RISC OS 3.10/3.11

For first generation 32bit computers



RISC OS 3.10 is included with the following products.

Classic RISC OS ROMS for Emulators

The Classic ROMS collection brings together a fully licenced collection of ROMS for both Arthur and RISC OS. The collection covers the entire range of 32 bit ARM (Acorn Risc Machine) computers developed by Acorn Computers Ltd from the A310 to the StrongARM RiscPC. Every ROM comes with Boot Sequence, Apps, Utilities and instructions for a range of emulators...

Available for immediate download - 10.00




RISC OS 3.11 requires 512KB (1MB recomended) of RAM and a floppy disc drive. Hard discs are supported but are optional.

The following computers could be upgraded from RISC OS 2 to RISC OS 3.10 or 3.11.

  • Acorn Archimedes A305 with 512KB of RAM (adapter board needed to support 4 ROM chips)
  • Acorn Archimedes A310 with 1MB of RAM (adapter board needed to support 4 ROM chips)
  • Acorn Archimedes A440 with 4MB of RAM and ST506 hard drive
  • Acorn A410/1, A420/1 and A440/1 (harddisc optional)
  • Acorn R140 (RISC OS can be installed instead of Unix)
  • Acorn A3000
  • Acorn A540
  • Acorn R225/R260 (RISC OS can be installed instead of Unix)

The following computers could be upgraded from RISC OS 3.00 to RISC OS 3.10 or 3.11.

  • Acorn A5000 original release

The following machines were supplied with RISC OS 3.10 and later RISC OS 3.11 on 4 ROM chips.

  • Acorn A5000

The following machines were supplied with RISC OS 3.11 on 2 ROM chips.

  • Acorn A3010 with 1MB of RAM
  • Acorn A3020 with 2MB of RAM
  • Acorn A4000 with 4MB of RAM
  • Acorn A4 - laptop with greyscale LCD screen



The following support documents relate to this version of RISC OS:

Further support documents for RISC OS users can be found here.
Further support documents for RISC OS developers can be found here.



To replace the now aging A400/1 models Acorn had prepared a new design, the A5000, based around the ARM 3 processor. The ARM 3 had first been used in the A540, but the A540 was a very expensive machine to make and cost thousands to buy. ARM 3 processor upgrades for the A310, A440 and A420/1 were now available from several suppliers and provided a huge performance boost for ARM 2 machines.

In order to reduce the production cost Acorn decided that the new machine would replace both the A400/1 series and the A540. To go with this new machine Acorn needed a greatly improved operating system, RISC OS 3. This incorporated a large number of improvements, many of which were inspired by (or based upon) the various add-ons and fixes available through the booming PD scene.

important advances were made to accommodate the new hardware. There was built in support for the ARM 3 processor and, as the A5000 was to use the newer high density floppy disc drives, support and drivers for those as well as the older double density drives. It was now possible to read and write to 720K and (hardware permitting) 1.44MB DOS formatted discs which made data exchange with PCs much simpler. The A5000 was the first Acorn computer to use an IDE hard drive and so the ADFS filing system was updated to work with these and the appropriate drivers for the on-board IDE drive controller included.

As happened so often in Acorn's history the hardware was ready before the operating system was really completed. The first A5000s therefore shipped with RISC OS 3.00. RISC OS 3.00 looked great and the advances over RISC OS 2 were both plentiful and obvious. However something else was also plentiful and obvious, bugs. RISC OS 3.00 had suffered badly from rushed development and as a result it wasn't long before Acorn were inundated with complaints from both users and dealers.

Acorn engineers started dealing with the problems that were reported and, a few months later, Acorn announced the improved RISC OS 3.10. This was intended as a replacement for RISC OS 3.00 in the A5000 and also as an upgrade for the earlier models. The upgrade pack for the A5000 contained just the four ROM chips, a couple of floppy discs and a single sheet of instructions and cost around £25. The upgrade pack for the A400, A540 and A3000 models had more comprehensive instructions, a printed RISC OS 3 User Guide and Applications Guide and the same set of ROMs and floppy disc contents and cost more than £50. It didn't take users long to realise the disparity and within a few months Acorn discovered they'd sold far more A5000 RISC OS 3.10 upgrade packs than they had A5000s.

There had been a problem with the serial port on the A5000 and so a replacement serial module was incorporated into the next batch of ROMs as RISC OS 3.11 and this is still the final officially released version. Acorn also released the module as a stand alone component that could be loaded on machines running RISC OS 3.10 if required.

Because RISC OS 3.1 was intended to be used not only in the A5000 but also in all the other Archimedes machines, that is, the A300, A400, A400/1, A540 and A3000, it also included all the necessary code to support these models. This is really only outwardly visible in the !Configure option for hard drive. Here you can configure not only the number of IDE drives as used on the A5000 (and later on the A3020 and A4000) but also ST506 drives as used on the A400 and SCSI drives as used with the Acorn SCSI interface on the A540.

For the A400, A540 and A3000 models the upgrade merely required the fitting of the new ROMs and changing a couple of links on the motherboard. However with the A300 (and also the original Series 1 A440) it was necessary to fit a daughter board to accommodate the new ROMs as the original sockets on these models were only large enough to hold the 256MB chips used for Arthur and RISC OS 2 whereas the new ROMs were 512MB.

Acorn's replacement for the A3000, the A3010 and its companion models the A3020 and A4000 which used the new ARM250 processor also used RISC OS 3.11. The only difference with these models was that it was incorporated into two 1MB instead of four 512MB ROMs.


© Copyright 3QD Developments - 28/10/2015