ARM1 was the first ARM microarchitecture implemented by ARM Holdings (then Acorn Computers) as a research and development project for the BBC Computer Literacy Project. ARM1 was introduced in 1985 and was extended to be used as a coprocessor in the Acorn's BBC Micro microcomputers. ARM1 was distributed as an evaluation system and was never commercialized.

Overview

Main article: ARM's History

The ARM1 is Acorn Computers first microprocessor design. It was manufactured on VLSI Technology's 3 µm process using just 25,000 transistors. The ARM1 was the initial result of the Advanced Research and Development division Acorn Computers formed in order to advance the development of their own RISC processor. At the time the ARM1 was the simplest RISC processor produced.