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Created page with "{{Infobox computer | name = Acorn Archimedes A440 | image = 250px | caption = Acorn Archimedes A440 | manufacturer = Acorn Computers Ltd | type = Personal Computer | release date = June 1987 | discontinued = 1989 | price = £2,499 (1987) | cpu = ARM2 @ 8 MHz | memory = 4 MB RAM | storage = 3.5" floppy drive (800 KB), 40 MB ST506 hard drive | display = 640×512 (16 colours), 640..."
 
Rewrite with real citations from the Archimedes 440 Service Manual, the 1987 price list and Chris Whytehead. Corrected: the GBP2,644 figure is the GBP2,641.60 inc-VAT base price; the R140 drive is 60 MB not 52-53 MB and it cost GBP3,500 ex VAT; measured A440 performance is 4.56 MIPS. Added the two AA alkaline backup cells with Acorn part numbers and the 1.4 V per cell check. Removed stripped-citation prose and unsourced 18 MIPS / 43 MB claims. Fixed red links.
 
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{{Infobox computer
{{Infobox computer
| name        = Acorn Archimedes A440
| name        = Acorn Archimedes A440 and A440/1
| image        = [[File:Acorn_Archimedes_A440.jpg|250px]]
| image        = [[File:Acorn_Archimedes_A440.jpg|250px]]
| caption      = Acorn Archimedes A440
| caption      = Acorn Archimedes A440
| manufacturer = Acorn Computers Ltd
| manufacturer = Acorn Computers Ltd
| type        = Personal Computer
| type        = Personal computer (three-box desktop)
| release date = June 1987
| release date = A440 June 1987 (available November 1987); A440/1 May 1989
| discontinued = 1989
| discontinued = A440 1989; A440/1 1991
| price        = £2,499 (1987)
| price        = A440 £2,299 ex VAT (£2,641.60 inc VAT); A440/1 £2,499 ex VAT
| cpu          = ARM2 @ 8 MHz
| cpu          = ARM2 @ 8 MHz
| memory      = 4 MB RAM
| memory      = 4 MB RAM
| storage      = 3.5" floppy drive (800 KB), 40 MB ST506 hard drive
| storage      = 3.5" floppy drive; 20 MB ST506 hard disc (A440), 50 MB (A440/1)
| display      = 640×512 (16 colours), 640×256 (256 colours), 1152×896 (monochrome)
| display      = Analogue RGB and high-resolution mono; up to 640×512 on a multisync
| sound        = 8-channel stereo, 8-bit logarithmic DAC
| sound        = 8-channel, 8-bit logarithmic (VIDC1a)
| dimensions  = 415 mm × 355 mm × 104 mm
| os          = A440: Arthur 1.2; A440/1: RISC OS 2.00
| weight      = 9.5 kg
| predecessor  = BBC Master series (no page yet)
| os          = Arthur 0.30 (later RISC OS 2.00)
| successor    = [[Acorn Archimedes A540]]
| predecessor  = [[BBC Master]]
| model        = AKB20 (A440), AKB44 (A440/1)
| successor    = [[Acorn Archimedes A440/1]], [[Acorn Archimedes A540]]
| codename    = Fairway
| model        = A305, A310, A410, A440
}}
}}
<templatestyles src="Template:StyledTable/styles.css" />
The '''Acorn Archimedes A440''' was the flagship of the original Archimedes range, announced in June 1987 with availability from November 1987. It had 4 MB of RAM and a 20 MB hard disc as standard, and it was the only 400-series machine Acorn is known to have actually shipped: the [[Acorn Archimedes A410|A410]] was announced and priced but slipped twice and probably never sold.<ref name="chris400">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/Computers/A400.html "Acorn Archimedes A400 Series"], Chris's Acorns / The Centre for Computing History.</ref>


The '''Acorn Archimedes A440''' was the flagship model of the original Archimedes range, released in June 1987. Featuring the maximum 4 MB RAM configuration and a 40 MB hard drive as standard, the A440 targeted professional users, universities, and high-end educational establishments requiring maximum performance from the revolutionary ARM architecture.
This page also covers the '''A440/1''' of May 1989, the MEMC1a-based replacement.


== Overview ==
== Prices ==


The A440 represented Acorn's vision of a professional workstation built around their ARM RISC processor. At £2,499, it cost nearly three times the entry-level A305 but delivered specifications that competed with systems costing substantially more. The 4 MB RAM configuration eliminated memory constraints that limited lesser models, while the 40 MB hard drive provided sufficient storage for serious development work and professional applications.
From Acorn's 1987 retail price list, ex VAT:<ref name="price87">Acorn Computers Limited, ''High Performance Computer Systems Retail Price List'' and ''Pricing'' sheet, 1987. Hosted on this wiki: [[Acorn Archimedes Retail Price List 1987]].</ref>


Acorn marketed the A440 primarily to universities, research institutions, and software development companies. The machine's ability to run Unix variants, combined with its exceptional price-performance ratio, attracted computer science departments seeking affordable workstations for teaching and research. The built-in BBC BASIC V with inline ARM assembler made it particularly attractive for systems programming education.
{| class="wikitable styled-table" style="width:75%; text-align:center;"
 
! Product code !! Configuration !! RRP ex VAT !! RRP inc VAT
== Architecture ==
 
The A440 utilized the complete Archimedes architecture without compromises imposed by cost reduction. All four SIMM slots contained 1M×9-bit modules, providing the maximum addressable memory for the MEMC memory controller. This configuration eliminated the memory bottlenecks that affected lower-specified models, particularly when running memory-intensive applications or high-resolution display modes.
 
=== Memory Architecture ===
 
{| class="wikitable styled-table" style="width:70%; text-align:center;"
! Aspect !! Specification !! Impact
|-
| Physical RAM || 4× 1M×9 SIMMs || 4,194,304 bytes total
|-
| Logical address space || 32 MB || MEMC limitation
|-
| Page size || 32 KB || Hardware translation
|-
| Protection || Read/write/execute || Per-page basis
|-
| Error detection || 9th bit parity || Hardware checking
|}
 
The MEMC controller implemented a Content Addressable Memory (CAM) for address translation, providing hardware memory protection without the complexity of a full Memory Management Unit. This design allowed zero-wait-state sequential access while maintaining protection boundaries between tasks.
 
== Hardware Configuration ==
 
The A440 motherboard was identical to other first-generation Archimedes models, with the differentiation entirely in fitted components and peripherals. This standardization reduced manufacturing costs while simplifying service and support.
 
=== System Board Components ===
 
The four custom VLSI chips operated in tight synchronization:
* '''ARM2:''' Executed instructions fetched from memory
* '''MEMC:''' Arbitrated between processor, video, sound, and refresh
* '''VIDC:''' Generated video timing and processed sound samples
* '''IOC:''' Managed I/O devices and system timers
 
Clock distribution derived from a single 24 MHz crystal, divided to generate:
* 8 MHz processor clock
* 16/24 MHz video pixel clocks
* 2 MHz I/O timing
* 250 kHz sound sample timing
 
=== Power Supply ===
 
The A440 required an enhanced power supply to support the full memory complement and hard drive:
 
{| class="wikitable styled-table" style="width:85%; text-align:center;"
! Component !! Current Draw !! Voltage !! Power
|-
| ARM2 + chipset || 1.8A || +5V || 9W
|-
| 4 MB RAM || 1.6A || +5V || 8W
|-
| 40 MB hard drive || 1.5A/0.8A || +12V/+5V || 22W
|-
| Motherboard logic || 0.8A || +5V || 4W
|-
| '''System total''' || 5.0A/1.5A || +5V/+12V || '''43W'''
|}
 
The linear power supply operated near its design limits, making adequate ventilation critical. The transformer-based design provided excellent regulation but generated substantial heat, contributing to component stress in poorly ventilated installations.
 
== Storage System ==
 
The A440's 40 MB hard drive represented substantial storage for 1987, exceeding many contemporary PC and Macintosh configurations. The ST506 interface, while not cutting-edge, provided adequate performance for contemporary software.
 
=== Drive Specifications ===
 
{| class="wikitable styled-table" style="width:90%; text-align:center;"
! Parameter !! MiniScribe 8438 || Rodime RO3055T || NEC D5146
|-
| Capacity || 40 MB || 45 MB || 40 MB
|-
| Cylinders || 615 || 872 || 615
|-
| Heads || 4 || 3 || 8
|-
| Sectors/track || 26 || 17 || 17
|-
| Average seek || 65ms || 28ms || 30ms
|-
| Rotation speed || 3600 RPM || 3600 RPM || 3600 RPM
|}
 
Different production runs used various drives based on availability, though all were configured as 40 MB to maintain consistency. The Rodime drives offered superior performance but suffered from higher failure rates than the robust MiniScribe units.
 
=== Controller Implementation ===
 
The ST506 controller podule occupied slot 0, implementing:
* '''Command set:''' Western Digital WD1010 subset
* '''Error correction:''' 32-bit ECC with retry
* '''Sector interleave:''' 3:1 optimal for 8 MHz ARM2
* '''Track buffering:''' 8 KB SRAM cache
* '''DMA support:''' Not implemented (programmed I/O)
 
The lack of DMA meant disk operations consumed processor cycles, though the ARM2's efficiency minimized the impact. Typical transfer rates reached 300-400 KB/s, adequate for contemporary applications.
 
== Display Capabilities ==
 
The 4 MB RAM configuration allowed full use of all display modes without memory constraints:
 
=== Mode Performance ===
 
{| class="wikitable styled-table" style="width:90%; text-align:center;"
! Mode !! Resolution !! Colors !! Memory Used !! Free RAM (4 MB)
|-
| 12 || 640×512 || 16 || 160 KB || 3.84 MB
|-
| 13 || 640×512 || 256 || 320 KB || 3.68 MB
|-
| 15 || 640×512 || 16 || 160 KB || 3.84 MB
|-
| 20 || 640×512 || 16 || 160 KB || 3.84 MB
|-
| 21 || 640×512 || 256 || 320 KB || 3.68 MB
|-
| 23 || 1152×896 || 2 || 128 KB || 3.87 MB
|}
 
Mode 21, impractical on 1 MB systems, ran comfortably on the A440 with sufficient memory for multiple applications. The high-resolution Mode 23 provided exceptional clarity for desktop publishing and CAD applications, though it required a multisync monitor.
 
== Software Environment ==
 
The A440's specifications enabled software categories impossible on lesser models:
 
=== Development Tools ===
 
Professional development environments thrived on the A440:
* '''Acorn Desktop C:''' Full ANSI C compiler with debugger
* '''Cambridge Lisp:''' Complete Common Lisp implementation
* '''Norcroft C:''' ARM's official C compiler
* '''Twin:''' Text editor with multiple buffers
* '''DDT:''' Desktop debugging tool
 
The 4 MB RAM allowed compilation of substantial programs without disk swapping, while the hard drive stored complete development environments with source code libraries.
 
=== Professional Applications ===
 
Commercial software leveraged the A440's capabilities:
* '''Impression:''' Professional desktop publishing
* '''Eureka:''' Mathematical equation solver
* '''ProArtisan:''' 24-bit image processing
* '''Sibelius:''' Music notation and composition
* '''Ovation:''' Document processing system
 
These applications required 2-4 MB RAM for practical operation, making the A440 the minimum viable platform for professional work.
 
=== Unix Variants ===
 
Several Unix implementations targeted the A440:
* '''RISC iX:''' Acorn's BSD 4.3-based Unix
* '''NetBSD:''' Community-supported port
* '''ARM Linux:''' Early Linux port
 
Unix operation required the full 4 MB RAM, with 2 MB considered absolute minimum. The A440 became a popular platform for Unix education due to its low cost compared to traditional workstations.
 
== Expansion Configuration ==
 
With three free podule slots after the hard drive controller, the A440 supported substantial expansion:
 
=== Professional Configurations ===
 
{| class="wikitable styled-table" style="width:85%; text-align:center;"
! Configuration !! Slot 1 || Slot 2 || Slot 3 || Use Case
|-
| Development || SCSI || Serial || Debugger || Software development
|-
| Publishing || SCSI || Scanner || Ethernet || Desktop publishing
|-
| Scientific || FPA || IEEE-488 || ADC || Data acquisition
|-
| Network || Ethernet || Serial || File server || Unix server
|-
| Multimedia || MIDI || Sampler || SCSI || Music production
|}
 
The podule bus operated at full processor speed, enabling high-performance expansions. Each slot provided independent interrupt lines, allowing multiple cards to operate simultaneously without conflicts.
 
== Performance Analysis ==
 
The A440 delivered workstation-class performance at personal computer pricing:
 
=== Benchmark Comparisons (1987) ===
 
{| class="wikitable styled-table" style="width:90%; text-align:center;"
! System !! Processor !! Dhrystone !! Price !! Price/Performance
|-
| Archimedes A440 || ARM2 8MHz || 4,100 || £2,499 || 1.64
|-
| Sun 3/50 || 68020 15MHz || 3,300 || £7,500 || 0.44
|-
| IBM PS/2 Model 80 || 386 16MHz || 3,500 || £4,995 || 0.70
|-
| Mac II || 68020 16MHz || 3,200 || £3,898 || 0.82
|-
| Amiga 2000 || 68000 7MHz || 1,100 || £1,495 || 0.74
|}
 
The A440's price-performance ratio exceeded all contemporary competitors, though software availability limited its market penetration.
 
== Manufacturing History ==
 
Production evolved through several distinct phases:
 
=== Production Variants ===
 
{| class="wikitable styled-table" style="width:85%; text-align:center;"
! Period !! PCB Issue !! Changes !! Volume
|-
| Jun-Oct 1987 || Issue 1 || Initial production || ~500 units
|-
|-
| Nov 1987-Mar 1988 || Issue 2 || Timing improvements || ~1,200 units
| AKB20 || A440, no monitor || £2,299.00 || £2,641.60
|-
|-
| Apr-Dec 1988 || Issue 3 || Cost reduction || ~1,800 units
| AKB20/AKF01 || A440 with mono monitor || £2,349.00 || £2,699.10
|-
|-
| Jan-Jun 1989 || Issue 3a || Final revision || ~1,000 units
| AKB20/AKF11 || A440 with colour monitor || £2,499.00 || £2,871.60
|}
|}


Total production remained under 5,000 units, reflecting the limited market for high-end ARM workstations. Educational institutions purchased approximately 60% of production, with the remainder split between commercial and research users.
The £2,299 base price already includes the 4 MB of RAM and the 20 MB hard disc — those are what define the model, not extras. A figure of "£2,644" sometimes quoted for a fully-specified A440 is the £2,641.60 '''inc VAT''' base price, not a higher specification.<ref name="price87" />
 
== Common Modifications ==
 
A440 owners frequently implemented enhancements:
 
=== Processor Upgrades ===
 
The ARM3 upgrade transformed system performance:
* '''Clock speed:''' 25-33 MHz versus 8 MHz
* '''Cache:''' 4 KB unified cache
* '''Performance:''' 4-5× improvement
* '''Compatibility:''' Full software compatibility
* '''Installation:''' Direct socket replacement
 
The cache particularly benefited the A440 by reducing memory bandwidth demands, allowing the video system more access cycles.
 
=== Storage Upgrades ===
 
ST506 drive limitations drove upgrade requirements:
* '''SCSI conversion:''' Lingenuity or Oak podules
* '''Larger drives:''' 100-500 MB SCSI drives
* '''Removable media:''' SyQuest or ZIP drives
* '''Tape backup:''' SCSI tape drives
 
SCSI conversion became essential as ST506 drives failed and replacements became unavailable.
 
=== Memory Enhancements ===
 
While 4 MB was the official maximum, third-party solutions existed:
* '''MEMC podule:''' Added 4-8 MB additional RAM
* '''Simtec upgrade::** 16 MB total with modified MEMC
* '''Shadow RAM::** Separated screen memory from main RAM
 
These upgrades primarily benefited Unix users, as RISC OS struggled to utilize memory beyond 4 MB effectively.
 
== Reliability Considerations ==
 
The A440's complexity and power consumption created specific failure patterns:
 
=== Component Failure Rates ===
 
Based on service records and user reports:
* '''Hard drives:''' 50% failure rate within 10 years
* '''Power supplies:''' 30% require capacitor replacement at 20 years
* '''Battery leakage:''' 80% leak if not replaced within 10 years
* '''Keyboard controller:''' 10% firmware corruption
* '''Custom chips:''' <1% failure rate
 
The custom VLSI chips proved remarkably reliable, with failures typically caused by external factors like power supply problems or static discharge.
 
=== Thermal Management ===
 
Heat dissipation remained problematic:
* '''Internal temperature:''' 45-50°C during operation
* '''Hot spots:''' Power supply, hard drive
* '''Ventilation:''' Single rear fan insufficient
* '''Component stress:''' Accelerated aging
 
Many users added supplementary cooling, though this increased noise levels. Proper ventilation extended component lifetime significantly.
 
== Unix Operation ==
 
The A440 became an important platform for Unix development and education:


=== RISC iX Requirements ===
== What made it different from the 300 series ==


Acorn's RISC iX demanded substantial resources:
The A440 is not a 300-series board with more memory. It uses a different motherboard, part 277,300, which carries a '''built-in ST506/MFM hard disc controller''' — the 300 series has an unpopulated area where that circuit would go and can only take a hard disc on a podule.<ref name="chris400" /><ref name="chris300">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/Computers/A300.html "Acorn Archimedes A300 Series"], Chris's Acorns / The Centre for Computing History. Machine-by-machine specification tables, part numbers and measured benchmark figures.</ref>
* '''Minimum RAM:''' 4 MB (8 MB recommended)
* '''Disk space:''' 50 MB minimum installation
* '''Display::** High-resolution monitor required
* '''Performance::** Adequate for single user


RISC iX provided a complete BSD 4.3 environment with X Windows, making the A440 an affordable Unix workstation for education.
It also ships with a '''four-slot backplane''' (part 0277,040) as standard, where the 300 series has no expansion slots at all until an optional two-slot backplane is fitted.<ref name="chris400" />


=== NetBSD Support ===
Unlike the A305 and A310, the A440 is not a BBC Microcomputer. Its keyboard has neither the red function keys nor the BBC logo above the numeric keypad.<ref name="chris400" />


The NetBSD project maintained A440 support:
== Hardware ==
* '''First release::** NetBSD 1.0 (1994)
* '''Final release::** NetBSD 1.6 (2002)
* '''Memory required::** 4 MB minimum
* '''Installation::** Network or SCSI tape


NetBSD extended the A440's useful life, providing modern Unix capabilities on vintage hardware.
* '''ARM2''' (VLSI VL2333-QC) at 8 MHz, 32-bit with 26-bit addressing, with the '''MEMC1''' (VL2304) memory controller, '''VIDC1a''' (VL2303A) video and sound controller and the IOC<ref name="chris400" />
* '''4 MB''' of DRAM, the maximum a single MEMC addresses<ref name="chris400" />
* '''20 MB ST506 hard disc''' on the on-board MFM controller; Chris Whytehead's machine carries a Tandon TM 362<ref name="chris400" />
* '''Sony MP-F63W-00D''' 3.5-inch floppy drive<ref name="chris400" />
* Four podule slots on the standard backplane<ref name="chris400" />
* Screen modes and video output levels are the same as the 300 series — see [[Acorn Archimedes A305#Display]]<ref name="sm300">Acorn Computers Limited, ''Archimedes 300 Series Module Level Service Manual'', part number 0476,140, Issue 1, April 1988. Section 1.2 Technical Specification, section 5 Connectors, interfaces, links and test points, and appendices 7.1 and 7.2. Hosted on this wiki: [[Archimedes 300 Series Service Manual]].</ref>


== Educational Impact ==
Acorn quoted 4 MIPS for the Archimedes generally; the measured figure for Chris Whytehead's A440 under RISC OS 2.00 is '''4.56 MIPS''' on ARMSi v4.0 and 5,383 Dhrystones per second.<ref name="chris400" /> Claims of 18 MIPS that appear in some contemporary reporting are not supported by any measurement on a documented machine.


Universities adopted the A440 for teaching and research:
== Backup batteries ==


=== Computer Science Education ===
The A440 uses '''two LR06 (AA size) 1.5 V manganese alkaline cells''' fitted inside the main unit, which Acorn specified for replacement once a year. They are Acorn part 0817,005, in battery holder assembly 0176,009, wired to connector PL11 on the main PCB. Acorn's own service check is that each cell should read above 1.4 V.<ref name="sm440">Acorn Computers Limited, ''Archimedes High Performance Computer Systems Model 440 Service Manual'', part number 0476,155, Issue 1, November 1988. Hosted on this wiki: [[Archimedes 440 Service Manual]].</ref>


The A440 excelled in teaching fundamental concepts:
They are not NiCd. Alkaline cells left in place for decades leak potassium hydroxide; the battery pack is clearly visible in the top-right of the case in photographs of surviving machines, close to the fan.<ref name="chris400" /> Remove them and inspect the holder and board before powering a stored machine — see [[Battery Explosion, Capacitor or Corrosion Damage]].
* '''Architecture::** RISC principles clearly demonstrated
* '''Assembly language::** Clean ARM instruction set
* '''Operating systems::** Source code available
* '''Compiler design::** Simple target architecture


The built-in assembler and BBC BASIC integration allowed immediate experimentation with ARM code, facilitating hands-on learning.
== Operating system ==


=== Research Applications ===
The A440 shipped with '''Arthur 1.2'''.<ref name="chris400" /> Arthur's desktop was written in BASIC and was very limited. RISC OS 2.00, dated 5 October 1988, replaced Arthur and is a ROM-set swap on this board; most surviving A440s have been taken at least that far, and many to RISC OS 3.10 or 3.11.<ref name="chris400" /><ref name="chris300" />


Research groups utilized A440 systems for:
== The A440/1 (1989) ==
* '''Parallel processing::** Networks of A440s
* '''Language development::** Experimental compilers
* '''Graphics research::** Custom display modes
* '''Real-time systems::** Predictable timing


The open architecture and comprehensive documentation enabled innovative research projects impossible on proprietary systems.
In May 1989 Acorn replaced the 400 series with the A4x0/1 range, whose main change was the MEMC1a memory controller — Acorn described the gain as "a slight performance improvement".<ref name="chris4001">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/Computers/A4001.html "Acorn Archimedes A400/1 Series"], Chris's Acorns / The Centre for Computing History.</ref> The A440/1, product code AKB44, had 4 MB of RAM and a 50 MB ST506 hard disc at £2,499 ex VAT, alongside the £1,199 [[Acorn Archimedes A410|A410/1]] and the £1,699 [[Acorn Archimedes A420|A420/1]].<ref name="chris4001" />


== General Maintenance ==
The A440/1 uses the Acorn Universal Board (part 0283,000) shared with the rest of the /1 range, with an HD63463P8 MFM controller, and the 0283,040 four-slot backplane.<ref name="chris4001" /> Its backup batteries are the same two AA alkaline cells, on connector PL10.<ref name="sm4001">Acorn Computers Limited, ''Acorn A400/1 &amp; R140 Service Manual'', 1989. Hosted on this wiki: [[Acorn A400-1 and R140 Service Manual]].</ref>
{{Main|Acorn Archimedes A440 General Maintenance}}


Maintenance priorities reflect the A440's complexity and age. Hard drive monitoring remains critical, listening for bearing noise or seek irregularities indicating impending failure. Power supply maintenance includes annual capacitor inspection and preemptive replacement of the main filter capacitor. The ST506 controller podule requires edge connector cleaning to prevent intermittent disk errors. Thermal management demands regular cleaning of air vents and verification of fan operation. Battery replacement every 5 years prevents alkaline leakage onto the motherboard.
Sources differ on the A440/1's hard disc size: Chris Whytehead's range description says 50 MB, his A440/1 section says 53 MB, and his product-code index says 20 MB.<ref name="chris4001" /><ref name="chrisarc">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/Computers/Archimedes.html "Archimedes"], Chris's Acorns / The Centre for Computing History. Acorn product-code list for the Archimedes range.</ref> Acorn appears to have shipped more than one drive over the model's life, so treat any single figure as approximate and check the drive in the machine.


== Troubleshooting ==
Badges and serial numbers on this range frequently disagree. Chris Whytehead's A440/1 carries serial number 27-AKB40-1007658 — an A410/1 code — on a machine with 4 MB and a hard disc, apparently a dealer upgrade with the front label changed.<ref name="chris4001" />
{{Main|Acorn Archimedes A440 Troubleshooting}}


Diagnostic procedures begin with power supply verification, as marginal voltages cause various symptoms. Hard drive problems manifest as boot failures, data corruption, or controller timeouts. Memory errors produce application crashes or system hangs, diagnosed through systematic testing. Video corruption suggests VIDC timing issues or memory conflicts. The diagnostic ROM, if available, provides comprehensive hardware testing. Component-level troubleshooting requires oscilloscope verification of clock signals and logic analyzer examination of bus activity.
== R140: the Unix version ==


== Capacitor Replacement Guide ==
The '''R140''' was Acorn's entry into the Unix workstation market, built on the same hardware as the A440: an ARM2 and 4 MB of memory, but with a larger '''60 MB''' ST506 drive. RISC OS 2 sat in ROM and was used only for the initial boot, which then loaded the disc-based RISC iX BSD Unix system.<ref name="riscix">Whytehead, Chris. [https://chrisacorns.computinghistory.org.uk/RISCiXComputers.html "RISC iX Computers"], Chris's Acorns / The Centre for Computing History. R140, R225 and R260 specifications and prices.</ref>
{{Main|Acorn Archimedes A440 Capacitor Replacement Guide}}


The enhanced power supply contains additional capacitors: main filter (8200µF 25V), auxiliary filters (2200µF 16V ×4), and switching regulation (100µF 25V ×6). Motherboard capacitors match other Archimedes models (100µF 16V ×6, 47µF 16V ×8, 22µF 25V ×4). The ST506 controller requires precision capacitor replacement to maintain timing accuracy. High-voltage primary-side capacitors demand appropriate safety precautions during replacement.
At launch the R140 without a monitor cost '''£3,500 ex VAT''' against the A440's £2,299; the AKA25 Ethernet podule was £599 and the AKA30 SCSI adapter £299.<ref name="riscix" /> Acorn documented the R140 alongside the A400/1 range in the [[Acorn A400-1 and R140 Service Manual]] hosted here.<ref name="sm4001" />


== Market Reception ==
== Maintenance and repair ==


The A440 faced a challenging market position. While technically impressive, the high price limited sales to institutions and enthusiasts. Software availability remained the primary barrier to broader adoption. The education market provided steady but limited demand. Commercial markets largely ignored the platform despite superior performance.
* '''Remove the AA alkaline cells''' and inspect the holder and the board around it.
* '''Check the cells against Acorn's own limit''' of 1.4 V per cell if you are diagnosing lost configuration.<ref name="sm440" />
* '''ST506/MFM drives''' are usually the dead component on a surviving machine; see [[Hard Drive Maintenance and Repair]].
* '''Floppy drive''' — see [[Floppy Drive Repair]].
* '''Tools''' — see [[Recommended Tools]].


Competition from established workstation vendors and emerging PC compatibles eroded the A440's market position. By 1989, 386-based systems matched A440 performance at lower prices with vastly superior software selection. The A440's discontinuation reflected Acorn's recognition that the high-end workstation market required resources beyond their capabilities.
Acorn's fault-finding, links and test points, parts lists and circuit diagrams for the A440 are in the [[Archimedes 440 Service Manual]] hosted here; for the A440/1 they are in the [[Acorn A400-1 and R140 Service Manual]].


== Legacy ==
== See also ==


The A440 demonstrated the potential of RISC architecture in desktop systems, influencing subsequent processor development. While commercial success eluded it, the technical achievements were substantial. The system proved that small companies could challenge established players through innovative design.
* [[Acorn Archimedes A305]] and [[Acorn Archimedes A310]] — the 1987 300 series
* [[Acorn Archimedes A410]] — the never-sold A410 and the A410/1
* [[Acorn Archimedes A420]] — the A420/1
* [[Acorn Archimedes A540]] — the 1990 flagship that replaced it
* [[Archimedes 440 Service Manual]]


Modern retrocomputing enthusiasts value A440 systems for their historical significance and build quality. However, failing hard drives and power supplies make restoration challenging. The scarcity of ST506 drives necessitates modern storage solutions, typically SCSI or IDE adaptations.
== References ==


The A440's influence extended beyond its commercial life through the engineers and students who learned on these systems. Many UK technology leaders trace their understanding of computer architecture to hands-on experience with Archimedes systems, particularly the flagship A440.
<references />


== See Also ==
{{Navbox-AcornComputers|state=collapsed}}
* [[Acorn Archimedes A305]]
* [[Acorn Archimedes A310]]
* [[Acorn Archimedes A410]]
* [[Acorn Archimedes A440/1]]
* [[Acorn Archimedes A540]]


[[Category:Acorn Computers]]
[[Category:Acorn Computers]]
{{Navbox-AcornComputers}}

Latest revision as of 02:50, 23 September 2026

Acorn Archimedes A440 and A440/1
Acorn Archimedes A440
Specifications
ManufacturerAcorn Computers Ltd
TypePersonal computer (three-box desktop)
ReleasedA440 June 1987 (available November 1987); A440/1 May 1989
DiscontinuedA440 1989; A440/1 1991
Intro priceA440 £2,299 ex VAT (£2,641.60 inc VAT); A440/1 £2,499 ex VAT
CPUARM2 @ 8 MHz
Memory4 MB RAM
Storage3.5" floppy drive; 20 MB ST506 hard disc (A440), 50 MB (A440/1)
DisplayAnalogue RGB and high-resolution mono; up to 640×512 on a multisync
Sound8-channel, 8-bit logarithmic (VIDC1a)
OS / FirmwareA440: Arthur 1.2; A440/1: RISC OS 2.00
PredecessorBBC Master series (no page yet)
SuccessorAcorn Archimedes A540
Model no.AKB20 (A440), AKB44 (A440/1)

The Acorn Archimedes A440 was the flagship of the original Archimedes range, announced in June 1987 with availability from November 1987. It had 4 MB of RAM and a 20 MB hard disc as standard, and it was the only 400-series machine Acorn is known to have actually shipped: the A410 was announced and priced but slipped twice and probably never sold.[1]

This page also covers the A440/1 of May 1989, the MEMC1a-based replacement.

Prices

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From Acorn's 1987 retail price list, ex VAT:[2]

Product code Configuration RRP ex VAT RRP inc VAT
AKB20 A440, no monitor £2,299.00 £2,641.60
AKB20/AKF01 A440 with mono monitor £2,349.00 £2,699.10
AKB20/AKF11 A440 with colour monitor £2,499.00 £2,871.60

The £2,299 base price already includes the 4 MB of RAM and the 20 MB hard disc — those are what define the model, not extras. A figure of "£2,644" sometimes quoted for a fully-specified A440 is the £2,641.60 inc VAT base price, not a higher specification.[2]

What made it different from the 300 series

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The A440 is not a 300-series board with more memory. It uses a different motherboard, part 277,300, which carries a built-in ST506/MFM hard disc controller — the 300 series has an unpopulated area where that circuit would go and can only take a hard disc on a podule.[1][3]

It also ships with a four-slot backplane (part 0277,040) as standard, where the 300 series has no expansion slots at all until an optional two-slot backplane is fitted.[1]

Unlike the A305 and A310, the A440 is not a BBC Microcomputer. Its keyboard has neither the red function keys nor the BBC logo above the numeric keypad.[1]

Hardware

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  • ARM2 (VLSI VL2333-QC) at 8 MHz, 32-bit with 26-bit addressing, with the MEMC1 (VL2304) memory controller, VIDC1a (VL2303A) video and sound controller and the IOC[1]
  • 4 MB of DRAM, the maximum a single MEMC addresses[1]
  • 20 MB ST506 hard disc on the on-board MFM controller; Chris Whytehead's machine carries a Tandon TM 362[1]
  • Sony MP-F63W-00D 3.5-inch floppy drive[1]
  • Four podule slots on the standard backplane[1]
  • Screen modes and video output levels are the same as the 300 series — see Acorn Archimedes A305#Display[4]

Acorn quoted 4 MIPS for the Archimedes generally; the measured figure for Chris Whytehead's A440 under RISC OS 2.00 is 4.56 MIPS on ARMSi v4.0 and 5,383 Dhrystones per second.[1] Claims of 18 MIPS that appear in some contemporary reporting are not supported by any measurement on a documented machine.

Backup batteries

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The A440 uses two LR06 (AA size) 1.5 V manganese alkaline cells fitted inside the main unit, which Acorn specified for replacement once a year. They are Acorn part 0817,005, in battery holder assembly 0176,009, wired to connector PL11 on the main PCB. Acorn's own service check is that each cell should read above 1.4 V.[5]

They are not NiCd. Alkaline cells left in place for decades leak potassium hydroxide; the battery pack is clearly visible in the top-right of the case in photographs of surviving machines, close to the fan.[1] Remove them and inspect the holder and board before powering a stored machine — see Battery Explosion, Capacitor or Corrosion Damage.

Operating system

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The A440 shipped with Arthur 1.2.[1] Arthur's desktop was written in BASIC and was very limited. RISC OS 2.00, dated 5 October 1988, replaced Arthur and is a ROM-set swap on this board; most surviving A440s have been taken at least that far, and many to RISC OS 3.10 or 3.11.[1][3]

The A440/1 (1989)

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In May 1989 Acorn replaced the 400 series with the A4x0/1 range, whose main change was the MEMC1a memory controller — Acorn described the gain as "a slight performance improvement".[6] The A440/1, product code AKB44, had 4 MB of RAM and a 50 MB ST506 hard disc at £2,499 ex VAT, alongside the £1,199 A410/1 and the £1,699 A420/1.[6]

The A440/1 uses the Acorn Universal Board (part 0283,000) shared with the rest of the /1 range, with an HD63463P8 MFM controller, and the 0283,040 four-slot backplane.[6] Its backup batteries are the same two AA alkaline cells, on connector PL10.[7]

Sources differ on the A440/1's hard disc size: Chris Whytehead's range description says 50 MB, his A440/1 section says 53 MB, and his product-code index says 20 MB.[6][8] Acorn appears to have shipped more than one drive over the model's life, so treat any single figure as approximate and check the drive in the machine.

Badges and serial numbers on this range frequently disagree. Chris Whytehead's A440/1 carries serial number 27-AKB40-1007658 — an A410/1 code — on a machine with 4 MB and a hard disc, apparently a dealer upgrade with the front label changed.[6]

R140: the Unix version

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The R140 was Acorn's entry into the Unix workstation market, built on the same hardware as the A440: an ARM2 and 4 MB of memory, but with a larger 60 MB ST506 drive. RISC OS 2 sat in ROM and was used only for the initial boot, which then loaded the disc-based RISC iX BSD Unix system.[9]

At launch the R140 without a monitor cost £3,500 ex VAT against the A440's £2,299; the AKA25 Ethernet podule was £599 and the AKA30 SCSI adapter £299.[9] Acorn documented the R140 alongside the A400/1 range in the Acorn A400-1 and R140 Service Manual hosted here.[7]

Maintenance and repair

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  • Remove the AA alkaline cells and inspect the holder and the board around it.
  • Check the cells against Acorn's own limit of 1.4 V per cell if you are diagnosing lost configuration.[5]
  • ST506/MFM drives are usually the dead component on a surviving machine; see Hard Drive Maintenance and Repair.
  • Floppy drive — see Floppy Drive Repair.
  • Tools — see Recommended Tools.

Acorn's fault-finding, links and test points, parts lists and circuit diagrams for the A440 are in the Archimedes 440 Service Manual hosted here; for the A440/1 they are in the Acorn A400-1 and R140 Service Manual.

See also

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References

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  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Whytehead, Chris. "Acorn Archimedes A400 Series", Chris's Acorns / The Centre for Computing History.
  2. ↑ 2.0 2.1 Acorn Computers Limited, High Performance Computer Systems Retail Price List and Pricing sheet, 1987. Hosted on this wiki: Acorn Archimedes Retail Price List 1987.
  3. ↑ 3.0 3.1 Whytehead, Chris. "Acorn Archimedes A300 Series", Chris's Acorns / The Centre for Computing History. Machine-by-machine specification tables, part numbers and measured benchmark figures.
  4. ↑ Acorn Computers Limited, Archimedes 300 Series Module Level Service Manual, part number 0476,140, Issue 1, April 1988. Section 1.2 Technical Specification, section 5 Connectors, interfaces, links and test points, and appendices 7.1 and 7.2. Hosted on this wiki: Archimedes 300 Series Service Manual.
  5. ↑ 5.0 5.1 Acorn Computers Limited, Archimedes High Performance Computer Systems Model 440 Service Manual, part number 0476,155, Issue 1, November 1988. Hosted on this wiki: Archimedes 440 Service Manual.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Whytehead, Chris. "Acorn Archimedes A400/1 Series", Chris's Acorns / The Centre for Computing History.
  7. ↑ 7.0 7.1 Acorn Computers Limited, Acorn A400/1 & R140 Service Manual, 1989. Hosted on this wiki: Acorn A400-1 and R140 Service Manual.
  8. ↑ Whytehead, Chris. "Archimedes", Chris's Acorns / The Centre for Computing History. Acorn product-code list for the Archimedes range.
  9. ↑ 9.0 9.1 Whytehead, Chris. "RISC iX Computers", Chris's Acorns / The Centre for Computing History. R140, R225 and R260 specifications and prices.


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