I was the sales manager and then later the technical services manager of Orion Computers who were a decent sized Acorn dealer. We produced our own products and were a service centre with me being a component level service engineer. The 300, 400 and 400/1 were the predecessors with the 540 and unix boxes coming out just afterwards. The price was about the same as a bbc micro taking inflation into account. I was responsible for the A3000 podule expander :-) and we also did 1 and 4mb upgraded with the 4Mb replacing the 1Mb because the MEMC could only address 4Mb. The 540 had a MEMC for each 4Mb board with 16Mb max. The Econet module was the same :-) RiscOS was a really good OS. I loved the way the folder auto ran and all the setup files etc hide inside it and with relative addressing you could just move them about. I loved the Archimedes machines. I remember build several Econet networks but we had thin wire Ethernet at the shop/workshop.
I answered before finishing watching! We did get 8Mb on an A3000 but it was too expensive and like the Arm3 required socketing of surface mount chips! The 400/1 etc had socketed MEMC, IOS, ARM and VIDC so it was a bit easier :-)
The correct answer to Atari ST or Amiga is: Acorn Archimedes. Deeply underrated, under appreciated computer that deserved better than being another educational system.
It had its revenge even if it was served cold. Its ARM architecture is everywhere in mobile devices now, whereas Amiga and Atari ST are niche enthusiasts’ tinker toys
@@little_fluffy_clouds True, although ARM's days seem to be numbered with the rapid uptake of RISC-V. It's amazing how fast RV has gone from zero to where it is now.
I don't think RISC-V is an existential threat to Arm, just a financial one. Arm went from having effectively no competition to having to compete with RISC-V vendors in some market segments.
The A3000 was sold under the Archimedes name in Germany, without using Acorn‘s name. I remember ads for the „Archimedes A3000“ in German Amiga and Atari magazines.
It was the same in Sweden. I was an Amiga fan but was still close to buying this. Even got an ARM assembler book to start learning. It looked so cool but unfortunately I never got one. Would have been cool to have today :)
I had an A3000 in the early 90s. Loved it. I was still rockin' the ZX Speccy +2 and got an Amiga a few years later, and PC with an Aztech "Quad Speed" CD drive. lol But I would still fire up the A3000 very often. The built-in BBC BASIC was great fun to mess with. Dad bought the RISC OS 3.1 ROMs around 1994. I had a Philips CM8833-ii as my main monitor through most of the 90s. I used the monitor to watch TV and movies on, recording stuff off TV on a Sanyo Betamax VCR. (things like Red Dwarf, Reboot!, X-Files, Games Master, and Bad Influence.) Always had it all hooked up to a Rotel amp and speakers. lol I still have four magazine floppy disks for the A3000. It's pretty much the only thing I have from that time. One of the disks had a demo of Quark (shoot-em-up) on it.
On Halloween, I would often play No Excuses and Rotor, etc. From the "Play It Again Sam" games pack. Great times. Seeing Starfighter 3000 for the first time, was kind of mind-blowing, as it was largely done by the ARM2.
There was a precedent for a 32 bit computer using a reduced address space and reserving the other bits for special purposes, and it was a huge one. The original IBM 360 mainframe architecture had a 24 bit address space in an otherwise 32 bit machine. That lead to a program address space of 16 megabytes. Of course many programmers exploited those 8 bits for many other purposes besides holding processor state information, which was probably more to do with that than holding the processor status as the IBM 360 had a separate, 64 bit program statue register (the PSW) of which 24 bits were for the current instruction address. Virtual memory addressing was also to come along with the IBM 370, to allow much larger physical memory spaces, but that 24 bit addressable programming space was to become an issue later with later versions of the architecture moving to 31 bit addressing and, later 64 bit, whilst retaining backwards compatibility. This is, by now, a familiar pattern with x86, SPARC, ARM treading comparable paths, albeit from different starting and end points. Whilst IBM 360s did use DMA, and did not use register banking, there was a competitor company that took the IBM 360 architecture a computer which was compatible at the user programming (non privileged) level, which did have it. There were no less than 4 levels of full or partial register banking used to speed up interrupt handling. That was the ill-fated RCA Spectra 4, the development od which was to all but bankrupt the company. RCA was to licence the Spectra to English Electric Computers, which when merged into ICL was marketed as the ICL System 4.
@@stevenclark2188 It was a sensible compromise back in the days when memory was expensive. It was extremely common for code to use tables of pointers, or linked lists using pointers, and using a few "spare" bits to contain various flags would save a significant amount of space. Certainly I used to make use of it when writing assembler code back in the day. The IBM 360 was designed back in the days of ferrite store, so 16 megabytes would have looked like a monumental amount of memory. Of course it also locked code using that technique into a particular version of the architecture.
Heh. I remember excruciating “type a letter” lessons on an RM Nimbus. The good news was that it was easy to take the network down and spend an hour dossing around by judicious application of a drawing pin with the old skool coax network cable..
at 18:50, when talking about the IOC, you imply that it's handling all the keyboard and mouse scanning. Actually, there's an Intel 8051 microcontroller that handles all that, and it talks (via the UART) to the IOC sending (and receiving) keyboard and mouse data.
0:28 "This is just the first one you happen to be able to buy in a shop". Hngh... My Dad bought one of the first Archimedes A305 on the first day of release in June 1987 from Cambridge Computer Store on Emmanuel Street, just across from the shopping centre the Raspberry Pi store is now. He was Head of Computing for our school which had a huge amount of Acorn kit, but if I remember correctly, Acorn didn't have any ready for shipping, but had put a few out to retail, so we popped into town with the school's order book. It wasn't long before he realised 0.5MB was woefully underspeccing it, even with Arthur OS, so we upped it to 1MB as soon as RS or Farnell could get the chips out to us. IIRC, the A310 and the A4xx models were delayed, probably due to RAM shortages I'd imagine.
Indeed, the Acorn Archimedes machines were available in stores to the general public almost immediately after launch: I bought an Archimedes 305 from The English Computer Shop in Antwerp during autumn of 1987, the second day it was available in Belgium. I was at the time still using a 1979 Sharp MZ-80K. The launch of the Archimedes instantly ended me doubting between buying a Commodore Amiga or an Atari ST. Incidentally, I just bought a Raspberry Pi400 this week, because the prices dropped with the launch of the Pi500 and because the Pi400 is AFAIK the last and most powerful machine able to run RISC OS. Just installed RISC OS today before watching this video.
@@koenlefever the Pi 500 can't run it? That's sad. Hopefully there'll be a port for it, the Pi 600 or 700 though as I'm not done with my Pi 400 yet, RISC OS or not.
Tiny, tiny correction: The RM PC186 definitely had sound. There was a Bach music "demo" that came with it and me and my school friends used to have fun pressing 'return' at the exact same instant on all the machines on the Nimbus network at the same time to cause a delightful musical cacophony. Also, we never had any BBC machines in our school, it was RM all the way, starting with a 380Z.
As someone who used these in schools in the early 90's really brings back memory's i remember running Maths circus on a3000 when i was really young then our county kept acorns in schools all the way upto the a7000 which i loved using then they switched to rm pc's.
My memories of playing Chocks Away! on an Archimedes during rainy Welsh lunch breaks in primary school in the mid-90s are much more graphically impressive than the tank games shown. Lemmings and James Pond were also popular. In year 6, my friends and I won an inter-school quiz held at Trawsfynydd Magnox Nuclear Power Station (decomissioned), the prize being an RM voucher which funded the school's first Windows 95 PC, and my first experience of the internet.
We had a few of these in the library at college in the 90s. They were leftovers from some earlier teaching program. I used to tool about with RISCos and play a bit of Zarch/Virus. It felt like my A500 with a bit more power, I was quite impressed.
ATARI ST afficionado here! Yes, the 3000 was really as fast as it could even software-emulate a ST a original speed. A shame this machine didn't made it's way into the homecomputer market as it should.
Obviously ARM took over the world. And Acorn died (mostly) RISC OS was the big loss, it was so far ahead of its time. However, you'd be correct in noticing that RISC OS and Windows 95 look _awfully_ similar.
The BBC Micro was what my UK primary school had in the nursery when I was there (4-5 years old). 3 years later, I was using Dorling Kindersley on PCs in the same school. It was wild how much progress was made. This was in the 90s.
Had these at school in 1993-6. Learning software like Ovation, Lego LOGO programming and other awesomeness. And Lemmings, SWIV, Zool etc. Way ahead of their time and I loved learning on these things.
I remember seeing an ad for the Archimedes in a magazine where it was doing a take on the Mac commercials where a Mac would be depicted with the word ‘hello’ written on the screen using the mouse in Mac Paint. But in this ad it was an Archimedes with the words: “Sorry Mac” The intention being to show that the Archimedes was better than a Mac.
Raspberry Pi has RISC OS so maybe that is a modern day Acorn? The Apple Mac is a little bit like an Acorn too with its ARM chip and Mac OS is a little bit like RISC OS if you squint hard enough! I heard even a popular music notation package came from the Acorn? But I wouldn't know about that because it's to do with sheet music and prefer a DAW 😅
RISC OS on Raspberry Pi is indeed the modern spiritual successor of the Archimedes. macOS, on the other hand, descends from NEXTSTEP/OPENSTEP and BSD UNIX, so it doesn’t really share any ancestry with RISC OS.
Being a viewer from across the pond, I really enjoy seeing what computer life was like over in the UK. Being a kid in the 80s then teen in the 90s (for me), it really was Apple / Commodore then PCs took over by the 90s.
Ah, excellent! Another RetroBytes video. A wonderful series of machines, in many ways years ahead of the competition... although Acorn didn't have the capacity to stay ahead for very long the descendants of these computers are everywhere and RiscOS is still being actively developed and used. The excellent OS kept me on the platform with a heavily upgraded RiscPC long after 'x86' surpassed it's headline specs. (I also have a stupidly upgraded A3000 because...)
These were AMAZiNG machines and the OS (RiscOS) sublimely good! 44:40 Castle Technology released something called a 'Kinetic' StrongARM card for the RiscPC with its own DIMM socket onboard, enabling the CPU to run at its full performance potential.
Used one of these at school when I was about 15. Never played games on it but I remember it being a pretty nice machine. Apparently RISC OS now has wifi support, so I will have to try it again on my Raspberry Pi 400 - I'd love a port for RISC-V too, as I have a Lichee Pi 4A (yes, I do have a lot of computer hardware although perhaps not by the standards of any retro-tech TH-camr). I never got to play games on it though, sadly; I assume nobody in the class had one at home to sneak games in. The coolest thing about it for this geek was the memory manager thing where you could change how much RAM each application got. All handled by the OS, now, of course. Now that I think about it, the art department had one too. Sadly I never got good at either art or programming!
i remember the A3000 well. i was the first to try it at my primary school and it was my introduction to using a mouse controlled GUI after years of using the older BBC computers
No mention of the RTC battery-leak debacle. I never owned an A3000 myself, but I did inherit one from a relative. Long story short, on opening it up for a looksie, I discovered the battery had leaked, badly. Things got worse when I tried to clean things up somewhat, with an anti-static brush and isopropyl alcohol - a bunch of inductors surrounding the battery fell off! Still have the A3000 knocking around somewhere, minus monitor.
Can anyone suggest any good A3000 emulators? as would really like to sell mine and with monitor soon but don't want to lose the programs my Dad wrote but don't have space to keep the hardwear and want to get off magnetic disks as well
I recall seeing the A3000 in a shop window in Tottenham Court Road (in its electronics heydays) and was working at the time, yet all I could do was drewl at that price. Was also some rumours of a cheaper model out soon shenanigans. Much like why I didn't buy a C5, even when I worked at Eastern Electricty Board at the time and could get staff discount at their shops back then, I got to see the brother for the C15 and was, that's more like it and another purchase that never happened back then. We all have those stories.
We got BBC Micros here in Australia too. I remember them up to Year 3 before they were replaced with Risc PCs. The desktop-y one you showed during the video that came after the Archemedes. It was a major leap over the primative-looking (for the 1990s) BBC Micro.
Ah, the joy of the A3000. Not a bad machine in all. The battery needs removing and replacing with one that won't spew its guts when you're not looking. The ARM2 can be replaced with an ARM3 board if you desolder the ARM2 and fit a socket. The memory upgrade pins are a pain in the arse though. You can fit 4MB to the board if you desolder the original memory, solder in the 4MB parts *then* locate the track which provides the 4MB access to the upgrade pins, trace it back to the 74LS( can't remember the number ) and tack in a tag wire from it to each RAM chip. Sorry for the vague, but it's been 30 years since I serviced Acorn machines. Datasheets will provide the answer regarding RAM pinouts. There's one pin that's NC on the 1MB parts which is addressable on the 4MB. With RISC/OS 3.1, an ARM3 and 4MB, they're a useable time capsule.
My A3000 sadly succumbed to battery damage some years ago. I would mention, however, that the A3000 was replaced in the range by the A3020. Arguably that was the very last Beeb.
Don't ever recall seeing one of these on the high street, the A3010 was in Dixon's by 1992 but was late compared to the established Amiga and ST, and still priced above them.
STM and LDM were super useful, they helped a lot with fast copying of memory, so helped a lot ehen you needed to blit graphics, and also made procedure calls so much less painful. Along with the condition flags, they helped an awful lot with code density.
Apple was one of the founders of ARM, they provided the cash. RISC was developed after compiled languages like C made it clear that most instructions in CPU's never actually got used so they could be removed and combinations of other instructions could be used instead in the small number of times they were used.
RiscOs is still available for the Raspberry Pi, and of course Acorn’s first ever customer for the Arm (Acorn Risc Machine before this) was Apple for the Newton!
The reason it does physical to logical mapping in the mmu is you can search all physical registers in parallel. The standard way of doing it is to have a larger table of logical addresses, but the chip couldn't contain them all. You could hold the most recently used. Which is basically how the mips r4000 mmu works. Or the mmu can walk the page tables in ram, which is how the 386 works. The r4000 mmu would have been cheaper and better than what acorn did, at the cost of having the cpu do more work when accessing a page that hasn't been used recently
Yes, it is associative memory but it effectively partitions the physical RAM. The difference between this and the MMU in the MIPS architecture is that MIPS has a TLB with the same kind of associative memory characteristics, but MIPS TLB entries can map virtual pages onto the same physical page, which isn't possible with MEMC. And MIPS TLB entries can involve pages of different sizes that are also unrelated to the amount of addressable memory. In contrast, the partitioning done by MEMC effectively imposed a uniform page size that was observed to be suboptimal for Acorn's systems that ran Unix on this chipset. The MIPS TLB also supports address space identifiers, so a large enough TLB could conceivably preserve mappings for different processes/tasks/domains, whereas MEMC doesn't seem to permit such persistence in a safe fashion. That means that an operating system is likely to want to flush the mappings on a context switch between processes. The result is that operating systems like NetBSD appear to use MEMC as a kind of TLB, anyway, albeit a rather large and probably largely wasted one.
I always remember there was a demo for the Archimedes that I think was called "planets" that had various 3D rendered planets. Can still remember the music for it, but not been able to find any traces of it or videos anywhere. I'm pretty sure I didn't imagine it
Surprised that you said school music departments would Habe an Atari ST. My school and sixth form college both wanted an ST but were told the policy was that only Acorn and RM machines could be purchased. They ended up with an A3000 and no music software since the budget didn't stretch to the eye watering cost of an optional MIDI module and the sole music package for the Archimedes (possibly an early version of Sibelius, which wasn't even a conventional sequencing package).
It was fun discovering this stuff, and it's good to find out how it works rather than take my approach which was to make fun of the BBC show Micro User and refuse to do a type in :D
Acorn Archimedes A3000 was released in 1989 with an 8 MHz ARM2 processor with the performance of 4 MIPs, for £1000. You'd have to wait another year before Sun released the SparcSYS 300, with a SPARC running at 25 MHz with a performance of 16 MIPS, for US$29K. But it was clocked at 3 times the speed. So most of that performance was clock speed.
Well, the SPARCstation 1, out in 1989, had a rating of just over 13 MIPS. The DECstation models using the MIPS R2000 were rated at around 14 MIPS and were available before the A3000 and Acorn's first Unix machine, the R140. What isn't mentioned here is that the floating-point performance of those other systems was vastly better than anything Acorn could offer, and although this was downplayed extensively in that era, it stopped Acorn from moving upmarket and was one factor in the company eventually running out of steam.
@ IEEE: Sun's SPARCstation 1: a workstation for the 1990s The architecture and features of the SPARCstation 1 are described and compared with those of other workstations and PCs of approximately the same cost. The heart of the machine is implemented using seven custom CMOS gate arrays plus a single-chip SPARC integer unit and a single-chip SPARC floating-point unit. The architecture of SPARCstation 1 reflects the use of CMOS technology, especially in the design of the SBus, which is SPARCstation 1's memory and I/O expansion interconnect. As a processing engine, SPARCstation 1 provides the user with 12.5 MIPS, 1.4 MFLOPS, and 64 MB of memory. Still not four times the processing power.
“In 1989 Sun introduced the SPARCstation 1, rated at 12.5 MIPS 20-MHz, 1.4 MFLOPS, for a base price of US$9000.” So 3 times the power was mainly due to a processor that ran at 2.5 times the clock rate. Some context - and not just price - helps to show how good the ARM RISC processors are even, the early ones. Remember it isn’t SPARC or MIPS that powers mobile phones and future desktop computers, it’s ARM. Putting things in true context shows how powerful - and efficient - even early ARMs were.
I never saw bbcs or archimides in school in the late 80s (did see a few bbcs at university in a lab in 2002 though!) but we had RM nimbuses and my primary had a 480Z. Our area seemed like an RM area! House is full of raspberry pis now tho ;)
Archimedes was way ahead of its time, a very underated computer which lacked the incentive for Home computing. I live in Australia and almost everyone owned a commdore or amiga, very rarely this computer was sold in computer shops, and not m,any peole knew much about it, but i did. I still have a soft spot for this computer and clearly it would of been a better choice had incentives and sales targeting was right. the international Launch on this machine was pretty much invisible to the gamer or enthusiast minded. Not many computer shops in my area promoted the BBC or archimedes, But i felt it was a Better choice then that of ots rivals Amiga or Atari ST
Its really a great machine. Somehow it still is alive... in every peoples phone. At least it's CPU. But I wonder: Did that BBC campaign of "computer education" really help advancing the UK in regard of "it literacy"? Are, lets say, 50 y/o in the UK more fluent on modern IT tech than their counterparts in France or Germany?
I'm not sure how older people deal with tech lol. When I was younger I came home to find our PC had a soundcard upgrade, a new CDROM drive and it was upgraded from Win 3.1 to 95. Somehow my parents were able to figure all of that out, but now ~30 years later they need help plugging an HDMI cable in.
Can't speak to the UK as a whole, or any other schemes in other countries, but for me it did kick-start an almost 40-year career in IT and software development. Still working in it today.
@@mycosys For Germany I am aware of the "Computerclub at the WDR" or some similar show on BR. But there is no document about a "ARD Micro" or a "ZDF Micro". Having the big public TV network deeply involved in education (like designing and basically promoting a product) seems to be more than others did.
I loved these computers at the time, I could explain from scratch at the age of about 12 why they were better than the Windows 3.1 Pentiums down the corridor, my I.T. teacher bullied me for being cleverer than him, and for having read ALL the books for the (at the time NEW!) RiscPC, which, like some Godlike being, sat there in the corner next to his normal Amstrad word processor, barely used because by his own admission he couldn't see a reason for it to exist! I never did get a Risc PC, I still want to play with one one day, but I reckon I'm less miserable today than Mr. Locket!!! My Maths teacher hated computers too, but my R.E. teacher, who you would expect to be a dullard, gave me a broken SCPH-001 (yes, that one!) which only required the power lead connector re-soldering, my evil parents made me give it him back, and then had him sacked. Screw being born in that town!
They should have included the DMA controller in the CPU. You pretty much always just want to copy from one address to another, you dont need any CPU registers or opcodes taking up time. Lots of MCU did DMA like this.
That would have involved are larger die size, which would have altered the economics of the chip cost. As over a certain size there in a none linear relationship bewteen yeild rate, and die size. The advantage of their FIQ appoarch was it used very little die space over what they needed without FIQ to just be a risc cpu. Later ARM cpus had far more space to play with, without the yield rate falling off a cliffe.
Surely the A3010 with the Green Function buttons came later? I had both. Then I went on to own and use a RISC PC 600 Twin Slice Model - and then added StrongArm PC & PC Co-Processeor :-) EDIT - got to the 42 minute mark where you mention the 3010 (and the 3020) EDIT2 - Also got at a later date a second-hand A4 (Still have it in fact) but non-working now.
Im pretty sure that I had seen archimedes on sale before this. The a3000 was a later computer that was aimed at the amiga 500 market. But the CPU wasn't fast enough for the computer it was in. If they had a 3d texture map chip, it would have totally destroyed the market The a500 needed more ram, so the price difference isnt as big
How did the initiative behind the BBC Micro go from "teach the next generation of software developers" to "teach the current generation of office workers" anyway? I've seen TH-cam documentaries on the program, but they tend to focus on the Micro and wrap up with some variation on "and then it was phased out".
I'm not sure the bit about the MEMC is entirely correct, The original caused MUL issues with processors with cache. My A310 came with the original and I replaced it with a MEMC1A which gave at least a 10% speed upgrade and also enabled ARM3 compatibility (which I did at a later date, a 36Mhz version at that 😁). I think the MEMC1A debuted with the A400 Series.
Qualcomm makes CPUs, they don't build Computers. And yes, every ARM based CPU in the desktop PC consumer market is a joke besides the capabilities of the current M4.
@@ThorstenDrews While I agree that Apple ARM CPUs are very impressive, the fact that they control everything from hardware to software plays huge part in the performance their systems have shown, it's not all about the CPU
@@guiorgy Which has been the strategy for Apple since about four decades. If they add a feature to the hardware it's probably because they need it for something in the software. Which is how you get rapid innovation. Microsoft (or anyone else) can't really do that. Their hardware is still very impressive though. Even without the software integration. I have an M1 mac Mini. It's still the fastest coumputer I have at home and it's completely silent. And it's the low end Apple Silicon.
@@Jonteponte71 Again, I'm not discrediting the hardware, as I said, it's very impressive (besides the soldered RAM and proprietary SSD), but it's not 100% clear how Qualcomm and Apple CPUs compare purely as a Hardware.
The part about 26 bit addressing is wrong. It's got nothing to do with 32bit word aligned addresses. If you look at your chart the chart you provided you'll find the 2 bits you gain through that are used for processor mode. Bit 25 is the highest bit we need for 26 bit addressing because we start counting bits at 0. Bit 0 through 25 are 26 bits.
The mode bits are set to zero (along with the status bits) when R15 is placed on the address bus during instruction fetches. Hence instruction fetches are 32-bit word aligned. This is clearly by design to ensure the PC was 32-bit word aligned. Why else would the mode bits be over in bits 0 and 1, separated from the status bits?
ARM really pushed memory use where others should have gone too and chunky pixels were ofc the future, but the 256-colour mode is just as cheating as EHB on the Amiga.
Wow.. a quick dive back.. that is to fast just to watch once (and could be a part of any second year IT course) that has many of the micro controller basics (or how to make a cheap one)...
I was the sales manager and then later the technical services manager of Orion Computers who were a decent sized Acorn dealer. We produced our own products and were a service centre with me being a component level service engineer. The 300, 400 and 400/1 were the predecessors with the 540 and unix boxes coming out just afterwards. The price was about the same as a bbc micro taking inflation into account. I was responsible for the A3000 podule expander :-) and we also did 1 and 4mb upgraded with the 4Mb replacing the 1Mb because the MEMC could only address 4Mb. The 540 had a MEMC for each 4Mb board with 16Mb max. The Econet module was the same :-) RiscOS was a really good OS. I loved the way the folder auto ran and all the setup files etc hide inside it and with relative addressing you could just move them about. I loved the Archimedes machines. I remember build several Econet networks but we had thin wire Ethernet at the shop/workshop.
I answered before finishing watching! We did get 8Mb on an A3000 but it was too expensive and like the Arm3 required socketing of surface mount chips! The 400/1 etc had socketed MEMC, IOS, ARM and VIDC so it was a bit easier :-)
We had one of these back in the early 90s, loved it and imo it has the best version of Lemmings (very important to a 5 year old!)
With the best version of the lemmings soundtrack by Matt Furniss
You always know it's going to be a good Saturday when a new @RetroBytes video drops.
The correct answer to Atari ST or Amiga is: Acorn Archimedes.
Deeply underrated, under appreciated computer that deserved better than being another educational system.
Totally agree!
It had its revenge even if it was served cold. Its ARM architecture is everywhere in mobile devices now, whereas Amiga and Atari ST are niche enthusiasts’ tinker toys
@@little_fluffy_clouds True, although ARM's days seem to be numbered with the rapid uptake of RISC-V. It's amazing how fast RV has gone from zero to where it is now.
I don't think RISC-V is an existential threat to Arm, just a financial one. Arm went from having effectively no competition to having to compete with RISC-V vendors in some market segments.
The A3000 was sold under the Archimedes name in Germany, without using Acorn‘s name. I remember ads for the „Archimedes A3000“ in German Amiga and Atari magazines.
It was the same in Sweden. I was an Amiga fan but was still close to buying this. Even got an ARM assembler book to start learning. It looked so cool but unfortunately I never got one. Would have been cool to have today :)
@@Jonteponte71 Were you one of the two people that bought Swedish PipeDream 3? ;-)
Blast from the past.
I had an A3000 in the early 90s. Loved it.
I was still rockin' the ZX Speccy +2 and got an Amiga a few years later, and PC with an Aztech "Quad Speed" CD drive. lol
But I would still fire up the A3000 very often.
The built-in BBC BASIC was great fun to mess with.
Dad bought the RISC OS 3.1 ROMs around 1994.
I had a Philips CM8833-ii as my main monitor through most of the 90s.
I used the monitor to watch TV and movies on, recording stuff off TV on a Sanyo Betamax VCR.
(things like Red Dwarf, Reboot!, X-Files, Games Master, and Bad Influence.)
Always had it all hooked up to a Rotel amp and speakers. lol
I still have four magazine floppy disks for the A3000. It's pretty much the only thing I have from that time.
One of the disks had a demo of Quark (shoot-em-up) on it.
On Halloween, I would often play No Excuses and Rotor, etc.
From the "Play It Again Sam" games pack.
Great times.
Seeing Starfighter 3000 for the first time, was kind of mind-blowing, as it was largely done by the ARM2.
There was a precedent for a 32 bit computer using a reduced address space and reserving the other bits for special purposes, and it was a huge one. The original IBM 360 mainframe architecture had a 24 bit address space in an otherwise 32 bit machine. That lead to a program address space of 16 megabytes. Of course many programmers exploited those 8 bits for many other purposes besides holding processor state information, which was probably more to do with that than holding the processor status as the IBM 360 had a separate, 64 bit program statue register (the PSW) of which 24 bits were for the current instruction address. Virtual memory addressing was also to come along with the IBM 370, to allow much larger physical memory spaces, but that 24 bit addressable programming space was to become an issue later with later versions of the architecture moving to 31 bit addressing and, later 64 bit, whilst retaining backwards compatibility. This is, by now, a familiar pattern with x86, SPARC, ARM treading comparable paths, albeit from different starting and end points.
Whilst IBM 360s did use DMA, and did not use register banking, there was a competitor company that took the IBM 360 architecture a computer which was compatible at the user programming (non privileged) level, which did have it. There were no less than 4 levels of full or partial register banking used to speed up interrupt handling. That was the ill-fated RCA Spectra 4, the development od which was to all but bankrupt the company.
RCA was to licence the Spectra to English Electric Computers, which when merged into ICL was marketed as the ICL System 4.
Program counter for MIPS was 26-bit. So it's pretty normal in RISC too.
@@stevenclark2188 It was a sensible compromise back in the days when memory was expensive. It was extremely common for code to use tables of pointers, or linked lists using pointers, and using a few "spare" bits to contain various flags would save a significant amount of space. Certainly I used to make use of it when writing assembler code back in the day.
The IBM 360 was designed back in the days of ferrite store, so 16 megabytes would have looked like a monumental amount of memory. Of course it also locked code using that technique into a particular version of the architecture.
Quite a different beast but BBC still do a micro, the BBC micro bit, also arm based 💪
Heh. I remember excruciating “type a letter” lessons on an RM Nimbus. The good news was that it was easy to take the network down and spend an hour dossing around by judicious application of a drawing pin with the old skool coax network cable..
Ah yes, the removal of the magnets on a rm coax network point - take a whole pc area down.
(tbh, I liked school and computers and that annoyed me!)
at 18:50, when talking about the IOC, you imply that it's handling all the keyboard and mouse scanning. Actually, there's an Intel 8051 microcontroller that handles all that, and it talks (via the UART) to the IOC sending (and receiving) keyboard and mouse data.
Brilliant video =D That tear down of the A3000 - was that your own machine, if so - please remove that NiCad battery!!!!
0:28 "This is just the first one you happen to be able to buy in a shop". Hngh... My Dad bought one of the first Archimedes A305 on the first day of release in June 1987 from Cambridge Computer Store on Emmanuel Street, just across from the shopping centre the Raspberry Pi store is now.
He was Head of Computing for our school which had a huge amount of Acorn kit, but if I remember correctly, Acorn didn't have any ready for shipping, but had put a few out to retail, so we popped into town with the school's order book.
It wasn't long before he realised 0.5MB was woefully underspeccing it, even with Arthur OS, so we upped it to 1MB as soon as RS or Farnell could get the chips out to us. IIRC, the A310 and the A4xx models were delayed, probably due to RAM shortages I'd imagine.
Indeed, the Acorn Archimedes machines were available in stores to the general public almost immediately after launch: I bought an Archimedes 305 from The English Computer Shop in Antwerp during autumn of 1987, the second day it was available in Belgium.
I was at the time still using a 1979 Sharp MZ-80K. The launch of the Archimedes instantly ended me doubting between buying a Commodore Amiga or an Atari ST.
Incidentally, I just bought a Raspberry Pi400 this week, because the prices dropped with the launch of the Pi500 and because the Pi400 is AFAIK the last and most powerful machine able to run RISC OS. Just installed RISC OS today before watching this video.
@@koenlefever I'm keeping hold of my Pi 400 exactly for that reason. I'm tempted to dye the Fn keys orange!
@@koenlefever the Pi 500 can't run it? That's sad. Hopefully there'll be a port for it, the Pi 600 or 700 though as I'm not done with my Pi 400 yet, RISC OS or not.
Tiny, tiny correction: The RM PC186 definitely had sound. There was a Bach music "demo" that came with it and me and my school friends used to have fun pressing 'return' at the exact same instant on all the machines on the Nimbus network at the same time to cause a delightful musical cacophony. Also, we never had any BBC machines in our school, it was RM all the way, starting with a 380Z.
Man, I thought the Amiga used some dirty tricks, but this is on another level. Amazing video!
I find it fascinating that this most premier of educational computers in the 90s happened to be ARM based. Talk about a head start!
As someone who used these in schools in the early 90's really brings back memory's i remember running Maths circus on a3000 when i was really young then our county kept acorns in schools all the way upto the a7000 which i loved using then they switched to rm pc's.
outstanding work!
thank you. Have a great xmas.
My memories of playing Chocks Away! on an Archimedes during rainy Welsh lunch breaks in primary school in the mid-90s are much more graphically impressive than the tank games shown. Lemmings and James Pond were also popular. In year 6, my friends and I won an inter-school quiz held at Trawsfynydd Magnox Nuclear Power Station (decomissioned), the prize being an RM voucher which funded the school's first Windows 95 PC, and my first experience of the internet.
We had a few of these in the library at college in the 90s. They were leftovers from some earlier teaching program. I used to tool about with RISCos and play a bit of Zarch/Virus. It felt like my A500 with a bit more power, I was quite impressed.
ATARI ST afficionado here! Yes, the 3000 was really as fast as it could even software-emulate a ST a original speed. A shame this machine didn't made it's way into the homecomputer market as it should.
Obviously ARM took over the world.
And Acorn died (mostly)
RISC OS was the big loss, it was so far ahead of its time.
However, you'd be correct in noticing that RISC OS and Windows 95 look _awfully_ similar.
The BBC Micro was what my UK primary school had in the nursery when I was there (4-5 years old). 3 years later, I was using Dorling Kindersley on PCs in the same school. It was wild how much progress was made. This was in the 90s.
The ST with a different CPU is actually a very good comparison 😊
Had these at school in 1993-6. Learning software like Ovation, Lego LOGO programming and other awesomeness. And Lemmings, SWIV, Zool etc. Way ahead of their time and I loved learning on these things.
I remember seeing an ad for the Archimedes in a magazine where it was doing a take on the Mac commercials where a Mac would be depicted with the word ‘hello’ written on the screen using the mouse in Mac Paint. But in this ad it was an Archimedes with the words: “Sorry Mac”
The intention being to show that the Archimedes was better than a Mac.
Raspberry Pi has RISC OS so maybe that is a modern day Acorn? The Apple Mac is a little bit like an Acorn too with its ARM chip and Mac OS is a little bit like RISC OS if you squint hard enough! I heard even a popular music notation package came from the Acorn? But I wouldn't know about that because it's to do with sheet music and prefer a DAW 😅
RISC OS on Raspberry Pi is indeed the modern spiritual successor of the Archimedes. macOS, on the other hand, descends from NEXTSTEP/OPENSTEP and BSD UNIX, so it doesn’t really share any ancestry with RISC OS.
You're thinking of Sibelius, which originated on the Archimedes before going multiplatform.
Being a viewer from across the pond, I really enjoy seeing what computer life was like over in the UK. Being a kid in the 80s then teen in the 90s (for me), it really was Apple / Commodore then PCs took over by the 90s.
Thanks for making my Saturday morning mate. Blessed us with another extremely interesting 45 ish minutes of computer history
Ah, excellent! Another RetroBytes video.
A wonderful series of machines, in many ways years ahead of the competition... although Acorn didn't have the capacity to stay ahead for very long the descendants of these computers are everywhere and RiscOS is still being actively developed and used. The excellent OS kept me on the platform with a heavily upgraded RiscPC long after 'x86' surpassed it's headline specs. (I also have a stupidly upgraded A3000 because...)
These were AMAZiNG machines and the OS (RiscOS) sublimely good! 44:40 Castle Technology released something called a 'Kinetic' StrongARM card for the RiscPC with its own DIMM socket onboard, enabling the CPU to run at its full performance potential.
Another masterpiece by RetroBytes! Your videos should be displayed in schools and on a retro computing events. I love them.❤
Love getting these suggestions in my feed. ❤
Quality upload again, champ.
Used one of these at school when I was about 15. Never played games on it but I remember it being a pretty nice machine. Apparently RISC OS now has wifi support, so I will have to try it again on my Raspberry Pi 400 - I'd love a port for RISC-V too, as I have a Lichee Pi 4A (yes, I do have a lot of computer hardware although perhaps not by the standards of any retro-tech TH-camr).
I never got to play games on it though, sadly; I assume nobody in the class had one at home to sneak games in. The coolest thing about it for this geek was the memory manager thing where you could change how much RAM each application got. All handled by the OS, now, of course.
Now that I think about it, the art department had one too. Sadly I never got good at either art or programming!
i remember the A3000 well. i was the first to try it at my primary school and it was my introduction to using a mouse controlled GUI after years of using the older BBC computers
No mention of the RTC battery-leak debacle. I never owned an A3000 myself, but I did inherit one from a relative. Long story short, on opening it up for a looksie, I discovered the battery had leaked, badly. Things got worse when I tried to clean things up somewhat, with an anti-static brush and isopropyl alcohol - a bunch of inductors surrounding the battery fell off! Still have the A3000 knocking around somewhere, minus monitor.
Can anyone suggest any good A3000 emulators? as would really like to sell mine and with monitor soon but don't want to lose the programs my Dad wrote but don't have space to keep the hardwear and want to get off magnetic disks as well
Arculator.
How much?
Saturday RetroBytes! Let's go!
Had an A3000 for about 2 weeks.... Returned it.... Bought an Amiga instead.
this is excellent, absolutely great explanation of the system
Good video, as always J. :)
I recall seeing the A3000 in a shop window in Tottenham Court Road (in its electronics heydays) and was working at the time, yet all I could do was drewl at that price. Was also some rumours of a cheaper model out soon shenanigans. Much like why I didn't buy a C5, even when I worked at Eastern Electricty Board at the time and could get staff discount at their shops back then, I got to see the brother for the C15 and was, that's more like it and another purchase that never happened back then.
We all have those stories.
We got BBC Micros here in Australia too. I remember them up to Year 3 before they were replaced with Risc PCs. The desktop-y one you showed during the video that came after the Archemedes. It was a major leap over the primative-looking (for the 1990s) BBC Micro.
Ah, the joy of the A3000. Not a bad machine in all. The battery needs removing and replacing with one that won't spew its guts when you're not looking.
The ARM2 can be replaced with an ARM3 board if you desolder the ARM2 and fit a socket. The memory upgrade pins are a pain in the arse though. You can fit 4MB to the board if you desolder the original memory, solder in the 4MB parts *then* locate the track which provides the 4MB access to the upgrade pins, trace it back to the 74LS( can't remember the number ) and tack in a tag wire from it to each RAM chip. Sorry for the vague, but it's been 30 years since I serviced Acorn machines. Datasheets will provide the answer regarding RAM pinouts. There's one pin that's NC on the 1MB parts which is addressable on the 4MB.
With RISC/OS 3.1, an ARM3 and 4MB, they're a useable time capsule.
Another excellent video, thanks
My A3000 sadly succumbed to battery damage some years ago. I would mention, however, that the A3000 was replaced in the range by the A3020. Arguably that was the very last Beeb.
I still have a RiscPC under the bed. It's on my list to one day see if I can get it going again. It was a wonderful machine.
This was once my dream computer. I even made a paper model of it :) I still remember the flight demo app.
Don't ever recall seeing one of these on the high street, the A3010 was in Dixon's by 1992 but was late compared to the established Amiga and ST, and still priced above them.
STM and LDM were super useful, they helped a lot with fast copying of memory, so helped a lot ehen you needed to blit graphics, and also made procedure calls so much less painful. Along with the condition flags, they helped an awful lot with code density.
Apple was one of the founders of ARM, they provided the cash. RISC was developed after compiled languages like C made it clear that most instructions in CPU's never actually got used so they could be removed and combinations of other instructions could be used instead in the small number of times they were used.
And this one has CTRL and CAPS LOCK at a sensible position! Yay!
RiscOs is still available for the Raspberry Pi, and of course Acorn’s first ever customer for the Arm (Acorn Risc Machine before this) was Apple for the Newton!
Awesome vid!
The reason it does physical to logical mapping in the mmu is you can search all physical registers in parallel. The standard way of doing it is to have a larger table of logical addresses, but the chip couldn't contain them all. You could hold the most recently used. Which is basically how the mips r4000 mmu works. Or the mmu can walk the page tables in ram, which is how the 386 works. The r4000 mmu would have been cheaper and better than what acorn did, at the cost of having the cpu do more work when accessing a page that hasn't been used recently
Yes, it is associative memory but it effectively partitions the physical RAM. The difference between this and the MMU in the MIPS architecture is that MIPS has a TLB with the same kind of associative memory characteristics, but MIPS TLB entries can map virtual pages onto the same physical page, which isn't possible with MEMC.
And MIPS TLB entries can involve pages of different sizes that are also unrelated to the amount of addressable memory. In contrast, the partitioning done by MEMC effectively imposed a uniform page size that was observed to be suboptimal for Acorn's systems that ran Unix on this chipset.
The MIPS TLB also supports address space identifiers, so a large enough TLB could conceivably preserve mappings for different processes/tasks/domains, whereas MEMC doesn't seem to permit such persistence in a safe fashion. That means that an operating system is likely to want to flush the mappings on a context switch between processes.
The result is that operating systems like NetBSD appear to use MEMC as a kind of TLB, anyway, albeit a rather large and probably largely wasted one.
I always remember there was a demo for the Archimedes that I think was called "planets" that had various 3D rendered planets. Can still remember the music for it, but not been able to find any traces of it or videos anywhere. I'm pretty sure I didn't imagine it
Many hours were spent playing Chocks Away on one of these machines 🙂
Surprised that you said school music departments would Habe an Atari ST. My school and sixth form college both wanted an ST but were told the policy was that only Acorn and RM machines could be purchased. They ended up with an A3000 and no music software since the budget didn't stretch to the eye watering cost of an optional MIDI module and the sole music package for the Archimedes (possibly an early version of Sibelius, which wasn't even a conventional sequencing package).
I just held a Raspberry Pi in front of the monitor and said "Look, there is your grand ... grand granddaddy." 😀
It was fun discovering this stuff, and it's good to find out how it works rather than take my approach which was to make fun of the BBC show Micro User and refuse to do a type in :D
The BBC Computer Literacy Project and Computer Programme were not designed to educate school children. The project was aimed at the general public.
11:50 I literally jumped from a 32k Electron to an Amiga 500. No regrets here either.
Acorn Archimedes A3000 was released in 1989 with an 8 MHz ARM2 processor with the performance of 4 MIPs, for £1000. You'd have to wait another year before Sun released the SparcSYS 300, with a SPARC running at 25 MHz with a performance of 16 MIPS, for US$29K. But it was clocked at 3 times the speed. So most of that performance was clock speed.
Well, the SPARCstation 1, out in 1989, had a rating of just over 13 MIPS. The DECstation models using the MIPS R2000 were rated at around 14 MIPS and were available before the A3000 and Acorn's first Unix machine, the R140. What isn't mentioned here is that the floating-point performance of those other systems was vastly better than anything Acorn could offer, and although this was downplayed extensively in that era, it stopped Acorn from moving upmarket and was one factor in the company eventually running out of steam.
@ IEEE:
Sun's SPARCstation 1: a workstation for the 1990s
The architecture and features of the SPARCstation 1 are described and compared with those of other workstations and PCs of approximately the same cost. The heart of the machine is implemented using seven custom CMOS gate arrays plus a single-chip SPARC integer unit and a single-chip SPARC floating-point unit. The architecture of SPARCstation 1 reflects the use of CMOS technology, especially in the design of the SBus, which is SPARCstation 1's memory and I/O expansion interconnect. As a processing engine, SPARCstation 1 provides the user with 12.5 MIPS, 1.4 MFLOPS, and 64 MB of memory.
Still not four times the processing power.
“In 1989 Sun introduced the SPARCstation 1, rated at 12.5 MIPS 20-MHz, 1.4 MFLOPS, for a base price of US$9000.”
So 3 times the power was mainly due to a processor that ran at 2.5 times the clock rate. Some context - and not just price - helps to show how good the ARM RISC processors are even, the early ones. Remember it isn’t SPARC or MIPS that powers mobile phones and future desktop computers, it’s ARM. Putting things in true context shows how powerful - and efficient - even early ARMs were.
35:19 Careful with the stock footage. Keep Putin's party out of it maybe.
A guy standing in a classroom?
@@seamusoblainn A classroom with a whiteboard saying "Project of the Party United Russia."
Most people are going to see this on a phone and not notice.
@@seamusoblainn Granted, it's a minor nitpick.
I never saw bbcs or archimides in school in the late 80s (did see a few bbcs at university in a lab in 2002 though!) but we had RM nimbuses and my primary had a 480Z.
Our area seemed like an RM area!
House is full of raspberry pis now tho ;)
“One sherbet dib-dab away from a war crime”: sublime humour 😂😂😂😂😂
Heh, "refreshes drams" in the subtitles. Without being capitalised as DRAMs, now it looks like the chip is filling whisky glasses ;)
Can you help me get a cs/2600 terminal server working / the software etc.
Ingenious chipset design. Pity ARM never went anywhere 😅
Second, then 😁 what an awesime surprise :3
Archimedes was way ahead of its time, a very underated computer which lacked the incentive for Home computing. I live in Australia and almost everyone owned a commdore or amiga, very rarely this computer was sold in computer shops, and not m,any peole knew much about it, but i did. I still have a soft spot for this computer and clearly it would of been a better choice had incentives and sales targeting was right. the international Launch on this machine was pretty much invisible to the gamer or enthusiast minded. Not many computer shops in my area promoted the BBC or archimedes, But i felt it was a Better choice then that of ots rivals Amiga or Atari ST
Its really a great machine. Somehow it still is alive... in every peoples phone. At least it's CPU.
But I wonder: Did that BBC campaign of "computer education" really help advancing the UK in regard of "it literacy"?
Are, lets say, 50 y/o in the UK more fluent on modern IT tech than their counterparts in France or Germany?
I'm not sure how older people deal with tech lol. When I was younger I came home to find our PC had a soundcard upgrade, a new CDROM drive and it was upgraded from Win 3.1 to 95. Somehow my parents were able to figure all of that out, but now ~30 years later they need help plugging an HDMI cable in.
Can't speak to the UK as a whole, or any other schemes in other countries, but for me it did kick-start an almost 40-year career in IT and software development. Still working in it today.
Yup, did entirely, many years in IT here too
What makes you think other western countries didnt invest in similar computer literacy programs in the 80s and 90s? They did. Massively. Still do.
@@mycosys For Germany I am aware of the "Computerclub at the WDR" or some similar show on BR. But there is no document about a "ARD Micro" or a "ZDF Micro".
Having the big public TV network deeply involved in education (like designing and basically promoting a product) seems to be more than others did.
:) One of recommended videos for this video is some "A3000: The last BBC Micro" video
Ahh yeah. I thought it was pretty powerful when I used one in the 90s. Wiped the floor with the very similar styled BBC
I loved these computers at the time, I could explain from scratch at the age of about 12 why they were better than the Windows 3.1 Pentiums down the corridor, my I.T. teacher bullied me for being cleverer than him, and for having read ALL the books for the (at the time NEW!) RiscPC, which, like some Godlike being, sat there in the corner next to his normal Amstrad word processor, barely used because by his own admission he couldn't see a reason for it to exist!
I never did get a Risc PC, I still want to play with one one day, but I reckon I'm less miserable today than Mr. Locket!!!
My Maths teacher hated computers too, but my R.E. teacher, who you would expect to be a dullard, gave me a broken SCPH-001 (yes, that one!) which only required the power lead connector re-soldering, my evil parents made me give it him back, and then had him sacked. Screw being born in that town!
Wow, I came here because I thought it was going to be a video about the Amiga 500.
They should have included the DMA controller in the CPU. You pretty much always just want to copy from one address to another, you dont need any CPU registers or opcodes taking up time. Lots of MCU did DMA like this.
That would have involved are larger die size, which would have altered the economics of the chip cost. As over a certain size there in a none linear relationship bewteen yeild rate, and die size. The advantage of their FIQ appoarch was it used very little die space over what they needed without FIQ to just be a risc cpu. Later ARM cpus had far more space to play with, without the yield rate falling off a cliffe.
Surely the A3010 with the Green Function buttons came later? I had both. Then I went on to own and use a RISC PC 600 Twin Slice Model - and then added StrongArm PC & PC Co-Processeor :-) EDIT - got to the 42 minute mark where you mention the 3010 (and the 3020) EDIT2 - Also got at a later date a second-hand A4 (Still have it in fact) but non-working now.
The A4 is loverly, but most of them are now saddly dead.
@@RetroBytesUK Basically it was a portable A5000
Can you make a video about the RM Nimbus? I'm really curious about that "IBM compatible-ish" comment.
It feels like a pocket enthusiast workstation might really have sold in the US with a killer app like Lightwave or whatever.
when the archemedes came out,automatically if you had a bbc/electron you would drool over the graphics in magazines
Im pretty sure that I had seen archimedes on sale before this. The a3000 was a later computer that was aimed at the amiga 500 market. But the CPU wasn't fast enough for the computer it was in. If they had a 3d texture map chip, it would have totally destroyed the market
The a500 needed more ram, so the price difference isnt as big
Nice!
My school had the Link 480Z
How did the initiative behind the BBC Micro go from "teach the next generation of software developers" to "teach the current generation of office workers" anyway? I've seen TH-cam documentaries on the program, but they tend to focus on the Micro and wrap up with some variation on "and then it was phased out".
I had an A3000 with a replacement cpu a arm 3 at 25 mhz
Throwing audio via graphic chip... and then fixing it with noise canceling... yep why not :D
I'm not sure the bit about the MEMC is entirely correct, The original caused MUL issues with processors with cache. My A310 came with the original and I replaced it with a MEMC1A which gave at least a 10% speed upgrade and also enabled ARM3 compatibility (which I did at a later date, a 36Mhz version at that 😁). I think the MEMC1A debuted with the A400 Series.
A400/1 series
Memc1a also gave the extra links, that allowed for more than 1 memc in a system.
one sherbert dip away from a war crime. awesome.
"Yes, someone is making an ARM based computer those days, and it's Apple"
Qualcomm: Am I a joke to you?
Yes, yes you are
Qualcomm makes CPUs, they don't build Computers. And yes, every ARM based CPU in the desktop PC consumer market is a joke besides the capabilities of the current M4.
@@ThorstenDrews While I agree that Apple ARM CPUs are very impressive, the fact that they control everything from hardware to software plays huge part in the performance their systems have shown, it's not all about the CPU
@@guiorgy Which has been the strategy for Apple since about four decades. If they add a feature to the hardware it's probably because they need it for something in the software. Which is how you get rapid innovation. Microsoft (or anyone else) can't really do that.
Their hardware is still very impressive though. Even without the software integration. I have an M1 mac Mini. It's still the fastest coumputer I have at home and it's completely silent.
And it's the low end Apple Silicon.
@@Jonteponte71 Again, I'm not discrediting the hardware, as I said, it's very impressive (besides the soldered RAM and proprietary SSD), but it's not 100% clear how Qualcomm and Apple CPUs compare purely as a Hardware.
please dust your BBC B. that picture makes me cry
The part about 26 bit addressing is wrong. It's got nothing to do with 32bit word aligned addresses. If you look at your chart the chart you provided you'll find the 2 bits you gain through that are used for processor mode.
Bit 25 is the highest bit we need for 26 bit addressing because we start counting bits at 0. Bit 0 through 25 are 26 bits.
The mode bits are set to zero (along with the status bits) when R15 is placed on the address bus during instruction fetches. Hence instruction fetches are 32-bit word aligned. This is clearly by design to ensure the PC was 32-bit word aligned. Why else would the mode bits be over in bits 0 and 1, separated from the status bits?
ARM really pushed memory use where others should have gone too and chunky pixels were ofc the future, but the 256-colour mode is just as cheating as EHB on the Amiga.
Memc giving data to vidc, is basically how agnus feeds video and audio to denise and paula. It's not anything revolutionary.
Wow.. a quick dive back.. that is to fast just to watch once (and could be a part of any second year IT course) that has many of the micro controller basics (or how to make a cheap one)...
i see...
overclocked my A3000 from 8 to 13MHz 😃
looks a bit like a1200 :)
Great. Now prices at eBay will sky rocket.
I'm afriad for the A3000 that ship sailed long ago.
@@RetroBytesUK what's that supposed to mean?
Background music is too loud and distracting.
"BBC Micro"? Isn't that an oxymoron? 😏