Acorn R225

The Acorn R225 was a lower-cost ARM3 Unix workstation intended to use network file servers rather than a large local hard disc. It ran RISC iX 1.2 and used the expandable A400-style desktop enclosure.

Together with the R260, it brought cached ARM3 performance to Acorn’s specialised Unix range.

Notable Features

• Acorn ARM3 at 25 MHz provides the system’s processing architecture.
• The standard memory configuration was 4MB; expandable.
• Storage was supplied as 800KB floppy drive; intended primarily for networked storage.

Historical Significance

• Together with the R260, it brought cached ARM3 performance to Acorn’s specialised Unix range.
• This record separates a genuine processor, memory, enclosure or storage model from software bundles and dealer-only configurations.

Collector’s Notes

• Confirm the exact model from its front badge and rear serial label because many Acorn systems were upgraded during their working lives.
• Original monitors, three-button mice, keyboards, expansion podules, manuals and installation media add historical value.

Specifications

Technical Information
Name	Acorn R225
Manufacturer	Acorn Computers
Launched	Monday, January 1, 1990
Discontinued	1992
Country	United Kingdom
CPU	Acorn ARM3 at 25 MHz
Units Sold
Operating System	RISC iX 1.2
I/O	Video, audio, serial, parallel, Ethernet and four podule slots
Keyboard	Separate keyboard and three-button mouse
Storage	800KB floppy drive; intended primarily for networked storage
Sound	Eight-channel, eight-bit stereo sound
Graphics	Acorn VIDC colour and monochrome graphics
Display	External high-resolution monitor
ROM	512KB boot ROM
RAM	4MB; expandable
CPU Speed	25 MHz