Yellow Pig's BBC Computer Pages

The BBC Master 512

Outline | Documents | Problems | Extra Info | Software | Photos | Home

About the Machine

The BBC Master 512 was a joint effort by Acorn Computers and Digital Research Inc. to produce a PC-compatible version of the BBC Computer. The real idea was that people who used a PC at work could have a single computer at home which both (i) would run "work" software, and also (ii) could be used as a standard BBC Computer with all the fun and educational advantages of that.

The system consisted of:

         A standard BBC Master 128.
    A co-processor board. This had an Intel 80186 processor (running at 10MHz) along with 512 kilobytes of RAM memory (hence the name of the machine).
    Software to make the system work. The operating system provided was DOS-Plus from Digital Research, intended to be compatible with both MS-DOS and DR's own CP/M-86. Also provided was DR's GEM (Graphics Environment Manager).
    A mouse, which plugged into the BBC Computer's "User Port".

Also provided were:

   a User Guide,
  a function-key assignment strip for GEM-Write, and
  a keyboard correspondence chart, matching BBC keys to those on a PC.

The co-processor board was usually installed inside the Master's case, connected to the Tube internally. It could, however, be put in a co-processor adapter box, and plugged into the external Tube connector. That way it could also be used with a Model B or B+, instead of an actual Master (provided the machine was equipped with ADFS), and it worked just as well except for a slight shortage of keys.

The 512kb of RAM was sometimes found limiting, and a few third-party companies produced an extension, doubling the RAM up to 1Mb.

Most users of the machine still referred to these variants as the "Master 512", even though the base machine might not be a Master, and it might have more than 512kb of memory!

Sadly the Master 512 was poorly supported. It was hard to find out information about it, or to find any guidelines about how to get the best from it. This was unfortunate because there were problems with the machine, but those of us who wanted to use it were left very much on our own.

I have decided to bring together on these pages some items that might be of value to anybody still interested in this machine, so click on one of the links below if you want more:

   Outline – A rather more detailed summary of what the Master 512 was, and what it was meant to be able to do.
  Bibliography – There was never very much published about the Master 512, but there were a couple of books and some magazine articles, in addition to the documentation that was provided by Acorn. None of this is still in print, but quite a bit has been made available on line.
  Problems and (a few) solutions – There were difficulties with getting the Master 512 to do what it was meant to. This is a brief account of these and (in a few cases) what could be done about them.
  Extra information – A miscellaneous collection of further information, designed to supplement the meagre amount otherwise available.
  Software – Some programs collected together with the Master 512 in mind, some of it designed especially for the machine.
  Photos – A small number of pictures that might just be of interest