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The Zolatron 64 is my first attempt at a homebrew computer. It's based on the 65C02 microprocessor and was inspired in part by the Apatco 6502 breadboard computer and, later, by Ben Eater's 6502 build – although this project quickly diverged from both of those.

The Zolatron is a backplane design and the current boards plugged into the backplane are:

• Main processor board, with 65C02, 32KB RAM, 16KB ROM and 1MHz oscillator.
• Dual serial board, with one port being used for console access. Based on the NXP SC28L92 DUART.
• Parallel interface board, using a 62C22 VIA and intended for use with my dot matrix printer.
• Raspberry Pi board. This houses a Raspberry Pi Zero 2 which runs a terminal program (written by me in Go) to connect to the Zolatron through the serial port. It also runs the ZolaDOS program which communicates (via my own parallel protocol) with the Zolatron via a 65C22 VIA on the same board. This gives me persistent storage – basically acting like a hard drive.
• 65C22 VIA board driving a 20x4 character LCD display and five status LEDs.
• 65C22 VIA port providing two eight-bit user ports.

All the code is being written in 6502 assembly. I code in VS Code on the Mac and cross-assemble using Beebasm.