Andis Acorn Page
about Acorn Computer
Acorn is a small british computer manufacturer who develops and produces computers for the local home- and educational market for quite a long time.
They were well known in the 80s for their BBC-computer, a widely accepted system in England. They produce a 32-Bit RISC processor since 1987, called ARM. This processor was implemented in various flavours and machines ever since, reaching its top in a development by DEC in 1996, the StrongArm, which is being clocked with 233MHz. In 1998 we wait for a new machine to come incorporating some even higher clocked cpu implemented on a pci system, called Phoebe. Unfortunately, it won't come, because after restructuring Acorn the new CEO canceled the whole workstation-division includeing the almost finished new computer model. This is the end of Acorn Computers as computer manufacturer, they now concentrate on marketing their embedded system designs and NCs (Network-computers and Set-Top-Boxes). There may be a chance that a new external company may save the Phoebe or the development of RiscOS. Meanwhile, Intel develops new StrongArm-Designs running at 500MHz to be implemented in PDAs running Windows-CE.
You rarely see these machines away from the island.
The operation system is called RiscOS (currently version 3.7), a cute little thing residing in a 4MB ROM inside the machine and including a GUI, Desktop, mouse, cooperative multitasking, outline fonts, some small applications and lots of little things more.
Because of its easy and well defined GUI, all programs over the last eight years are equally practical and easy-to-use.
Well, it's not as fast as a PC, but it's unspeakable more fun to use and I really hope it will survive the years to come.
some links to visit
You can find a lot of good public domain or shareware programs for Acorn computers in the internet. Instead of giving you lots of entry points here on my page, I rather advise you to have a look at ArcSite which includes a very complete link-list and has a look-up feature as well.
General sites to visit:
- Acorn Computer
- Arche, a german Acorn User-Club.
- GAG, the german Archimedes Group, being the largest Acorn User-Club in germany.
Do-It-Yourself hardware kits
I'm an old hardware freak and like to know what is happening inside my computers. Hence, I'm more interested in small circuits than large programs.
The following projects developed in the past years and involve some hardware and less software.
- A "simple podule" with a lot of IO-functionality:
- up to 512kB Flash-EProm (programmable on-board)
managed in 256*2kB pages.
- a VIA 6522A, running synchronously at 2MHz:
- 2*8Bit Port + Handshake lines,
- 16Bit Timer/Counter + 8Bit Timer,
- 8Bit shifting Register,
- programmable Interrupts (lines + timer)
- an ADC/DAC-Port, 8Bit linear resolution and
useable Samplerates of up to 200kHz.
- Plattform: all Acorn-Computer that have normal Expansion Slots.
- Version: 0.59, 1992-1998.
- State: always unfinished, Software missing.
- Available: not released to public.
- interested people may mail me.
or my friend.
- This was the original ReadMe:
!iicAlarm 1.00 by Andreas Barth, May 1994
A hardware expansion to automatically switch the computer on and off.
!iicAlarm uses the alarm-functions of the standard Archimedes clock-chip
PFC8583, which are currently unused.
It allows setting an alarm-time and switching an alarm-line at that time.
Using a small circuit, this alarmline can be used to switch the computer on.
Under the Desktop, the !Alarm-Application calls the desired programs as
nescessary. At the end of an automatic session, the next alarmtime is set
and the computer switches off via program control. Requires RiscOS 3.
- Plattform: All Archimedes 3xx, 4xx, A3000, others possible.
- Version: 1.00, Mai 1994.
- State: not perfect, but functioning well.
- Available: HERE (app. 85kB).
- ReadMe for autoVIDC-enhancer version 1.00, 24. Feb 1995
This is an instruction on how to build a VIDC-enhancer for older
Archimedes computers A3xx, A4xx and A3000.
All newer models already include the functionality of this enhancement.
The enhancement is switched via Aux1 and/or an external switch.
Instruction is in English only !
- Plattform: All Archimedes 3xx, 4xx, A3000.
- Version: 1.00, Feb. 1995.
- State: finished.
- Available: HERE (app. 22kB).
- A300 Speedup
- This hardware speeds-up the system clock in old Archimedes computers A3xx/4xx/3000 from 8 to 16MHz while all IO-hardware still runs with normal 8MHz clock.
The increase in speed is impressive and allows fluently work even at screen resolutions of up to 800x600x256@56Hz.
The circuit synchronises all access to memory and IO, comparable to the IOMD-chip in the A5000 model, although simpler because the exact doubled frequency is used here.
This circuit only works in especially selected machines which have fast rams (60ns), therefore it never made sense to make it public.
- Plattform: All Archimedes 3xx, 4xx, A3000 with fast memory of 60ns.
- Version: 1.00, März 1996.
- State: finished.
- Available: NO.
- An instruction how to implement a high density floppy disc in older Archimedes Computers A3xx/4xx. This allows to read and write 1.6MB ADFS-F-format discs as well as PC-style 1.44MB DOS-discs.
The tricky thing is to overclock the internal floppy-controller FD1771 for all accesses to high density discs. The problem is that not all normal controller chips like that procedure. And it's very difficult to obtain new controller chips.
This hardware was not developed by me.
- Plattform: All Archimedes 3xx, 4xx, (A3000).
- Version: 1.00, Mai 1997.
- State: finished.
- Available: not yet (app. --kB).
- A 16Bit-sound-hardware for all RiscPC600, (like Mozart or Minni16Bit).
This little circuit is connected to the iis port of the VIDC20 and produces high quality 16Bit sound in stereo. The board includes an additional input to connect the internal CD-Rom to the normal audio system. However, it does not loop-through the old 8Bit Soundsystem.
Some parts may be difficult to obtain.
- Plattform: RiscPC 600 only.
- Version: 1.10, April 1998.
- State: not perfect but working well.
- Available: HERE (app. 55kB).
(last change: Thu.10.12.1998)