The Model A of when?
Guys, I know it's horrifying but at this stage 1981 was a lot more than 15 years ago.
The BBC Micro:Bit will start rolling out to all year-seven pupils in the UK from this morning. What the kids will receive is a matchbox-sized single-board computer with 256KB of flash and 16KB of RAM, manufactured by element14. Yes, you read that right, the same amount of RAM as the Acorn-designed BBC Micro Model A of 35 …
Sadly I know 1981 is more than 15 years ago. Seeing as I was born that year.
You think you have it bad? 1983 was when I first started programming, on a rubber thump Spectrum. The only computer we had at school was an Apple II and I never even got to see it because only the maths swots were allowed into the hallowed room :-/
Didn't stop me developing what has become a 35-year-and-counting programming career though :)
What is this. A Willy Waving competition?
I graduated from University in 1981, having already worked with UNIX for three years (very progressive university, Durham)!
And, although it was launched in 1981, most people who placed an order for a Beeb when they opened the process (like me, model B, issue 3 board, serial number 7000 and something, still working) waited more than 6 months to actually receive theirs.
I'm just waiting for the real gray-beards who make me look young to wade in with their PET, Apple ][ and Altair stories.
Grey Beard reporting in (white actually but that's genetics for you)
Back in about '79 '80 I hired a Commodore PET from a supplier just to show it off to my boss and what it could do. Crackin' machine way ahead of it's time as an All in One box
Well I say hired I borrowed it from the dealer for a small fee\deposit , probably his beer money for the weekend.
"I'm just waiting for the real gray-beards who make me look young..."
Duly obliging. My Apple II was bought in 1979 on the last day before the selective VAT for electronics kit was raised from 8% to the then general 15%.
However,,, my Motorola development kit was bought in 1976. Motorola 6800 and a full complement of 1KB of static RAM. Unfortunately you also needed a Teletype to drive the human interface. An enormous manual had the logic diagrams and software listings for all sorts of ways to use it to drive bits of hardware. It was a view into a new world where hardware like bar code readers used software rather than TTL chips.
My first real playing with a computer was back in 1967 when I transferred to the company's System's Test department. I could spend as long as I liked trying to break a massive 1MB prototype 3rd generation mainframe in any way I could devise.
Come to think of it - most of my 45 years in the IT industry was a case of being paid to "play" with computers. Now I'm retired it is just a hobby - with no PHBs to spoil the fun. The only difference over that time is that computer/electronic bits have become faster and much, much cheaper ..and the willy doesn't wave so much these days.
"BBC Micro Model A of 15 years ago". The BBC model A was introduced in 1981. Clearly history (or simple arithmetic) is not the authors strong point.
"Micro:Bit’s two ARM Cortex MPUs are descended from the Risc chips of that old Acorn machine." Again complete inaccurate, as the BBC micro used the MOS 6502 processor. It was the later Archimedes that used the first ARM chips.
I don't dare read any further.
Fast page 0 access on the 6502 was a major feature, well used in the Beeb for OS vectoring and frequently used counters (like buffer counters), which made extending the OS possible to even moderately competent machine code programmers.
In many ways, the 6502 was a model for RISC processors. Simple, many instructions executing in a deterministic small number of clock cycles (OK, maybe not single cycle, but better than an 8080 or Z80), very regular instruction set (as long as you ignore the missing instructions that did not work) and with enough useful addressing modes.
Mind you, it was simple because of the limited transistor budget available, rather than a desire to create a RISCy processor.
Fast page zero access was used on the PDP-8 architecture - a few years before the 6502 appeared. Goes to show that there is nothing new in computing - just new names for the same old stuff.
Phil.
p.s. Got my PET 2008 in 1979. Still have it but scared to turn it on in case the electrolytics decide to expire.
Not entirely inaccurate though:
https://en.wikipedia.org/wiki/BBC_Micro_expansion_unit#ARM_Evaluation_System
"ARM Evaluation System
As one of the first production RISC processors, the ARM Evaluation System was part of the development programme leading to the Acorn Archimedes and its early Arthur operating system. It was not branded "BBC", but it is physically contained within the family's "cheese wedge" case. The ARM 1 processor was clocked at 8 MHz, and was fitted with 2 MB or 4 MB of RAM.
In 2006 a new ARM processor board using an ARM7TDMI processor was designed and sold, without an enclosure but able to fit within the original case."
Didn't the Model A have a 6502? Which might have a small instruction set, but it wasn't RISC... Due to complex addressing modes, mostly. And variable length instructions. While it had minimal registers and used ram instead, that was mostly because getting registers on die was seriously expensive in the 70s.
6502 registers limited? Pah! We had loads to choose from! A, X and Y for a start. Then we had the status register, a stack pointer (generally best left to the processor itself, but you could have fun manipulating it) and a program counter (current execution address).
It was a dream compared to the Z80.
I have programmed many different types of machine at assembler level - even hand coding in octal/hex. However I have never felt any attraction to learning the Intel instruction set. I was spoiled by the orthogonal mainframe instruction sets - and the 6502/6800/68000 carried on that clean architecture.
With the enormous gate capacity of modern silicon it is a bit of a mystery why no one has implemented the ICL VME target instruction set. IIRC Its data descriptors stopped slack coding from producing buffer overflows - variables' data typing was policed by the hardware.
The caption to the photo at the bottom doesn't seem quite right. The computer in the picture looks to me like an Acorn Atom. Was this Acorn's first 'kids' computer? Well, maybe. I was a kid and I certainly had one (and spent hours explaining to my ZX81 owning school friends that a real keyboard was actually rather important).
Probably a pre-production Atom - it should have the Acorn Atom logo to the right of the spacebar - unless it's just the way the light is falling there doesn't appear to be one here. It could possibly be a mockup using an Acorn System 2/System 3 keyboard - this used the same case moulding as the Atom.
What a pair of posh gits! I saved for my zx81 from my paper round and it was significantly more than a week's wages at a few quid a week even second hand (around about £50 IIRC). Can only guess that someone bought one and got bored quickly because I bought mine before the Spectrum came out.
Would have loved the more advanced BBC but waaay out of my early teenage price bracket
I'm glad somebody mentioned this. You can recognise a BBC Micro very easily because of the "ashtray" hole (or overlaid gap or, if you fitted one, a ZIF socket) on the left of the keyboard which the Atom never had.
As for being the first "kids" computer, as I recall, the BBC Micro was part of a literacy project that was aimed not just at children but a general audience. It only really became a large part of the childrens' market when the government of the day put in a project to partially fund schools buying computers for the classroom as long as they were British which led to 75% (roughly) of schools buying BBC Model Bs (mainly), the rest tending to go for Sinclair Spectrums. Even taking that into account, the Beeb was never the biggest seller for kids outside schools, not even in its Electron form.
I didn't get one until I was well into my A level days. I still have it, too! ;)
The other systems on the school list was the Research Machines 380Z/480Z systems, which were, IMHO, less useful in the classroom than the Beebs, although one could argue that they may have had more potential for business type computing as they could run variants of CP/M and associated software which was the microcomputer OS of choice for business prior to the IBM PC.
They were also much more expensive!
I think that the Newbury Newbrain was also on the list, but nobody bought them!
I remember my school had the RM 480Zs, although I had left by then, but my younger brother got to play with them.
The school my Dad taught at, in Sheffield, got Sharp MZ80A's though, I remember him bringing one home to "test"... ahem... as he was the member of staff responsible for AV resources - which included computers, in those days.
The local technical college had an RM-380Z in, erm, 1979. It was where us sixth formers from the local grammar school who wanted to do O-Level computer science were sent because they actually had access to a computer.
At the start of the new course, we were using a leased line to an Open University computer. Once the first bills for that came in, various faces went white and, although the 380Z was appallingly expensive, it was seen as a bargain in comparison.
I broke it for about a week by inserting an 8" floppy the wrong way around...
Technically it is the same amount of RAM, but on the BBC Micro that RAM had to hold application code, the screen buffer (up to 10K on the model A) and working variables, stack, etc. - this could leave, depending on graphics requirements only about 5K for code. On the Bit, I assume application code will go into flash, and there is no screen buffer to speak of, so the 16K is only necessary for working variables, stack, etc., and code can be much larger.
BTW - I think you might have meant 256KB and 16KB rather than 256Kb and 16Kb.
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16KB OS, 16KB Basic, with other ROM based language or OS extensions paged into the same address space as Basic.
The ability to switch into and out-of a paged ROM to handle OS extension calls without disrupting the running programs was an extremely clever piece of design that overcame what should have been a serious limitation of the Beeb. Put some RAM in the same address space, and you could do some really clever things.
Beeb had the OS and BASIC in a masked ROM, and add ons were either masked ROM or EPROM. Useful, as I recently changed my B from DFS to DNFS just by UV wiping the EPROM and blowing the replacement ROM image into it.
Downloaded from the Internet, burned into EPROM, installed. I guess this is piracy, eighties style. That and dub tapes of software that throws up never ending load fails. ;)