Strong ARM: The Acorn Archimedes is 25 The Acorn Archimedes is 25 years old this month. The first machines based on the company's ARM (Acorn Risc Machine) processor were announced in June 1987, the year after the 32-bit chip itself was launched. Four versions of the Archimedes were released in 1987: the A305, A310, A410 and A440. The first two had 512KB and 1MB of …
Grey-scale images these days normally range from 0-255, which is usually represented by 8 bits per pixel. I say normally because you can really do whatever you want - like upping the bits per pixel to 16 and having a finer set of intensities, or having 1 bit per pixel for a binary image.
If you had 0 bits per pixel you'd have a blank screen since you couldn't even represent white/black or whatever a 0 and 1 would equate to in your display (green/black?).
I've no idea how it was done in these machines though, I was only a wee lad when I was playing with Lander at primary school and being blown away by it.
Wasn't there a weird doctor who game for it two? Side scrolling platformer with a mad-scientist looking guy in it?
"If you had 0 bits per pixel you'd have a blank screen since you couldn't even represent white/black or whatever a 0 and 1 would equate to in your display (green/black?)."
think original comment was a joke.
Anyway it was a colour display ... after all, to quote the Blues Brothers, it "does both colours, black and white"
Actually the high res mode (which needed a special monitor) was 1152x896, using one bit per pixel. Sometimes it's worth using Wikipedia for fact checking. All the Arabella-based systems could do 1, 2, 4 or 8 bits per pixel. There was also a bash at resolution independence - coordinates were downsampled according to the mode, so in 1152x896 one coordinate step mapped to one pixel, but in mode 12 (640x256, 16-bit) pixels were two coordinates apart horizontally and four coordinates apart vertically (the next pixel above and to the right of 0,0 was 2,4). Mode 13 (320x256, 256 colour) was downsampled by 2 in each direction.
You *could* do 640x512 in 256 colours (mode 21) with a MultiSync monitor, but before the ARM3 turned up with a cache, it didn't leave much bandwidth for the CPU to do anything. Later systems like the A5000 with faster RAM added mode 31 (800x600, 256 colours) etc. And the VIDC20 in the RiscPC added 16- and 32-bit modes and a more programmable video clock.
There are even more rabid fanboys than I in the RISC OS world, so I'll preempt them (or maybe just warm them up) with a few points:
"Risc", as you point out, is an acronym. Thus it should be RISC. Ditto "RiscOS", which should also be two words: RISC OS. "Rom" should be ROM. Confusingly, the last Acorn machine was the RiscPC (in lower case), but the official logotype has a sort of half-space, so most people write is all joined up as I do. Finally, the mouse buttons on an Acorn machine were referred to as Select, Menu and... Adjust, not "Alter".
There seems to be some confusion about the difference between Lander and Zarch: the former was a demo of the latter. The demo (Lander) shipped with most machines in this era, while the game (Zarch) was a commercial full product. It was exactly the same game on the PC, but known as Virus. The player's ship in that was not triangular (it was non-symmetrically pentagonal), and is the same shape as the Copperhead ship from Bell and Braben's game Elite.
Two final points. First: "Archimedes morphed into the Risc PC line, a series of ARM-based boxes designed to run Windows – on a co-processor, and presented in a Risc OS window." No. Just no. The RISC PC was never *designed* to run Windows - it was designed to run RISC OS natively, and use hardware-based emulation to run Windows within RISC OS. The "co-processor" wasn't a true one in the sense you seem to be inferring; the primary CPU was an ARM610, 710 or some variant of the StrongARM processor, while the secondary CPU was a specially designed 4x86 or 5x86 card which could *only* be used by the emulated copy of Windows. It was also not a default item included with the RiscPC, but usually a seperate purchase.
Finally, there's the fact that you say the line stopped with the death of Acorn/Element 14, without mentioning anything about the two spin-off companies RISC OS Ltd or Castle Ltd. Acorn's demise left RISC OS at 4.02, and ROL/CTL developed this further in two confusingly-numbered parallel brances, known as RISC OS 5 and RISC OS 6 (also known under the names RISC OS Select and RISC OS Adjust). There were also the the Iyonix, the Omega, and some other hardware designed and sold in the post-Acorn era. And last but not least, there are ongoing efforts to port RISC OS to small boards like the BeagleBoard and the Raspberry Pi, these mostly happening through RISC OS Open Ltd (ROOL), a spin-off created when Castle decided to open parts of the RISC OS source.
Reg Hardware style (generally) is to present acronyms as they are pronounced. Thus 'Risc' because it is pronounced 'risk' not 'r-i-s-c'. Likewise 'Rom' but 'CPU'.
'ARM' is not 'Arm' because it is a trademark.
And yes, I'm sure you can find inconsistencies if you're nerdy enough to look for them.
Jason: Thank you for picking up most of my ranting! Although I'd point out that Virus was not *exactly* the same as Zarch (and not just because it ran slower). I've clocked Zarch (I still have the disk), but I struggled with Virus on an Amiga.
This has reminded me that my wife made me get rid of my Archimedes (A310, upgraded to 4MB) a couple of years ago. I cried, even though I still have my Spectrum and my RiscPC is still in the family. I may get one from eBay and hide it somewhere, although it obviously won't be the same.
I had a 3010, and still have a RiscPC StrongARM - which still runs!
Christian, Acorns before the RiscPC had to share video memory with program memory, all 0.5 to 4MB of it.
The RiscPC was available with an optional 1 or 2 MB VRAM stick.
Note that those memory amounts are MEGABYTES not GIGABYTES. ISTR paying over 100ukp to upgrade my A3010 to 2MB.
(Mine's the one with a Risc OS Programmer's Reference Manual set in the pocket)
Fantastic machines massively ahead of their time. The 8MHz ARM 2 (not 4MHz as in the article) was about 25x faster than the BBC B, 15x faster than an original PC and 6x faster than a PC AT on Byte benchmarks. It came with built in better than VGA colour graphics, and 4 channel sound, no need for graphics and sound cards before it could do even the most basic things. They could also take 4 (not 2) podule expansion cards including one providing all the digital and analogue I/O we enjoyed on the Beeb.
I remember frequenting a small computer shop which had Atari and Amiga sections. One day they put the new Archimedes on display and my jaw hit the floor when I saw the lander demo. While Zarch eventually appeared on the Amiga & ST (and ZX Spectrum!), at the time it was just incredible to see the raw power on display.
Sadly for Acorn, the power was matched by absurd prices which instantly meant it stood no chance supplanting either the Amiga or ST. It cost over 2x the price of the integrated versions of each of these which meant nobody could afford it. Being Acorn they found sales in the educational sector but I can't help thinking they would have had a lot more success outside of that if the A3000 had been there from the beginning with it's ST520 / A500 style form factor and lower price.
Still I guess someone from Acorn had the last laugh given how ubiquitous ARM processors are these days.
"Sadly for Acorn, the power was matched by absurd prices which instantly meant it stood no chance supplanting either the Amiga or ST. It cost over 2x the price of the integrated versions of each of these which meant nobody could afford it. "
IIRC the schools had a "Must provide kit at half RRP" requirement for suppliers so RRP for kit targetted primarily at the edu sector was price doubled so they did not lose out on the majority of sales.
Of course, this just meant that parents ended up paying double pricing for "edu" targetted kit or ude kit suppliers went bust.
Neat machine, but ultimately beyond my means. A year later I was coding image processing software for a living on an 8 MHz 80286 with 640 MB RAM, and a Matrox PIP1024 image capture and processing board, which had a whole 1MB of RAM. I yearned for the vast 4MB RAM of the A440.
You'd only need a 32-bit CPU to natively address 640MB (actually what you'd need is a CPU with an address bus at least 30 bits wide.)
The 80286 did come with an on-chip MMU , which allowed for logical addressing up to 1GB in protected mode, but sadly it was limited to 16MB of physical RAM (24-bit address bus). You could use additional hardware to provide bank switching (a la Expanded Memory), but I don't personally know of this being used to access up to 640MB of RAM.
Sounds pretty much the same as mine, there was one that only the teacher was allowed to use, but on the one occasion I got to use it (all the others were in use for some reason) the speed was amazing in comparison :)
I don't remember much from the lessons, we were only introduced to them when I was about 6 and the school replaced them with some Windows 98 beasts when I was about 8. All I do remember is that game where you have to transport animals across a river in a boat without them eating each other (I finished first out of the group and got a sticker. Proud.) and being very annoyed at someone in my class who kept adding incorrect spellings to the dictionary rather than correct her mistakes.
El Reg: you're making me feel old!
All misty eyed now, Zarch was great, there was a great feeling of motion about the landscape, especially using trust and letting gravity drop you back down again.
I had a A310, extra RAM, backplane, extra floppy drive, must have cost me close on £1000. Well worth it!
I was writing games in assembler back then for Spectrum, C64, Atari ST. I could render 3D shaded graphics faster in Basic on the Archimedes than I could in assembler on the 8/16bit platforms!
I still have my working A5000 20 years later. I keep changing the hard-disc in it every so often (they seem to last about five years or so), but it runs as well as it ever did.
I ended up with nearly 1GB of storage in it (a couple of near 500MB hard discs). The thing is built like a tank, with very sold metal casing and just seems to keep going. I still have my black and white "hand scanner" (you know the sort, works on rollers) and a pile of software. Probably the best thing was that I ran Windows 3.1 via !PCEm and it capably got me through my college days whilst everyone else seemed to be buying PCs.
ARM Machine were way ahead of anything else at the time, I just think that Acorn sucked at marketing it in the right way.
Have you tried replacing the hard drive with an emulator? There are projects out there that replace the floppy and hard drives of old kit with something that can interface to USB. Probably the best one is the HxC emulator, which definetely supports the Acorn A3000 - http://hxc2001.free.fr/floppy_drive_emulator/support.htm
"Have you tried replacing the hard drive with an emulator? There are projects out there that replace the floppy and hard drives of old kit with something that can interface to USB."
Sounds overly complex to me. An old 1GB CF card and a cheapo 99p CF <-> IDE adapter from eBay, and my RiscPC has both an upgrade and an extension to its life. It's also miraculously silent - I didn't realise that for years, the loud whirring noise wasn't fans or other components, it was my clunky old 800M HDD!
Yes I recall that the very early machines (of which I had one) contained the OS on EPROMs (which have a transparant window in the top, to enable UV erasing) and there were both expensive and re-usable, which is why they wanted them back.
I'm pretty sure that I paid something like £1200 for my A310 (including the Acorn branded monitor) and was somewhat taken aback to arrive home one day and find that the courier had left the boxes piled up on the doorstep (and I wasn't living in a very salubrious area!). Luckily no harm done and I was blown away by the speed and the graphics - there really was nothing comparable at the time for the home user.
I went on to upgrade to the RiscPC before finally turning to the "Dark Side" of a Windows PC late in the 486 era, primarily because it had better games. Still miss the speed of boot and simple "rightness" of the engineering (software and hardware) those old RiscOs machines.
I remember a friend's brother had an Archie, and aside from being completely blown away by Lander (it's reincarnations on ST & Amiga were good, but nothing like as smooth as the Archie version), but most impressively I got to play around with a realtime fractal tool which allowed me to create a fly-by landscape almost the same as the Genesis sequence in Wrath of Khan. On a home PC.
Fantastic machines, but the bit about Lander/Zarch/Virus or whatever else it was called not being possible to implement on Motorola 68k based machines is rubbish. I played Virus on an Atari ST - it was pretty much indistinguishable from the Archie version (and just as hard).
At the sixth form college I went to, the Archie was the only computer they were allowed to buy. This caused annoyance in the music department, since the studio standard at the time was the Atari ST. The department head finally gave up trying to source a MIDI interface for the Archie, and got around the computer purchasing rules by buying a hardware sequencer.
We had an A5000 in our music department at school with a MIDI interface.
We were aware that MIDI interfaces were available, but the problem for my college was getting one as their supplier didn't sell it. As for Sibelius, wasn't that more geared up for producing sheet music rather than sequencing? What the head of the music department wanted was an ST running Steinberg Cubase (or it may have been Pro 24 back in 1989).
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