View Full Version : Any Acorn Archimedes people here?

May 21st, 2015, 01:39 AM
I have recently bought an Acorn Archimedes A3010, and am just learning about the machine and the OS.
Eventually the goal will be to write some graphics/music routines and do a demo or perhaps even a game.
The machine intrigues me somewhat because of a few reasons:
- It seems to have been quite popular in the UK, but barely known outside it (I'm not in the UK, so this is only the second Archimedes and the third Acorn machine I've ever seen)
- It was the first computer to use the ARM CPU, which is now one of the most widespread architectures in the world
- The CPU is massively powerful compared to its peers
- Not a whole lot of games and demos have been developed to really show off what this machine can do

I hope one day to make some 'Amiga-killer' routines, in the same way as 8088 MPH was somewhat of a 'C64 killer' demo: use the raw CPU/memory power and clever trickery to compensate for the lack of audio/video capabilities in the chipset.

Anyway, for now I'm just learning the basics of the computer, and figuring out how to transfer software between the A3010 and my PC.
I'm also using RPCemu on the PC for a somewhat easier environment to play around in.

So I was wondering if there were some other Acorn users out there, and if they perhaps had some nice tips to get me started, or interesting stories about their computers etc.

May 21st, 2015, 11:20 PM
I myself have a A3010; but I've never messed up too much with the computer :-(. In fact, it badly needs a good check as the battery hasn't been replaced since a long time.

If I'm not wrong, the machine (apart from being really cool) can read PC formatted disks; so transferring software can't be too difficult.

May 22nd, 2015, 12:01 AM
I own an A4000. I put an "ready-to-use" image on the HD with a normal PC and put it back in the A4000.
The image is full of software...but currently I am working on other things, so I can't tell you much about
the system.


Some stuff: https://www.youtube.com/user/Archimedes75009/videos

May 22nd, 2015, 05:50 AM
I've got an A3020 and a dead StrongARM RiscPC (burned out the VIDC20 because it turned out I was overclocking it with insufficient cooling, when I thought I was staying in safe limits).

There's essentially three generations of the Acorn hardware.

First generation uses the ARM2 (or ARM3)/IOC1/VIDC1a/MEMC1 (or MEMC1a) chipset, with a WD1772 floppy controller driving an 800 KiB DSDD 3.5" floppy drive (which can use 720 KiB DOS floppies). This consists of the A3xx (entry-level desktop, 512 KiB-1 MiB RAM), A4xx (originally high-end desktop, 1 MiB-4 MiB RAM and an available ST506 hard drive), A4xx/1 (A4xx with MEMC1a), R140 (A440/1 with Unix), A540 (high-end ARM3 desktop above the A440/1, 4 MiB-16 MiB RAM, SCSI hard drive), R2xx (A540 with Unix), and A3000 (basically an A305 with a MEMC1a in an Amiga 500-style case). All of these machines except the A540 and R2xx are 8 MHz ARM2 (with an 8 MHz memory bus), the A540 and R2xx are 26 MHz ARM3 with a 12 MHz memory bus (but all of them can be upgraded to 33 MHz ARM3 in various ways).

Second generation is basically the first generation, but with a cheap ISA Super I/O chip handling things like the floppy drive (now 1600 KiB DSHD, and able to use 1440 KiB DOS floppies in addition to all the DSDD formats), serial, and parallel ports. A3010 (1-2 MiB gaming-oriented machine to replace the A3000, with either a mezzanine board with a 12 MHz ARM2 and the rest of the chipset, or a 12 MHz ARM250 SoC), A3020 (2-4 MiB school-oriented version of the ARM250-based A3010 with a network port and (horrible) PATA HDD support, but no joystick port), A4000 (A3020 in a desktop case, basically), A5000 (4-8 MiB 25-33 MHz ARM3 desktop), and A4 (24 MHz ARM3 laptop). All of these machines have 12 MHz memory bus. The A3010 with mezzanine board can be upgraded to ARM3, the ARM250 machines can't be.

Third generation (often referred to as "IOMD") keeps the cheap Super I/O chip, but upgrades the chipset to ARM6 (or ARM7 or StrongARM)/IOMD1/VIDC20. This was a much bigger change than the second generation, and was used in the RiscPC (various CPUs from a 30 MHz ARM6 to a 233 MHz StrongARM from Acorn, and up to a 300 MHz StrongARM with local 66 MHz SDRAM from Castle, 16 MHz CPU memory bus with dedicated VRAM for the VIDC20), A7000 (I think it's a 16 MHz CPU memory bus, 32 MHz ARM7500 SoC (ARM7/IOMD1/VIDC20 on a single chip)), A7000+ (48 MHz ARM7500FE), and A7000+ Odyssey (56 MHz ARM7500FE, and I believe the memory bus is faster).

After that, there's some clones of the A7000 series, a couple ultra-rare and ultra-buggy clones of the RiscPC, and then some new hardware that the OS has been ported to.

As far as the OS version, for your A3010, run RISC OS 3.11, and call it a day. (That really applies to any first or second-gen hardware.)

Because you're running RPCEmu, though, IOMD discussion is also relevant. For an IOMD machine, there's a few options. First to consider is what ROM to run. 3.71 is the final Acorn release, 4.02 is the baseline post-Acorn release (but it's essentially just Acorn's own RISC OS 3.80 betas that were going to be released as 4.00, before Acorn effectively shut down, finished and released) that developers expect as a bare minimum, and then newer stuff gets fragmented from there. I'd personally run a 4.02 ROM (no newer (compatibility issues), no older (functionality loss)) in Acorn IOMD hardware (or the appropriate "4.03" or "4.04" release for your clone IOMD hardware), but there are reasons to run 3.71 (maximum compatibility with Acorn-era software). For targeting a demo to run on the most IOMD hardware, though, I'd lean towards 3.60-4.39 compatibility, or at least 3.71-4.39 compatibility. (3.50 is something that most machines don't have any more AFAIK.)

Once you've picked your physical ROM, from 3.60-3.71, you can softload a 4.02 ROM (if you're keeping an old ROM in the machine for compatibility reasons, at least you can run software that requires 4.02 by softloading it), but you don't get 4.02's long filename support, and you can't softload most newer stuff. From 4.02, you can softload anything newer and not lose anything. Softloading 4.39 isn't a bad idea to get DHCP, and it avoids most of the weirdness that RISCOS Ltd started putting in later. The other option is to go with RISC OS Open's IOMD builds of 5.xx (which forked from 4.02, and have basically all of the 4.39 functionality that people care about, and now some newer stuff), but they're 32-bit builds, not 26-bit, which means you can only run newer software that's been modified to be 32-bit clean, so I'd advise against it. And, if you're gonna run 5.xx, really, just buy a Raspberry Pi and run it on that. (The exception is if you're emulating in RPCEmu, but 5.xx is a bit buggy in that, so really, just buy a Raspberry Pi if you want to run 5.xx, period.)

Mind you, in an emulator, softloading doesn't make sense, just boot the ROM you want, and it's not that bad to switch.

Also, consider running Arculator or ArcEm, they're emulating the actual first/second-gen hardware instead of the IOMD hardware.

May 22nd, 2015, 11:59 AM
I've got a few Acorn systems in various states of repair- A3000, 410/1 with cpu and ram upgrade, a dead A5000, a couple of A4000s a number of RiscPCs with/without Strong Arm processors, as well as some spares and software. There'll be some useful links, a few are no longer useful, in my Acorn thread- http://www.vintage-computer.com/vcforum/showthread.php?23526-What-have-I-done

For rolled up ready to run Risc OS 3.1x "distros" go to this site http://qubeserver.com/Qube/classicriscos.html

Lawrence Woodman
May 22nd, 2015, 10:28 PM
The Archimedes' were fantastic machines. I remember my mother bringing home an a3020 from school and thinking how fast it was and how smooth it ran. I liked that fact that it booted up instantly and everything seemed to be really well integrated. This was in about 1993 so I would have been comparing it to my 80386 running DOS and Windows 3.1.

I have recently become interested in getting one and am at the moment enjoying playing around with arcem until I have the space to set up a real machine.

Have fun


May 23rd, 2015, 10:48 AM
Do the RISCOS machines have any value? I have recently scrapped some test gear based on the Acorn RISCOS PCBs. At the moment they are hovering over the gold recycling bin. They had an IDE disc, floppy and a number of video and network boards. Rather sell than scrap them.

May 23rd, 2015, 11:00 AM
To the right person most probably as a source of spare parts. Better off to asking at this forum http://www.stairwaytohell.com/ as there will be more collectors with these types of systems.

May 23rd, 2015, 11:23 AM
Remarkable machine--the first versions of the Sibelius music transcription software were done on those systems. Sadly, the Acorn is no longer supported, but Sibelius is still very much around.

ISTR that a NS 32016 card was available for the Acorn, which makes it doubly interesting.

May 23rd, 2015, 12:12 PM
Indeed, but like any system they're not perfect by any stretch of the imagination. Acorn made some stupid hardware design decisions like most manufactures. But that all by the by. Having the OS in rom is useful and is speedy. Loading up from the hdd levels things out a bit when comparing them to other system types, as far as getting to the desktop goes, as there are configuration files to wade though.

For example loading my A4000 to its desktop takes about the same amount of time as loading GeoWorks on top of Dos to it's Motif desktop on my Zenith 286/12. My 386DX25 with wfw 3.11 takes a bit longer but it is fetching a tcpip address in the process. The GUI is a co-opperative mutitasking setup, even still on the RPi, just like Classic Mac OS, Win/WfW 3.x and PCGeos. Of course the desktop is just one aspect. It has the option to boot to cli or basic as well. Obviously these is a purely subjective comparisons under the hood they're a stunning bit of kit. Acorn systems do suffer from what I guess can be described as dependency issues similar to any other OSs/GUIs.

May 23rd, 2015, 01:36 PM
The 32016 was for the BBC Micro line, and was one of the things they were evaluating as a replacement for the 6502. The BBC Micro had an interesting architecture regarding second processors (and they even sold 6502 second processors that ran faster and had local RAM, and ran the same BBC Micro software making the OS calls into the host 6502 - this approach was (for BASIC code, anyway, which didn't need to be ported) used as-is on the ARM second processors).

As I understand it, they were looking at the following chips:

32016 (too slow interrupt response - DIV can be something like 138 cycles)
68000 (even slower interrupt response - DIVS can be 174 cycles, I believe)
80286 (Intel wouldn't license it to them to modify for their own use)
65816 (not actually for the true successor to the BBC Micro/Master line, for another product, but when they saw how small Western Design Center was, they realized they could just do their own CPU)

The interrupt response problem wasn't a problem in the BBC Micro, where the host 6502 was handling I/O, but Acorn wanted to be able to respond to interrupts fast enough to service a double density disk, and the 32016 and 68000 couldn't do it. There was always Apple's approach of shutting off interrupts and racing the head (which worked to let the 68000 do even high density on the Mac), but that's a pain and held the Apple II at 1 MHz for the longest time (and is part of why a IIGS has to slow to 1 MHz quite often).

Acorn also made and sold a 80186 second processor running DOS Plus, as part of evaluation of x86 for the possible 80286 project, and the first ARMs were on BBC Micro second processors.

It's also worth noting that RISC OS basically began as a port of Acorn MOS to the ARM. (This has interesting implications, because the whole Tube second processor architecture was supported too, and Acorn actually used it with !65Tube, which could run BBC Micro 6502 software in emulation, but making OS calls into the native ARM OS, and taking advantage of Archimedes hardware, the same way that they would run on a 6502 second processor on a BBC Micro.)

May 27th, 2015, 12:07 AM
Cool, thanks for the info so far guys!
Sadly, when I hooked up my machine again over the weekend, it did not power up correctly anymore.
I think the PSU may have some bad caps.
Shame, that dampened my motivation somewhat. I still only have the emulators to work with.
I hope I can get it repaired.

I have found some interesting tools however...
For example, apparently it is possible to read/write physical Acorn floppies with a PC: http://knowbody.org.uk/arcimage/
Yes, newer Acorns can read MS-DOS floppies, but as I have found, that only has limited use, since RiscOS has all sorts of extra metadata that doesn't work on MS-DOS floppies.

Also, I have found some C/C++ compilers and documentation here:

Although, from what I understood, the built-in BASIC is actually quite powerful as well, and supports inline assembly. I was told that even games like Elite were written in BASIC+asm, rather than using the C/C++ suite with asm (which is something I would have expected for a 'modern' system like this).

May 27th, 2015, 02:16 AM
The metadata that actually matters is a 12 bit filetype per file, it's worth noting. Also, don't extract zip files of RISC OS software on a non-RISC OS system, or you'll lose that metadata.

One annoyance specific to the A3010/A3020 hardware is that the power supply is on the motherboard. Everything else has it fairly separate and not doing anything weird (so in a pinch you could adapt an AT power supply or similar to the right connectors), but not those two models.

May 27th, 2015, 02:40 AM
I was told that an archimedes can handle ADF images on Harddisk that were copied using a fat-formated medium (eg- zipdrive)
with a tool named "!ADFFS" or so. I could not test this, because I do not have ADF-Files for an Acorn Archimedes.


May 27th, 2015, 10:57 AM
As bhtooefr mentions its easy enough to extract compressed files in an Acorn Risc machine on Fat12 floppies using freely available tools loaded into ram. I've transfered uniboot to hdd that way. Uncompress the /zip file to ram drive then copy the extracted files to the hdd. Simple.

Lawrence Woodman
May 27th, 2015, 11:30 PM
I was told that an archimedes can handle ADF images on Harddisk that were copied using a fat-formated medium (eg- zipdrive)
with a tool named "!ADFFS" or so. I could not test this, because I do not have ADF-Files for an Acorn Archimedes.

If you want to give it a try here is Elite for the Archimedes (http://www.elitehomepage.org/archive/a/b5052420.zip) as an ADF image from Ian Bell's Elite files (http://www.elitehomepage.org/archive/index.htm) page. If you haven't come across it already here is the !ADFFS (http://adffs.filecore.net/) page.


May 28th, 2015, 06:10 AM
Sadly, when I hooked up my machine again over the weekend, it did not power up correctly anymore.
I think the PSU may have some bad caps.

Check also for battery leaks, they can be extremely severe in this machine.

June 23rd, 2015, 03:47 AM
Check also for battery leaks, they can be extremely severe in this machine.
Acorn 32 bit machines suffer from the Ni-Cad RTC backup battery (for the combined RTC & CMOS SRAM chip) leaking or going flat :(.
The battery going flat looses configuration information. Then the OS gets confused. You have to reset the CMOS SRAM and re-enter configuration settings.
The battery leaking is more serious, as the "acid" damages components and PCB tracks/traces :evil:.

Lots more information (including how to reset the CMOS SRAM and re-enter configuration settings and how to clean up and repair battery damage) and help on this UK based forum: http://stardot.org.uk/forums/ :D