Diagnostic ROM and PCB

This is a replacement 16K ROM image to install on an Oric/Atmos mainboard to perform step-by-step test CPU/ULA/DRAM/VIA/PSG and associated circuitry. Includes schematic and PCB layout for optional external ROM/status LEDs/ULA replacement clock source and source code.


The source, documentation, and other files can be downloaded below.

Diagnostics ROM

Diagnostics PCB


2023/05/10: ROM revision 1.08k corrects a small initialization bug with the VIA chip.
Also provided: Standard (50Hz) version and 60Hz screen compatible version, both within the same .ZIP file

Source, documentation and pictures © 2009-2023 Mike Brown. Visit the website at http://oric.signal11.org.uk for the latest version and contact details.