I once had a BBC Model B Microcomputer

Grenville Armitage
First release 17 July 2011
 Created thumbnail images 23 April 2012


This page is largely for my own benefit, although I've written it in the hope it will be useful to others (like you, if you're reading this page and you aren't me).

My second personal computer -- the "BBC Model B Microcomputer"

Back in 2002 I unearthed my old "BBC Model B Microcomputer", an impressive (in the early 1980s) 6502-based machine made by Acorn Computers in the UK. I obtained one when it was new, did a lot of programming on it until the late 1980s and then hid it under a bed. While I moved house a few times over the ensuing years, the BBC Model B stayed hidden along with all my old notes, printouts and genuine 5-1/4" floppies. In 2002 I made a partially-successful attempt to recover my old software from
the 5-1/4" floppies, and documented my experience. (I made some good progress until my floppies literally started falling apart inside my old drives, clogging the heads. These floppies were around 20 years old, and the magnetic particles started stripping off where the drive head touched the disk surface.) I revisited the task of recreating floppy images in 2005, and now (2011) I have finally gotten around to documenting what I've recovered.


The BBC Model B Microcomputer

The BBC Model B Microcomputer (or just the "Beeb") was based around a 2MHz 6502 processor, had bit-mapped and Teletext graphics modes, came with 16K or 32K of RAM, and supported the use of 8K and 16K ROMS to hold various languages, operating systems, and applications. The keyboard and motherboard shared the same box, with UHF output for displaying on TV screens and an RGB output for monitors.

More detailed technical specs (and a whole lot more) can be found at Rob Schmidt's "The BBC Lives!" website.


My own Beeb

My particular Beeb had 32K RAM, OS 1.2, BASIC 2, Disk Filing System (DFS) 0.9E, four-channel analog to digital converter (ADC)  interface, casette interface, parallel printer port, an 8271-based disk interface and two 5-1/4" floppy drives. I had also developed and installed a ROM-based memory editor/disassembler known as OZMON. The keyboard connector was a bit loose after all these years, but after a few wiggles the Beeb booted up like new! The disk drives still appeared to work, and I was able to format and read/write a blank 5-1/4" flppy. So far so good.




Emulating a BBC Model B Micro

As of July 2011 my personal favorite emulator is BeebEm 4.13 (BeebEm413.exe) -- I have utilised the Windows version of BeebEm under Windows 7 and also
under PC-BSD 8.2 using Wine 1.3.21 (specifically the PC-BSD PBI for Wine) .  A longer list of emulators is available at http://www.stairwaytohell.com/emulators/homepage.html as of July 2011.


Some of my own software

I worked on a range of projects for my own entertainment back in the mid-1980s. Here is a short list, with links to some binaries, source code and/or documentation in a few cases.


Last Updated:Wednesday 25-Apr-2012 14:56:44 AEST