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A technical history of Acorn Computers
- amiga386 2y agoAh, the delights of a page that covers 26 years of history and hasn't been updated for 21 years I can at least say that in the meantime, RISC OS is still alive and now open, available from https://www.riscosopen.org/ https://www.riscosopen.org/, and most people will know the ARM company and its architectures went from strength to strength, even if the RISC PC faded away.
- dcminter 2y agoSome time when I have some spare time I must fish out a Pi and try it out - I was deeply envious of the Archimedes owner I knew back in the day!
- xyzzy3000 2y agoI'm not sure what the state of Pi 5 support is, but RISC OS seems to work on the Pi 1, 2, 3 and 4. ArcEm is a decent emulator for the Archimedes series, and RPCem is the equivalent for the RiscPC which succeeded it. OS ROM images are available from a variety of places. For floppy disk emulation, ADFFS is what you are looking for, and some games have been released in this format with the consent of the copyright holders.
- jlarcombe 2y agoDon't think Pi 5 can run 'supervisor code' (in old ARM language) in 32-bit mode, so RISC OS surely won't run. The bulk of it is written in assembler so reworking it to AArch64 would be an epic task. Probably take no longer to rewrite those bits in a higher-level language, for much of it.
- skissane 2y agoDEC had a similar problem when porting VMS from VAX to Alpha - significant chunks of it were written in VAX assembly. They came up with a rather ingenious solution - a compiler from VAX assembly to Alpha. And that was carried forward into the Itanium and now x86-64 ports, so even latest OpenVMS for x86-64 still contains some VAX assembly code, but it is compiled into LLVM IR and then the LLVM backend converts it to x86-64 ELF binaries. No reason in principle why someone could not do the same thing with the 32-bit ARM assembly code in RISC OS. Likely would be easier than rewriting it all in a high-level language
- chasil 2y agoIIRC there was "macro32" which could compile VAX machine code to Alpha, and also VEST, which was a virtual machine. I've used neither.
- skissane 2y agoYes “MACRO-32” [0] is what I’m talking about and is still around - from Alpha it was ported to Itanium and now x86-64. Although to clarify, my understanding is it doesn’t take machine code as input, rather macro assembler source code - although I suppose you could use a disassembler to turn your VAX binary into assembler source and then try compiling it with MACRO-32. VEST wasn’t actually a VM per se, it was a static binary translator - read in an OpenVMS VAX executable, write out an OpenVMS Alpha executable. VEST was only ever available for Alpha, but HP then created AEST which could do the same thing to translate Alpha executables to Itanium-and you could use VEST then AEST in sequence to port a VAX executable to Itanium. However, VSI have said they have no plans to create an “IEST” to port Itanium executables to x86-64. I believe they face two big difficulties: (a) Itanium is a very complex and non-traditional architecture which makes binary translating it more of a challenge than it would be for a more mainstream architecture (b) legal risk due to aspects of it being covered by Intel patents (and unclear if Intel would license those patents on terms which would make an “IEST” commercially viable) [0] https://en.m.wikipedia.org/wiki/VAX_MACRO https://en.m.wikipedia.org/wiki/VAX_MACRO
- sillywalk 2y agoTandem used something similar called The Accelerator to translate binaries from their proprietary CISC chips to MIPS, including parts of the NonStop operating system. See Tandem Systems Review, Volume 8 Number 1 - Spring 1992
- lproven 2y ago> Don't think Pi 5 can run 'supervisor code' (in old ARM language) in 32-bit mode, so RISC OS surely won't run. The RISC OS folks are well aware of the issue. There are discussions about what to do underway. One idea that I sort of like is a tiny sort of hypervisor in Arm64 code, that runs an Arm32 "VM". Then RISC OS executes in the VM. It's not fully native, no, but with the speeds involved, it would be usable. There is a lot of prior art for this approach: 1. RISC OS already faced a 24-bit to 32-bit migration, and one bit of the legacy of that is an emulator for running 24-bit RISC OS apps on 32-bit RISC OS, called Aemulor. https://en.wikipedia.org/wiki/Aemulor https://en.wikipedia.org/wiki/Aemulor 2. There is of course a whole industry running x86 PC emulators on x86 PCs. The one that started it is called VMware and it did quite well. But others copied it: e.g. Connectix ported VirtualPC from Classic PowerPC MacOS to Windows. I interviewed the company's founder and chief scientist Jonathan Garber. https://en.wikipedia.org/wiki/Webcam#Early_development_(early_1990s) https://en.wikipedia.org/wiki/Webcam#Early_development_(earl... At that time, x86 didn't do hardware virtualisation. So, VMware just used a software emulation for ring 0 code. Garber told me that once he saw how VMware did it, he realised Connectix could do that, too. He then told that it was much easier than running x86 code on PowerPC. With a grin he said that it was not only easier, the performance was excellent: the instruction sets were a _really_ close match. ;-) So the emulator was very nearly achieving 1:1 code density: one instruction for one emulated operation. 3. When Apple moved Classic MacOS from 680x0 to PowerPC, it did it using a tiny "nanokernel" containing a 68K-to-POWER ISA emulator. https://en.wikipedia.org/wiki/Mac_OS_nanokernel https://en.wikipedia.org/wiki/Mac_OS_nanokernel
- jlarcombe 2y agoyes, surely a good approach, and as you say the performance is likely to be fine given the vast increase in raw speed since the old days...
- sammyteee 2y agoA good read! I like that all the sites linked in the banner, no longer exist! https://www.mcmordie.co.uk/public/apeople.shtml https://www.mcmordie.co.uk/public/apeople.shtml
- xyzzy3000 2y agoI particularly liked the tiling background, which may well have been created using Texture Garden https://texturegarden.com/ https://texturegarden.com/ by Tim Tyler (of Repton fame, for the BBC Micro fans)
- II2II 2y agoThere are plenty of links on other pages that lead to functional websites of various vintages (the keyword being vintage). Just go to https://www.mcmordie.co.uk/ https://www.mcmordie.co.uk/ and start exploring.
- dcminter 2y agoSomeone will be along in a minute to tell you to watch Micro Men, an amusing and fairly accurate BBC dramatization of the Sinclair/Acorn rivalry :) but I'm here to recommend that you watch the Computer History Museum's interview with Hermann Hauser the erstwhile director of Acorn - he's very charming: https://m.youtube.com/watch?v=Y0sC3lT313Q https://m.youtube.com/watch?v=Y0sC3lT313Q I'm fairly sure they've got one with Chris Curry too, but I can't spot it just now.
- amiga386 2y agoIt would appear you can watch Chris Curry and Hermann Hauser watch Micro Men: https://www.youtube.com/watch?v=yaonVYOTSsk https://www.youtube.com/watch?v=yaonVYOTSsk -- and then have a post-viewing chat: https://www.youtube.com/watch?v=l4I2ktcWdJM https://www.youtube.com/watch?v=l4I2ktcWdJM "I saw the first five minutes and had to run away, because I couldn't bear to see myself portrayed by Martin Freeman" -- Chris Curry
- timthorn 2y agoWhich was hosted by the Centre for Computing History!
- xyzzy3000 2y agoIt's an entertaining watch, although a fair bit of dramatic licence is taken when depicting various anecdotes that would be well-known to readers of The Micro User and similar magazines of the time.
- eurekabot123 2y ago[dead]
- westi 2y agoSome great memories here. Somewhere in my parents attic is my RISC PC 600 and 486 Co-Processor card. Not sure if they also have the A3000 we had before that.
- xyzzy3000 2y agoIf possible, get the batteries removed from the motherboards - the leaks cause immense damage. Rechargeable AA batteries in a battery holder are a sensible replacement. If the hard drive has packed in then a SD to IDE/PATA adapter is available.
- simonjgreen 2y agoMy secondary school was full of these in the computer labs. Great bits of kit :) The dual boot between architectures blew my mind at the time, and frankly is still pretty extraordinary. And unlike most boxes of the time, they even looked good!
- xyzzy3000 2y agoSchool lab RiscPCs tended not to look as good as this one though - the 'Rocketship RiscPC' with integrated pizza oven and kitchen sink: https://web.archive.org/web/20050305122925/http://www.d1.dion.ne.jp/~r_high/memorial/rocketship.html https://web.archive.org/web/20050305122925/http://www.d1.dio... https://web.archive.org/web/20050207161844/http://www.worldofwibble.com/aboutriscpc.html https://web.archive.org/web/20050207161844/http://www.worldo...
- callumprentice 2y agoI purchased an Acorn Atom in 1980 (the prebuilt one - a friend opted for the self-assembly and regretted it) and I still remember the thrill of setting it up and turning it on for the first time. It feels like I didn't sleep for a week but I suppose I must have. When you entered a line of their BASIC, it would check the line for errors. At one point, I kept getting error XX (I don't recall the actual number) and couldn't see the error in my code. Eventually figured out it meant I was out of RAM. There was only 2K and I think the 6502 took some and the screen too so there was only about 500 bytes left over. What a joy it was after I saved up for the 6K upgrade. And then there was the local computer club presentation that ruined any chance of a public speaking career.... :)
- andrehacker 2y agoO man, good times. I remember soldering RAM chips "piggyback" style, then upgrading to 64K of RAM, and adding 8 special-purpose ROMs (from utilities to a spreadsheet program). I even installed a color video board— all of this inside the Acorn Atom itself (which was a keyboard-style computer, similar to the C64). The Atom also brought together a community of hardware and software enthusiasts through Atom Computer Clubs. These clubs were doing amazing things, including the development of Z80 co-processors and even running CP/M. While Acorn moved on from the Atom to the BBC Microcomputer, the clubs kept the Atom alive well beyond its prime. It’s fascinating to look back and realize that the same team behind the Atom went on to create the ARM processor, which, interestingly, shares a striking similarity in its instruction set with the 6502.
- callumprentice 2y agoGood grief - 64K - what on earth did you do with all that storage :)
- chasil 2y agoDo you have more details on the striking silarity? All the wiki mentions is optimized memory usage.
- 2y ago
- jefc1111 2y agoFor me, all this ... computer life stuff ... started with an Acorn Electron around 40 years ago. At first it was just fun, and then I played Elite and it feels like a lot of my future was defined in that experience.
- simonjgreen 2y agoDitto. Electron and Elite with a voltmace joystick that (memory may be hazy) had like 20 buttons on it was mind blowing to child me.
- aardvark179 2y agoThat’s how I started as well. Much nicer to program than the spectrum, and taught me about parsing in the worst way when I discovered my text adventure couldn’t have a variable called torch because it was. Parsed as to rch.
- LoganDark 2y ago> and taught me about parsing in the worst way when I discovered my text adventure couldn’t have a variable called torch because it was. Parsed as to rch. "to rch" reminds me of the "x goes to 0" meme: https://stackoverflow.com/questions/1642028/what-is-the-operator-in-c-c https://stackoverflow.com/questions/1642028/what-is-the-oper...
- tolien 2y agoSame, and now I'm still playing Elite but just with slightly better graphics :-D
- tonyedgecombe 2y agoMy first computer was an Acorn System One. I spent a summer picking fruit at an orchard to pay for it. 1k of RAM, 512 bytes of ROM, a seven segment calculator display and hex keyboard. I spent hours hand assembling 6502 code for it. I even created a stack based language for it in an attempt to teach my younger brother how to program.
- xyzzy3000 2y agoFor anyone interested in the very early Acorn era, there are some replica boards available here, from System 1 all the way up to System 5: https://theoddys.com/acorn/replica_boards/replica_boards.html https://theoddys.com/acorn/replica_boards/replica_boards.htm...
- Lio 2y agoSo much history here for me. One landmark buried in there was the ARM 250 chip based machines. I think they were some of the first system on a chip desktop computers. They lacked the glamour of the Arm 3 based machines launched around the same time but really they were ground breaking.
- xyzzy3000 2y agoI think it was possibly the first to go into a desktop computer. ARM250 datasheet here: https://home.marutan.net/arcemdocs/ARM250.pdf https://home.marutan.net/arcemdocs/ARM250.pdf For Acorn, this chip really helped to bring costs down for the A30x0/A4000 machines - the Electron of the Archimedes era. The RiscPC equivalent was the A7000/A7000+ with the ARM7500/ARM7500FE, the FE being novel for the inclusion of the FPU which ARMs had traditionally not included.
- Lio 2y agoThe A7000s sort of passed me by as I had a RiscPC at the time (which predicatably I really regret selling). I always wanted an FPU for my RiscPC, do you know how much difference they made day to day?
- xyzzy3000 2y agoThe ARM7500FE is considerably slower (in terms of clock speed) than a StrongARM, but the FPU apparently makes StarFighter 3000 run very well. StrongARM with an FPU would have been incredible, however no FPU option exists for the RiscPC. There was a commercial software package that would allow the FP capabilities of the 486/586 copro to be used from RISC OS, but I'm not sure how effective it was.
- draazon 2y agoIf the page author is reading this: hello Rob!
- simonjgreen 2y agoA nice note of recognition of the contribution of the Acorn made BBC Micro model A and B to millions is that the Raspberry Pi Model A and B were named in honour of them.
- xyzzy3000 2y agoI suspect that the Pi 400 kit is a nod to the Archimedes 400 series, but I haven't seen anything to confirm this.
- lproven 2y agoHuh. Interesting but I think it's coincidence TBH. The all-in-one Archimedes were the 3xxx series: A3000, 3010, 3020. https://chrisacorns.computinghistory.org.uk/Computers/A3000.html https://chrisacorns.computinghistory.org.uk/Computers/A3000.... https://chrisacorns.computinghistory.org.uk/Computers/A3010.html https://chrisacorns.computinghistory.org.uk/Computers/A3010.... https://chrisacorns.computinghistory.org.uk/Computers/A3020.html https://chrisacorns.computinghistory.org.uk/Computers/A3020.... That would have been a far more obvious and better fit. The Pi 400 is based on the Pi 4, so 4000 would have fit, but the A4000 was a classic 3-box design with a SoC: https://chrisacorns.computinghistory.org.uk/Computers/A4000.html https://chrisacorns.computinghistory.org.uk/Computers/A4000....
- whywhywhywhy 2y agoMight be a nod to Amiga 500 which was far more prolific outside of schools in the UK and was keyboard form factor.
- geye1234 2y agoA wonderful snapshot of the 90s web. The entirely unaffected tone, the lack of self-consciousness, the random content, the humor, the joke lists, everything. We've lost a lot. The marginalia search engine is very good at finding this kind of site, btw.
- junto 2y agoMy first computer was an Acorn BBC B Microcomputer. This brings back very fond memories of playing Repton and Elite and having to wait for the tape cassette to load the games.
- xyzzy3000 2y agoBoth Ian Bell (Elite) and Tim Tyler (Repton) have fascinating websites of their own. Elite is there for download alongside a treasure trove of historical information, and Tim has a successor to Repton, 'Rockz', which expands on a lot of the concepts in interesting ways. https://timtyler.org/ https://timtyler.org/ http://www.iancgbell.clara.net/index.htm http://www.iancgbell.clara.net/index.htm
- owlbite 2y agoOur first family computer was an A3000. I'm still amazed at the boot time on it compared to the PCs we had later (even today). Switch it on, beep and then almost instantly you're in a responsive GUI. (The wonders of storing the OS in a ROM I guess).
- johnflan 2y agoI started with an Acorn a3020, those machines were just amazing. I got my first PC shortly after running Windows for workgroups 3.11 jeez it felt like a step backwards. If Acorn started in the Silicon Valley, we'd probably be using them today.
- Lio 2y agoOne small error I've noticed on the Phoebe page, the man who killed Acorn was a guy called Stan Boland not Sam Boland. I leave someone with better knowledge to tell that one but it's a pretty sad story.
- panick21_ 2y agoGreat talk about the Archimedes: https://www.youtube.com/watch?v=Hf67JYkUCHQ https://www.youtube.com/watch?v=Hf67JYkUCHQ Really a neat design.