the components from the component list have been gathered, they can all be soldered into place and the system is then ready for use. Simply connect a TV, PS/2 keyboard and power source such as a PP3 battery or wall-mounted PSU. If an EEPROM card is connected, set the jumper to the ‘C’ position to allow BASIC programs to be saved to the card or if internal EEPROM is going to be used, set the jumper to the ‘I’ position (note, the jumper is the same as the type used for IDE hard drive pins used to select master or slave mode so they can easily be found within old computers).