|This is the discussion page for the acorn/microarchitectures/arm3 page.|
25 Mhz ARM3 was standard in the Acorn A5000, and as upgrades for the Acorn Archimedes range. 33 Mhz ARM3 was used in the 'Alpha' edition of the A5000. 30 Mhz ARM3 was used in early Acorn A540. I believe the ARM3 in the Acorn A4 runs at 26 Mhz.
All above use a plastic package.
At some point Acorn had ordered a batch of ceramic ARM3s, to operate at 36 Mhz. Acorn didn't retain them to use in their machines, and sold them to a company named Ground Control, which in turn resold them to various third party companies, which sold them as CPU upgrades.