Editing Acorn Archimedes A310

{{Infobox computer
| name         = Acorn Archimedes A310
| image        = [[File:Acorn Archimedes A310 with mouse and keyboard.jpg|250px]]
| caption      = Acorn Archimedes A310
| manufacturer = Acorn Computers Ltd
| type         = Personal Computer
| release date = June 1987
| discontinued = 1989
| price        = £999 (excluding VAT, 1987)
| cpu          = ARM2 @ 8 MHz
| memory       = 1 MB RAM (expandable to 4 MB)
| storage      = 3.5" floppy drive (800 KB)
| sound        = 8-channel stereo, 8-bit
| os           = Arthur 0.30, later Arthur 1.20 (upgradeable to RISC OS 2)
| predecessor  = [[BBC Master]]
| successor    = [[Acorn Archimedes A3000]]
}}

The '''Acorn Archimedes A310''' was released in June 1987 alongside the A305 and A440 models. The A305 and A310 were launched in June 1987 and were the first RISC CPU-based computers in the world .

== Overview ==

The Archimedes was described as "the first RISC machine inexpensive enough for home use" and "the first commercially-available RISC-based microcomputer" . Launch prices of the first Archimedes range were A305 at £799, A310 at £999, A410 at £1,399 and A440 at £2,299 (excluding VAT and monitor) .

The Archimedes had an ARM processor (originally an abbreviation for 'Acorn RISC Machine'), which would become a vital part of many systems and still is today . The ARM2 32-bit CPU had 26-bit addressing and ran at 8 MHz .

== Hardware Specifications ==

=== Processor ===
The ARM2 processed about 3x as many instructions per clock cycle as the Intel 80386 and 40% more per clock cycle than the Motorola 68030 . Acorn's publicity claimed a performance rating of 4 MIPS, with Archimedes taking the crown as the fastest microcomputer in the world at the time, able to achieve 4.5 MIPS, although some claimed 18 MIPS .

=== Memory ===
The A310 had 1 MB memory standard . Despite the A310 being limited to 1 MB of RAM officially, several companies made upgrades to 2 MB and 4 MB, with the smaller upgrades augmenting the built-in RAM and the larger upgrades replacing it entirely .

=== Architecture ===
The A310 had an 8MHz ARM2, MEMC1 memory controller, 1MB RAM . The system used custom VLSI chips designed specifically for the Archimedes: ARM2 processor, MEMC memory controller, VIDC video/sound controller, and IOC input/output controller.

=== Display and Sound ===
The 32-bit system was fully capable of displaying 256 colors and 8-bit sounds . Graphical and sound power was a giant step forward over the BBC micro, with 256 colour modes (from a palette of 4096) and 8 channel 8-bit stereo sound .

== Operating System ==

There were a couple of publicly released versions of Arthur in 1987, 0.30 in June and 1.20 in September . Arthur 1.20 had a desktop written in BASIC which was very limited .

The operating system was in ROM, which meant the computer started very fast, though upgrades could only be carried out when the ROM was changed . For version 2 (October 1988), Arthur was renamed to RISC OS, which featured an updated GUI to enable co-operative multitasking of applications and a much more restrained colour scheme .

== Expansion ==

The 300 series required the addition of a backplane to gain expansion slot capabilities. A two slot backplane could be added to the 300 series as an official upgrade, with the possibility of 4-slot backplane being available from third parties . Common expansions included the Acorn AKA01 2 slot backplane, Acorn AKA05 ROM/RAM podule, and Acorn AKA10 I/O podule .
== Common Issues ==

In the Archimedes A310, Acorn specified three 100uF Tantalum capacitors rated at 16V as decoupling capacitors for the power supply on the motherboard. The voltage rating for these capacitors was under-specified, particularly for C37 which decouples the 12V line . This commonly caused power issues with machines failing to boot correctly.

The MEMC chip was revised and most Archimedes owners replaced it with the MEMC1a chip which, along with the PAL delivered an approximate 10% performance increase .

== See Also ==
* [[Acorn Archimedes A305]]
* [[Acorn Archimedes A440]]
* [[Acorn Archimedes A3000]]
* [[BBC Master]]

== External Links ==
* [https://chrisacorns.computinghistory.org.uk/Computers/A300.html Chris's Acorns: Acorn Archimedes A300 series]
* [https://www.computinghistory.org.uk/ Centre for Computing History]

[[Category:Acorn Computers]]