Spare ROM/RAM cartridges for the Master and Electron

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On this page

• The need
  
• A solution
  
• Features and capabilities
  
• Availability
  

The need

By far the most common were the ROM/RAM cartridges which allowed easy loading and removal of extra memory without having to take the lid off the machine, effectively overcoming the operating system limit of a maximum of 16 sideways banks at once or limited number of sockets on the main PCB.

However, actually finding a supply of cartridges has become increasingly difficult as they have often become lost or damaged over the years.

A solution

The ROM/RAM cartridge with DOSFS fitted

Though the official ROM cartridges also came in matching moulded plastic case, the cartridges offered here further reduce complexity by making the PCB the shape of the cartridge itself - thus eliminating expensive plastic tooling costs. This also means that no tools are required to dismantle and change the chips over.

Features and capabilities

• option links to allow fast SRAM to be used instead of ROMs
• ability to use a number of different device types and geometries
• up to 32kbytes of memory per cartridge
• compatible with the Electron

In the default configuration the cartridge behaves like the original Acorn adapter, though the extra functionality requires the changing of one or more of the onboard 3 option links:

Survey of link positions

Boards use high quality turned pin IC sockets to reduce strain when inserting and removing devices, and to improve contact reliability over leaf style IC sockets.
The card edge fingers are gold plated to reduce contact resistance and oxide build up which would otherwise lead to poor contact and unreliability.

Availability

These cartridges are available now, and are offered in various different options depending on the application: