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Acorn Archimedes A300 Series

[A500 prototype]    [Archimedes]     [A400]


The A305 and A310 were launched in June 1987. It was the first RISC CPU based computer in the world. There were 2 models, the A305 and the A310. The A305 could be upgraded to the A310 specification.

Acorn also made some Archimedes which were packaged for specific applications, for example the Archimedes Music Workstation

The following models were produced [that I know of]:

Manuals and documents

  Here is the Acorn High Performance Computer System product brochure:
Acorn APP118 Archimedes

In July 1995 Personal Computer World published a long term (7 year) review of the A310 titled "Acorn Archimedes A310 ".

Here is the Archimedes 300 Series Module Level Service Manual.
Here is the Archimedes 300 Series Service manual Component Level Supplement.


The Archimedes A305 is the same as the A310, but with only 0.5MB RAM instead of the 1MB RAM in the A310. For further details see the A310 below.

I do not have an A305 and would like an unexpanded A305 running Arthur. [Wanted]


Here is the Acorn Archimedes 310 product brochure.
Archimedes 310

I bought my first A310 in December 1987, the A310 + a colour monitor cost me £1089 (I found the credit agreement for it recently). I immediately upgraded it with a second floppy disc drive, to make programming easier (1 system and 1 data disc). I used it as my main computer until 1989 when I bought an A410/1. Unfortunately I no longer have my original A310 but I have bought 3 from ebay, 1 in 2001 and 2 in 2003 and rebuilt them.

When I bought the A310, the OS was Arthur 0.30, shortly afterwards Acorn released the upgrade to Arthur 1.20. The Archimedes Arthur ROM Fitting Instructions ,  describe the upgrade and also make clear that Arthur 1.10 and Arthur 1.20 are the same. In 1988 RISC OS 2 was release and I upgraded my A310 to RISC OS 2. I still have the Arthur 0.30 and 1.20 ROMs. In fact I reused the Arthur 1.20 ROMs in the first A310 (see below) and after 18 years they still worked (as did the Arthur 0.30 ROMs).

The first A310  is typical of an Archimedes in late 1987/early 1988. I have restored it to this condition using parts from other systems and my own original Arthur ROMs, put aside when I intalled RISC OS 2 on my original A310. It has an 8MHz ARM2, MEMC1, 1MB RAM and runs Arthur 1.20. In addition I installed an Acorn AKA01 2 slot backplane, an Acorn AKA05 ROM/RAM podule, an Acorn AKA10 I/O podule. and a Beebug 5.25" disc interface (to allow a BBC disc drive to be connected to transfer data & programs).

Here is the Archimedes Welcome Guide for Arthur.
An archive of the Arthur 1.20 Welcome disc is available under Software.

The second A310 is typical of an A310 in late 1989. Once again it is restored from other parts and systems. It has an 8MHz ARM2, MEMC1a, 4MB and runs RISC OS 2. In addition I installed an Acorn AKA01 2 slot backplane, a Computer Concepts ROM podule and an Acorn AKD52 Hard Disc podule . I am still looking for a suitable ST506 hard disc.

Here is the Archimedes Welcome Guide for RISC OS 2 is available.
Archives of the RISC OS 2 Applications 1  disc, Applications 2 disc, Support disc and Extras disc are available under Software.

The third A310 is a much upgraded model and typical of an A310 in the early 1990s. It has a 25MHz ARM3 upgrade, MEMC1a, 4MB RAM and runs RISC OS 3.10. I have added an IFEL 4 slot backplane, Morley SCSI podule, an Acorn ROM podule, an HCCS user port and Mitsumi CDROM podule, an Irlam i-mage scanner podule (originally purchased for my A410/1) and a SCSI hard disc.

A310 (No. 1)


A310 (1) running Arthur 1.20, booted to BASIC V

A310 running Arthur 1.20, booted to BASIC V. Note the single floppy disc drive and the BBC style keyboard with red function keys. 

A310(1) running Arthur 1.2 desktop

A310 running Arthur 1.20 desktop

A310 running Arthur 1.20 desktop. The desktop was written in BASIC and was very limited. You can see the palette selector, calculator, notepad, clock, calendar and diary on the screen. The icon bar at the bottom has not come out in the picture, but has a floppy icon on the right which could format discs.  

A310 rear view

A310 rear view

 A310 rear view, showing the AKA10 I/O podule at the top, without the MIDI upgrade. The AKA05 ROM podule on the left middle and the Beebug 5.25" interface on the left middle. The usual I/O parts are at the bottom. 

A310 (1) with top cover off

A310 with the cover off

 A310 with the cover off, showing the AKA10 I/O podule in the bottom right and the cabling from the Beebug 5.25" interface going to the floppy drive in the top left. 

A310 with I/O podule removed

A310 with I/O podule removed

 A310 with I/O podule removed,  showing at the bottom left the ROM podule and next to it is the Beebug 5.25" disc interface. 

A310 motherboard

A310 motherboard.

 A310 motherboard, showing the 1 MB RAM at the top, with the keyboard connector on the top left. Below the RAM on the left is the large square ARM2 chip and the 4 ROMs on the middle left are the RISC OS 2 ROMs. The empty area on the middle right is where the Hard disc controller would be (fitted not fitted to A300 series). 

A310 (No.2)

A310 running RISC OS 2

A310 runing RISC OS 2

A310 running RISC OS 2.  

A310 rear view

A310 rear view

A310 rear view, showing the Acorn AKD52 hard disc podule visible in the middle left. The Computer Concepts ROM podule above it is not labelled.  

A310 with cover off

A310 with the cover off

A310 with the cover off, showing the podules on the bottom left, The Computer Concepts ROM/RAM podule is on top. The ARM2 chip can be seen below the floppy disc drive.  

A310 with podules removed

A310 with podules removed

 A310 with podules removed, the Acorn 2 slot backplane is visible above the 4 RISC OS ROMs in the middle on the left. 

A310 (No.3)

A310 running RISC OS 3

A310 (3) runs RISC OS 3.

A310 (3) runs RISC OS 3. Note the hard disc icon on the bottom left of the screen, this A310 has a hard disc.  

A310 rear view

A310 (3) rear view.

  A310 (3) rear view. On the top left is the Morley SCSI card with the HCCS user port below. In the middle is the Acorn ROM podule with the Irlam i-Mage scanner interface below.

A310 (3) with top off

A310 (3) with the cover off.

  A310 (3) with the cover off, in the middle bottom is the (empty) ROM podule. On the left (hidden by the ribbon cable) is the Morley SCSI podule. The hard disc is in the middle at the top connected by the ribbon cable to the SCSI podule. The ARM3 chip is visible in the top left underneath the floppy drive.

A310 (3) with cable removed

A310 (3) with the ribbon cable removed to show the Morley SCSI podule.

A310 (3) with the ribbon cable removed to show the Morley SCSI podule.  

A310 (3) motherboard

A310 (3) motherboard

A310 (3) motherboard. At the top is the IFEL 4MB upgrade. Below is the CJE Micros 25MHz ARM3 upgrade. Below the ARM3 is the RISC OS 3 ROM set in an IFEL carrier board.  



Serial No.27-ABK15-101229127-AKB15-101579327-AKB15-1002806
Unique Indentityn/an/an/a
Motherboard part no.276,000 Issue 2276,000 Issue 2276,000 Issue 2
CPU ModelVL2333-QCVL2333-QCVL86C020-PSGCP
CPU Clock8MHz8MHz25MHz
Memory ControllerMEMC1
IFEL A320340 Issue 1
IFEL A320340 Issue 3 
Memory Clock8MHz8MHz8MHz
Video ControlerVIDC1a
Floppy Disc DriveSony MP-F63W-00DSony MP-F63W-00DSony MP-F63W-00D
Hard Disc Controllern/aST506SCSI
Hard Disc Driven/an/a50MB
Quantum ProDrive LPS
Backplane ModelAcorn 2 slotAcorn 2 slotIFEL Backplane 305/310
Backplane part no.0176,040 Issue 1
 0176,040 Issue 1
BP2 Issue 4
Podule 0Acorn AKA05
ROM podule
0176,220 issue 1
Acorn AKD52
Winchester Podule
0276,240 issue 1
Morley 16-bit SCSI I/F
Batch 19
Serial No. 1347
Podule 1n/an/aAcorn AKA05
ROM podule
176,220 Issue 1
Podule 2Acorn AKA10
I/O podule
0276,200 issue 1
Computer Concepts
ROM/RAM podule
03015280 C3-80 
HCCS Ultimate user port
Podule 3n/an/aIrlam instruments
I-mage colour hand
scanner interface
Other upgradesBeebug 5.25" disc I/FNIFEL ROM carrier board
for RISC OS 3
OSArthur 1.20RISC OS 2.00RISC OS 3.10
OS Date25-Sep-875-Oct-8830-Apr-92
SICK v1.22
ARMSi v4.0