Technology Technology

intro Intro Java Java ASP ASP PET PET BBC Micro BBC  
 

BBC Micro Archive


Three Decades of a Beeb

I bought a BBC Microcomputer in mid-August 1982. It was of Model B specification, though this was via an upgrade from an original Model A that had been done by the London based retailer. Over time, I added various standard peripherals such as dual floppy disk drives, an Epson FX80 printer and the Acorn Speech System (with the dulcet tones of BBC newsreader Kenneth Kendall).

I continued to use my Beeb for nearly thirty years until January 2012, when I finally gave it away. Before I passed the computer on, I transferred the data from my floppy disks to a PC. The disk images contained all the programs that I or various friends had written, been given or otherwise collected - plus loads of documents. I worked on the principle of getting rid of junk hardware, but preserving all the soft stuff!


Custom Hardware

Electronics had been a hobby of mine long before I got my BBC Micro. I was also interested in music, but more in terms of creating weird sounds rather than becoming a virtuoso player (I achieved grade 1 violin, but that was about as far as my formal training got!). Many electronics magazines contained designs for analogue synthesisers, so I was keen to have a go at building one. However: where would I get a keyboard from? Then, in 1981, the disused Presbyterian church in Maryport was being knocked down. On September 4th, I ventured into the half-demolished rubble and retrieved the huge wooden keyboard from the remains of the organ! I cobbled together some contacts for each of the 58 keys, complete with a resistor ladder, which could be used to drive a Voltage Controlled Oscillator. I build an entire (monophonic) analogue synth on breadboards and had endless fun making strange noises.

Once I'd bought my BBC Micro, I decided to build a new interface - digital this time - to connect the keyboard to the Beeb. The design was relatively simple, using the BBC's User Port (at address &FE60). Writing to the lower 6 bits would select a key, then reading the top bit would give a result showing if that key was pressed. It was then straightfoward to write software to access the keyboard and play music using the BBC's sound chip (with up to three notes of polyphony).

In my final year at university, my engineering project was "A Digital Audio Effects Processor". I built this using a "Profi-kit 2" Motorola 68000 based development system, with a Ferranti ZN432E A/D and a National Semiconductor DAC1022 D/A (both 10 bit). The results were pretty good, but the audio bandwidth was a bit limited due the processor requiring rather too many clock cycles (up to 32!) to perform many of its operations.

After finishing university, I built A/D and D/A converters for my Beeb. I dropped down to 8 bits, using Ferranti ZN427 and ZN428 chips. I never got round to making a proper PCB, so the design continued on breadboards right up until I disposed of the whole lot! I used the BBC Micro 1MHz Bus to interface the hardware to the computer. Writing to memory location &FCC0 would send output to the D/A converter; reading &FCC0 would return the current value from the A/D converter. Simple! Software I wrote included effects such as reverberation/echo, frequency transposition, emulation and synthesis. All of this took place in the first half of the 1980's.

Other, less custom, hardware I had included: a joystick connected to the on-board analogue port (with additional potentiometers on the third and fourth inputs); a light pen (though that never really worked satisfactorily); an EPROM programmer to allow me to burn my own custom sideways-ROMs; a 32K sideways RAM system that a friend donated to me (in 1986) after his old Beeb expired and he upgraded.


Photographic Evidence

I only have one, rather poor, photograph showing my BBC Micro with the church organ keyboard. It is from I circa 1983 and I've included it here in an attempt to show that I've not just been writing fiction!

BBC Micro with Church Organ Keyboard

You may also note my ultimate A/V system of the era, consisting of: a Tandberg Series 8 mono reel-to-reel tape deck; my brother's old record deck (not that I actually owned any vinyl discs!); a Decca CS1830 hybrid valve/semiconductor colour TV; a Pye "FenMan II" valve wireless (which had VHF FM, hence "FenMan"); a really cheap and nasty cassette recorder; all linked together via my own source switching unit built into an old biscuit tin.


Software

Nearly all of the software I preserved can be run in a suitable emulator on rather more modern hardware. For my own use, I have a version of BeebEm which I modified to also emulate my custom hardware (see above). For most of the software, though, the programs can be run using the jsbeeb JavaScript BBC Micro emulator. This doesn't, currently, seem to emulate the BBC Speech System (nor, of course, my own additional hardware!).

A selection of disks containing programs vaguely suitable for public consumption is provided below. The Disk Image name should give some idea of the types of programs on each disk. Clicking on the description should load and boot the disk up in an external instance of the jsbeeb emulator - noting that JavaScript will need to be enabled for that site.


Disk ImageNotes
General ApplicationsThe "LIGHT PEN" programs probably won't work very well in the emulator!
Miscellaneous ApplicationsDrink, date, lose weight, make decisions, work out where to go in London...
Family TreeThe data here is fictional, not the real family tree I put together in June 1985. Have fun trying to work out how to drive the clunky data entry system!
Adventure Games 1Play "ALBA VENTURE" while browsing the Alba House section of this Web Site!
Adventure Games 2
Adventure Games 3
Adventure Games 4Includes a couple of classics
Arcade Games 1I became "Elite" on January 18th 1985
Arcade Games 2"Breakout" won't work in the emulator, as I wrote it to use an analogue joystick
Arcade Games 3The first four games were originally just demos, broadcast as cassette tones over TV sound by Channel 4 on February 12th 1985 for their "Computer Buffs" series. I hacked them back into playability
Arcade Games 4
Board Games, Card Games and Puzzles"CLUEDO" was adapted from the Commodore Pet version (available elsewhere on this site!)
Educational Games
Simulation Games
Creative GraphicsSeveral of the pictures created here are saved on the next disk, for quicker display!
Graphics DemonstrationsYou don't need an Amiga to have a bouncing ball! Also, compare the picture of Alba House with the one in the Alba House section.
Digitised Pictures 1
Digitised Pictures 2The last nine pictures were captured using hardware built by one of my fellow university students as part of a third-year engineering project
Music Demonstrations
Music DevelopmentAll the programs here required my custom hardware, so won't work in a normal emulator. The code might be of some interest, though!
Speech & NoisesMost of these require the Acorn Speech System, so won't work in the current jsbeeb emulator
System UtilitiesSome of these used additional hardware (e.g. speech system, light pen, fast A/D converter), so won't be of much use in a standard emulator


Enjoy!

Welcome
Welcome!


Eclipse
Eclipse


Toolstore
Toolstore


Technology
Technology


Personal
Personal


Alba House
Alba House


Castlerigg Project
Castlerigg Project


Bookmarks
Bookmarks



The Personal Planet is maintained by Dave Wylie djwpptag David Wylie Last significant update: Sunday 13th February 2022 David J. Wylie