Yellow Pig's BBC Computer Pages

The BBC Master 512

Extra Information

The published information about the Master 512 was always very meagre. The collection of articles here is an attempt to plug a few of the gaps.

Most of these articles were originally circulated as a collection of documentation files on floppy disk. Here they have been slightly edited to HTML form for the Worldwide Web. Please remember that they were originally written in the early 1990's when Windows (Vn 3) was only beginning to catch on, and most PCs were still using the MS-DOS command line. Some of the references to MS-DOS etc may now seem rather dated.

Quite a bit of the information contained here is of a fairly technical nature. However, some of it may be of more general interest to 512 owners (many of whom have, in any case, been forced to become technically informed about their machine by the lack of help available on it!)

List of the Articles

			Configuring GEM – The GEM Setup program supplied with the Master 512 does not work. This article describes what possibilites there are for setting up GEM to your own preferences, and how to do it.

			FIDDLOAD – Documentation on the FIDDLOAD.COM program provided with DOS-Plus Vn 2.1. The program does not turn out to be terribly useful, so the information is of little more than curiosity value. Among other things, it is explained why you should delete the file from your boot disk!

			Key Correspondence – A summary of the correspondence (or otherwise) of the keys on the Master 512 keyboard with those of a standard PC-compatible.

			Display Control Sequences – A description of the control sequences recognized by the DOS-Plus screen drivers, and how you might use them.

			Special Floppy Disk Formats – A description of the two floppy disk formats, 800kb and 640kb DOS, unique to the Master 512

			Operation of the Screen System – This includes a description of the screen modes available, a discussion of the memory map, some comments on how the 512's system works, and some notes about the differences and deficiencies of the 512's video system when compared with a genuine CGA on a PC-compatible. (Although there are a few more technical ideas referred to in this document, most of it can be understood without them.)

			DOS-Plus Interrupts – This lists the ways in which the interrupts supported by the 512's implementation of DOS-Plus differ from those which exist in a normal MS-DOS machine. It includes details about which are omitted, which are different, and what extras there are. Mainly for serious programmers, this document.

			Using the XIOS – Some extra facilities unique to the 512 have been written into the system for the use of programmers. This file indicates how they may be used. Again, for the more technically minded.

			The Tube and the 80186 Co-processor – An outline of the "low-level" operation of the Tube, particularly as it relates to the Master 512. Much of the information here is very technical, and unlikely to be of much use to many people. However it is included with this collection because I had to discover most of it the hard way when I was writing a program which needed to use the Tube in an unconventional manner. There might be somebody else somewhere for whom the information would be useful!