Twin ROMs Mod
This is a way to fit a second 27128 ROM/EPROM inside an Oric or Atmos to allow manual selection between Oric (V1.0) and Atmos (V1.1) BASIC, or any other firmware you may wish to load. It's a different method to the ROMDIS modification published elsewhere. Includes schematic and pictures.
Documentation (PDF) format) can be downloaded below.
Source, documentation and pictures © 2009-2018 Mike Brown. Visit the website at http://oric.signal11.org.uk for the latest version and contact details.