Acorn A500 Prototype

The Acorn A500 was a pre-production ARM development computer built before the commercial Archimedes range. Roughly one hundred systems were produced in heavy metal desktop cases so software and hardware engineers could develop the ARM chipset and operating system.

Its ARM2, MEMC, VIDC and IOC architecture became the foundation of the A305 and A310 released in 1987.

Notable Features

• The main processing arrangement was Acorn ARM2 at 8 MHz.
• Its standard memory provision was 4MB.
• The model’s storage arrangement was 3.5-inch floppy drive and 20MB hard disc on documented systems.

Historical Significance

• Its ARM2, MEMC, VIDC and IOC architecture became the foundation of the A305 and A310 released in 1987.
• This entry represents a distinct processor, storage or enclosure design rather than a software bundle.

Collector’s Notes

• Surviving examples are scarce, and fitted boards, firmware and storage may differ from announced specifications.
• Original documentation, peripherals and prototype provenance are particularly important for specialist Acorn systems.

Specifications

Technical Information
Name	Acorn A500 Prototype
Manufacturer	Acorn Computers
Launched	Wednesday, January 1, 1986
Country	United Kingdom
CPU	Acorn ARM2 at 8 MHz
Units Sold
Operating System	ARX development environment; surviving machines may run RISC OS test builds
I/O	Video, audio, serial, parallel, Econet and four-slot podule backplane
Keyboard	Separate metal-cased keyboard and three-button mouse
Storage	3.5-inch floppy drive and 20MB hard disc on documented systems
Sound	Eight-channel sound through prototype VIDC hardware
Graphics	Prototype VIDC graphics architecture
Display	External RGB or monochrome monitor
ROM	Development ROM; later examples ran experimental RISC OS builds
RAM	4MB
CPU Speed	8 MHz