Acorn Archimedes A410/1 with 8MB RAM

This is the second of my Archimedes A410/1 machines which I purchased in October 2013 through ebay. It features an IFEL 36MHz ARM3 processor upgrade and a Simtec 4-8MB RAM upgrade along with a Simtec 16-bit IDE podule hosting a 4GB CF HDD.

Archimedes A410/1 with an 8MB RAM expansion

Due to the extra memory and the fastest ARM3 processor ever made that this A410/1 contains, it is the most flexible and usable of the original Archimedes family computers in the Retro-Kit collection. The Simtec RAM upgrade effectively doubles the maximum memory that the Archimedes architecture supports. This gives RISC OS the breathing space that it needs to run some of the more memory hungry applications when the machine is also running a Uniboot installation which is required for modern networking. The Uniboot installation is itself a drain on memory resources because it replaces (soft-loads) many of the original RISC OS 3 ROM modules and adds many extra modules to support TCP/IP networking. With the extra RAM and faster processor, RISC OS can have a few extra home comforts installed to make life easier, the screenshot below shows a backdrop, !AppsClock and !Mode? running along with all those extra hard drive partitions being available in the IconBar.

The RISC OS 3.11 desktop running in MODE 31 on the A410/1 with extra applications in the Icon Bar

Judging by some of the files found on the original SCSI hard drive, the machine was still in service as late as 1999, a full 10 years after it was originally manufactured.

Finally, this particular Archimedes has a twin which is owned by BeebMaster and you can see it by visiting his site. Both of these machines appear to have been bought by the same school in 1989 or 1990 and they received significant upgrades in 1991 when they were upgraded to have very similar specifications to each other.

In use

This machine has quickly become my primary development platform for RISC OS 3 projects as it has the performance and capacity to run an full network stack and an extended development suite with plenty of resources to spare.

Typically the development applications I use on this machine are !Zap for the text editor, !extASM for the ARM assembler and !ARMalyser to analyse the code produced. ARMalyser uses around 1MB of RAM when performing analysis so the extra RAM in this machine means that I don't have to close applications in order to make room for ARMalyser.

This machine is also set up as Econet station 235 so that it can be used as a printer server for the other machines on the network. It is connected to an Acorn JP-150 ink-jet printer and also a Xerox Phaser 8400 using the RemotePrinterFS module to provide TCP/IP network printing capabilities.

Expansions in this A410/1

Originally, the machine had an issue 2 Oak SCSI podule and large capacity (for the time) SCSI hard drive which I have removed due to reliability issues of the original SCSI drive.

Machine History

This machine was purchased by Stonar School in 1989 and was still in use by Stonar School as late as 1999. In 1991, the machine was upgraded with an ARM3 processor, Simtec 4-8MB RAM upgrade and Oak SCSI controller card with a 100MB SCSI hard disc drive. This configuration remained unchanged until I purchased the machine in October 2013.

Repair/Change History

In October 2013 the machine was fully stripped down and thoroughly cleaned which included the following points.

  • There was minor battery leak damage to the battery holder which was cleaned and the wires were trimmed and re-soldered to the contacts.
  • New batteries were installed to power the CMOS and RTC when powered off.
  • On testing, it became apparent that the real time clock was paused and needed to be reset so that it could keep time when powered off.
  • The SCSI Hard Drive was physically soldered to the LED activity light so it was disconnected and the poor solder work was removed and cleaned.
  • Several connecting wires for the fan, HDD activity light, and battery connection appear the have been damaged in the past and although repairs had been effected, there were unshielded solder connections that could have caused a short circuit. The repairs were re-worked with added heatshrink to insulate the wires.
  • The Oak SCSI card and SCSI drive were removed after recovering all the files from the drive. The drive had begun to exhibit strange behaviour spinning up and down randomly and a verify revealed numerous bad blocks indicating that a total failure was imminent. 
  • IC9 was removed and replaced with an ultra low profile turned pin socket. This allowed for a Retro-Kit Ultra VIDC Enhancer to be fitted.
  • Fitted a Simtec 16-bit IDE card with a 4GB CF card.
  • Flashed the Simtec IDE card with the latest VProtect and AutoVIDC modules so they are both available as soon as the machine is powered on.
  • Fitted an Acorn Econet module
  • Fitted an EtherLAN 500 network card
  • In January 2015, an Acorn AKA32 SCSI podule was fitted.

The Uniboot configuration was installed to allow for easier expansion/configuration and provide support for TCP/IP networking. The Uniboot configuration is identical to my other Archimedes A410/1.

In April 2014, the Watford Electronics 25MHz ARM3 CPU upgrade which was added by the original owner was replaced with an IFEL 36MHz ARM3 CPU upgrade to increase the performance of the machine from @12.72 MIPS to @17.44 MIPS making this by far the most powerful Acorn computer in the Retro-Kit collection.

In December 2014, I fitted an Acorn AKA32 SCSI controller card in preparation for fitting a SCSI hard drive and installing an image of RISCiX on it which I intend to do in early 2015.

Battery replacement schedule

2 Duracell AA alkaline batteries fitted in October 2013.

The next battery change is due in October 2014.

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JASSP Forums

The JASSP project run by Jon Abbott is an attempt to acquire the rights to all of the Acorn Archimedes games back catalogue and archive them for the future.