Editing Acorn Archimedes A5000 (section)

== Hardware Specifications ==

The A5000 motherboard represented mature Archimedes design, incorporating lessons from five years of production experience.

=== Processor Subsystem ===

The ARM3 processor configuration:
* '''Clock frequency:''' 25 MHz from 50 MHz crystal
* '''Cache:''' 4 KB unified instruction/data
* '''Cache organization:''' 64 lines of 16 words
* '''Cache timing:''' Single-cycle hit, 4-cycle miss
* '''Write strategy:''' Write-through
* '''Power consumption:''' 1.4W typical

The cache provided approximately 85% hit rate for typical applications, reducing memory bandwidth requirements substantially. This proved crucial given the memory system's shared bandwidth with video and sound DMA.

=== IDE Storage System ===

{| class="wikitable styled-table" style="width:90%; text-align:center;"
! Specification !! Details !! Performance
|-
| Controller || 82C711 COMBO chip || PIO Mode 2
|-
| Interface || 40-pin IDE connector || 16-bit data path
|-
| Transfer rate || 3.3 MB/s maximum || 1.5 MB/s typical
|-
| Drive options || 40/80/120 MB || Various manufacturers
|-
| File system || RISC OS 3 ADFS || Long filenames, 512 MB limit
|}

Common drive configurations:
* '''40 MB:''' Conner CP3044 or Western Digital WD93044
* '''80 MB:''' Conner CP3084 or Maxtor 7080A
* '''120 MB:''' Conner CP30124 or Seagate ST3144A

The IDE interface's simplicity improved reliability compared to SCSI, though with reduced performance and expandability.