128kB FLASH Module

128KB-top.jpgSolderless 128kB FLASH module for the Acorn BBC Model B


This upgrade for the Model A/B provides 128kB of electrically erasable FLASH memory allowing upto eight paged ROM images to be resident while using only one paged ROM socket. FLASH is non-volatile so retains its contents if the power is switched off. Multiple modules can be installed for a total of 256kB of sideways ROM.

What is a paged ROM?

This adapter is ideal for people who want to keep their BBC as original as possible but expand it to make it more useful. Or people who want a simple plug and play memory expansion for the Model B.

Module Description

This adapter is designed to fit in one of the four ROM sockets on an unexpanded Model B. It has a 128kB FLASH chip on the top of the board and address decode logic on the bottom. It provides 4x 16kB paged ROMs from one physical socket in the Model B. With connection of the optional wire to a second socket in the Model B it provides 8x 16kB paged ROMs. 

This board is compatible with my 32kB RAM/ROM boards allowing total flexibility in your BBC upgrades.


  • Solderless - no permanent modifications required
  • Jumperless - no configuration required
  • Occuies one paged ROM socket on a model B (64kB mode)
  • Optionally occupies two paged ROM sockets on a model B (128kB mode)
  • Upto 8x 16kB in system erasable programmable sideways ROM
  • 100,000 erase/write cycles (typically)
  • 100 year data retention
  • Pre-loaded with programming software
  • Ultra low power & heat - negligible stress on the power supply

Kit Contents

Installation is very simple, solderless and completely reversible. The kit contains everything needed.

  • 128kB FLASH module
  • 2x IC clips for write strobe (NWDS) and ROM select (ROMSEL)
  • 1x Fly lead for 128kB mode (optional fit)
  • 2x wires to daisy chain multiple modules
  • Printed step by step instructions

Where to buy?

The modules are available for sale on eBay or direct through this website.

Contact me for more information