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30 Years of the BBC Micro
Alioth writes "The BBC has an article on the BBC Microcomputer, designed and manufactured by Acorn Computers for the BBC's Computer Literacy project. It is now 30 years since the first BBC Micro came out — a machine with a 2 MHz 6502 — remarkably fast for its day; the Commodore machines at the time only ran at 1MHz. While most U.S. readers will never have heard of the BBC Micro, the BBC's Computer Literacy project has had a huge impact worldwide since the ARM (originally meaning 'Acorn Risc Machine') was designed for the follow-on version of the BBC Micro, the Archimedes, also sold under the BBC Microcomputer label by Acorn. The original ARM CPU was specified in just over 800 lines of BBC BASIC. The ARM CPU now outsells all other CPU architectures put together. The BBC Micro has arguably been the most influential 8 bit computer the world had thanks to its success creating the seed for the ARM, even if the 'Beeb' was not well known outside of the UK."
People used to get excited when a CPU clock was measured in MEGAHERTZ! Now we're jaded...
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Programming with 6502 assembly... all of us cool kids were doing that back in those days.
The most remarkable thing about the BBC is that they're still going running production code.
I had the good fortune of working with (or rather, near) one of these systems a few years ago. When I asked why they hadn't upgraded the machine in nearly 3 decades the head of the system simply responded; "It still works."
The first computer I ever used was a BBC Micro. It was around 1986 in a small private boarding school in the middle of the bush in Zambia. We were over an hour's drive from the nearest telephone. The school got one or two of these computers just before I left, and somehow they got me hooked on computers.
The only command I still remember was that you had to type "CHAIN" to run something. I've been curiours about that command ever since, but a quick Google search leads me to believe that it "chained" the LOAD and RUN commands together.
www.clarke.ca
Back in 1998 when I was in the 5th standard my school provided us some very old bbc micros to learn basic. It was small (no separate cpu cabinet ) and was efficient for all that it could do.
Changing the screen mode 3/4 of the way down each screen refresh. Programming while counting every clock cycle - fantastic. I still wonder where all the resources are wasted in current software. I still say FRAK! when the need arises. Nobody knows what I'm talking about :(
We used to have a room full of them at school and we soon discovered if you rubbed your feet on the carpet and then pushed your locker key in between the keys to the exposed circuit board... they stopped working.
The irony is I later in life wound up maintaining student labs for a university and had to put up with "dickheads" like I forgot I used to be...
Elite, developed for the BBC Micro and published by the same company that made the Micro, did get a lot of attention here in the U.S. (it was ported to all the major platforms). It was one of the first big universe sandbox games, and modern games like EvE Online are still influenced by it.
SJW: Someone who has run out of real oppression, and has to fake it.
I wrote a 6502 disassembler/monitor thus removing the need for such shenanigans.
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
A slightly more informative article.
I remember we had three of these on trollies in my primary school - two had colour monitors, and one had a black and white monitor. Somehow I managed to network/schmooze/brown nose my way into becoming a "computer mover" when I was in the 5th year with two of my friends. We were tasked with moving the computers first thing on a Monday morning into a new classroom, who would then have it for a week. We'd plug it in, turn it on and load up the correct disk that the teacher wanted to use. I think that's where my love of computers came from right there. They were really good computers for their time. I gather that they were expensive, which is why they didn't find their way into many homes. However, a generation of British children did indeed grow up using them.
The BBC Micro at 2MHz was considerably faster than the Spectrum at 3.5MHz. The Z80 is a CPU that I like (I still write Z80 assembler, indeed I'm much more proficient at Z80 than 6502 and I've designed and made an ethernet card for the ZX Spectrum fairly recently as a fun retro project). However, we have to consider this. The fastest 6502 instruction executes in 2 T-states, most execute in 3 T-states, and the slowest take 7 T-states. The fastest Z80 instruction takes 4 T-states and the slowest over 20 T-states. The 6502 therefore has better interrupt latency (that monster 23 T-state index register instruction on the Z80 can't be interrupted).
The other thing the 6502 has going for it is the very fast zero page instructions, which are tantamount to giving you 256 extra registers.
The competing ZX Spectrum also had contended memory. Thanks to the 6502's predictable memory cycle when compared to the Z80, the BBC Micro designers could interleave screen memory access with CPU access, so no memory is contended. The Spectrum has to pause the processor while the ULA accesses the screen memory, meaning anything in the lower 16K of RAM takes a noticable performance penalty (and you can't use the lowest 16K for anything timing critical that must run while the ULA is reading the frame buffer).
Don't get me wrong, I love the Speccy, it's probably my favorite 8 bit (and I own several!) - it did an awful lot for very little money, it was immense value for money - but the BBC Micro was at the time had excellent performance.
Oolite: Elite-like game. For Mac, Linux and Windows
What Braben and Bell did to get this running on the BBC makes for pretty interesting reading.
http://en.wikipedia.org/wiki/Elite_(video_game)#Technical_innovations
Summation 2
No, it's not at all related to the Ohio Scientific. The only thing they have in common is they are both 6502-based.
Oolite: Elite-like game. For Mac, Linux and Windows
Aside from Elite, one of the classic games for the BBC was Citadel. I'm still amazed how it managed to fit about 100 screens worth of platform adventure game into 12k of memory without touching the disk after it had loaded. IIRC it ran in mode 2 - which took 20k out of the available 32k memory. I think they only used part of the screen and used the rest for storage with some weird trick to make it invisible. The Electron version (see link) couldn't do the hiding trick somehow.
The BBC version also spoke to you when the menu program loaded up, and to this day I think of it as "Seeta-toddle", which gives you some idea of the audio quality.
For those who are curious, there is a wikipedia entry here: Citadel (video game).
http://www.reghardware.com/2011/11/30/bbc_micro_model_b_30th_anniversary/
It was roughly contemporary to the Commodore 64 and Atari 800/800XL micros. More expensive than both of those, but cheaper than an Apple II, which were very expensive in the UK. The Apple II predated it by about 4 years if I recall. My impression at the time was that the Sinclair ZX Spectrum (Timex Sinclair in the US) was far more popular in the UK, along with the C64. The BBC was common in schools, but less common at home, mostly due to a dearth of games and pricing. A cheaper version, Electron, was released later to combat this, but too late.
It's a Unix system - I know this.
I grew up programming advanced Java routines on a difference engine. Your BBC Micro and your ZX81 have nout on me.
"That's the way to do it" - Punch
Ones the eye candy novelty factor has worn off which takes, ooh , 3 minutes , no one cares one way or the other. All it does is waste energy by forcing the GPU to do pointless calculations. You couldn't have picked a worse example to explain why computers are better today.
Was the Beeb available before the Apple ][ ? Was it more or less expensive in the UK?
I get the feeling that the BBC Micro enjoyed a kind of tax protected status, the way American made pickup trucks do in the US.
The BBC came quite a while after the Apple II - if you've been following the 30th Birthday announcements, its actually younger than the IBM PC (...of course, the IBM was eye-wateringly expensive for a few years, until the Clone Wars began).
I've programmed both and, generally, the BBC was considerably more powerful than the Apple.
It had a (much) better BASIC with 'structured programming' facilities (Repeat/Until loops, multiline if/then/else named procedures), a built-in 6502 assembler (so you could use BASIC as a macro language) and neat indirection facilities for working with bytes/words/strings in memory. Unusually for "home" computers of the time it had a 'proper' operating system, quite separate from BASIC - the BASIC ROM lived in a paged memory space alongside applications such as wordprocessors and other utility ROMs such as the disc filing system (popular BBC expansions included extra ROM sockets for applications or 'sideways RAM' for use as a RAMdisk or to let you develop your own ROMs).
The graphics were much better (but with a caveat) than the competition - 160x256 in 8 colours, 320x256 in 4 colours or a TV-tousing 640x256 in monochrome. Also, those colour modes were fully bit-mapped c.f. the attribute-based solutions on other systems (where you could e.g. only have 2 colours in each 8x8 cell, or on the Apple where you could only plot white by plotting a magenta pixel next to a green pixel). There was a proper palette system (so you could do fast animation by palette switching - only TTL though so its always the same 8 colours) and 'hardware' scrolling by tweaking the memory mapping (which could also pull tricks like changing display mode half-way down the screen, as used in Elite). The caveat was that the RAM was shared between data and video - so the higher modes used 20K out of your 32K. Although aftermarket upgrades appeared that added a 20K page to replace the video RAM (which worked seamlessly provided that the application used the correct OS calls rather than poking things directly) Acorn took their own sweet time before building that feature into later models.
It also had a shedload of internal hardware: a Teletext-compatible character generator chip for low-memory, high-quality TV friendly 40 col text & block graphics (without eating your RAM); a 'proper' sound generator chip; analogue inputs (not audio frequency, but great for proper joysticks and school science experiments) and a 'user port' which made about half of a 6522 VIA chip available for digital I/O, a serial port, parallel port, proprietary expansion port & vacant sockets on-board for a floppy controller and 'econet' LAN... Plus a really decent keyboard (the kind with discrete key-switches for each key). Then there was Acorn's 'Tube' interface, which allowed you to hang off a 'second processor': i.e. a headless 6502, Z80 or (later) 32016-based computer that used the BBC as an I/O processor. (Of course, the really interesting one was the ARM second processor, but AFAIK that was never publicly available).
The Apple's advantages were (a) software base (but the BBC accumulated quite a big software base in the UK) and (b) internal expansion (the BBC had lots of expansion potential but it was either via external interfaces or slightly kludey piggyback boards). I think there were more options for upgrading an Apple 2 to '64K clean' RAM configuration.
However, If you got the BBC 6502 second processor (a 4MHz 6502 with 64k RAM, with the original BBC handling all the I/O) then anything else with 8 bits (and quite a few things with 16) could eat your dust... unfortunately the price of that hampered adoption and, hence, software support (although you could play the definitive version of Elite).
The BBC B cost ~£400 - but
In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
I loved Micro Men. The Beeb show absolutely no interest in releasing it on DVD, but it's on YouTube. I'm getting really fucking tired of waiting for banner ads to load on YouTube, but if you want to see it, start here.
Some of the original people have cameos, like Sophie Wilson as the exasperated barmaid toward the end.
...laura
The current ARM has little to do with the BBC micro. Apple purchased a stake in Acorn with the goal of getting them to FAB a low powered CPU to power the Newton.
...except that if the 6502 BBC micro hadn't happened, Acorn wouldn't have developed the ARM2/3 to use in the next gen BBC Micro and there wouldn't have been anything for Apple to buy in to. It may have evolved since then, but Apple sure as hell didn't invent the ARM.
The first ARM-based machines were the ARM2-powered Acorn Archimedes range, released in 1987, the entry level model of which was still branded as "BBC Micro". At the time, they kicked sand in the face of 80286-based machines. The Newton didn't appear until much later.
Cheekily, in 1994, Apple touted their new PowerPC-based Macs as the first RISC-based personal computers.
In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
Great memories with this computer. And it was so far ahead of all competitors : even the predecessor of the Acorn BBC B (the Electron) already had 2Mhz and 32KB RAM and was networkable using a thing called Econet.
The BBC B+ could be expanded up to 128KByte and had a second processor (we're talking 1986 !!!!), teletext-reader, lightpen that allowed you to draw by using a pen on your screen (think tablet !) and so on.
And then Archimedes with its 32-bit RISC CPU came in 1987 (!), doing 4 MIPS and offering a Windowed operating system that booted from EEPROM instantly (switch it on and it's there).
Any mobile device with an ARM chip (think Android, tablets, Blackberry, etc.) is based on the architecture that was spawned in the 80s by Acorn (ARM = Acorn Risc Machine).
I'm glad and privileged to have worked with those great devices !