6502 SBC Rev 2 — Breadboard to PCB

In Progress Intermediate 6502 Computers Latest: v0.1.0
by Patrick · Apr 15, 2026 · 21 views · 2 followers · Est. cost: $45-60 · Est. time: 2-3 weekends · License: MIT
6502 breadboard homebrew KiCad retro SBC
2 votes

Links

</> GitHub Repository 📄 KiCad Design Files ▶ Ben Eater 6502 Series 📄 WDC 65C02 Datasheet 🛒 Buy on Mouser
Description Files (0) BOM (12) Build Log (3) Releases (2) Activity Comments (1)
v0.2.0-beta PCB Beta — Gerber Preview Pre-release
Patrick · Apr 10, 2026

Pre-release: PCB design files

KiCad schematic and PCB layout for review. Not yet fabricated — looking for feedback before ordering boards.

Changes from breadboard

  • Proper power filtering (bulk + per-chip decoupling)
  • Expansion header for future SPI/I2C
  • LED indicators on address bus A15/A14 for debug
  • Board dimensions: 100x80mm, 2-layer
v0.1.0 Breadboard Prototype ROM Latest
Patrick · Mar 20, 2026

First working ROM image

Contains:

  • EhBASIC 2.22 configured for 65C22 VIA serial I/O
  • Simple monitor with memory examine/deposit commands
  • 19200 baud, 8N1

Known Issues

  • Cold start only (no warm start vector yet)
  • No load/save to storage

How to burn

Use a TL866II+ programmer or similar EEPROM burner. Burn to AT28C256 starting at offset 0x4000 (maps to $C000 in the memory map).