Several factors such as the decreasing cost of disc systems, the shortage of official disc upgrades, and Acorn's policy of only supplying the DFS to dealers has prompted a number of suppliers to try and provide alternatives disc filing systems. One such supplier is Watford Electronics referred to from now on as WE. We have had a pre-release version of their DFS together with a manual here at Beebug for some time, and report below on our findings.

The DFS will be supplied in a 16k EPROM (The Acorn DFS is 8k) and will have a manual to accompany it costing £7.50. The ROM fits as usual into one of the sideways sockets, and the manual is there to tell you all you need to know about using the Disc System. Cost will be around £42 for the DFS, and around £85 for the complete upgrade kit. Watford Electronics will exchange their DFS for the Acorn DFS for £38. ALL prices are exclusive of VAT.

The manual is quick to point out that the WE DFS is an enhanced version of the Acorn system. Indeed all the normal DFS commands are available (see Beebug Vol. 1, No. 10, P. 25 for a list and explanation of these). What is impressive about the WE DFS is the extras which have been included. It is not possible, or necessary, to document these in full but the following is a summary of the features:

1. An extra utility '*EDIT' is included which is a disc sector editor program. (Uncannily similar in Looks to the one in BEEBUG Vol. 2 No. 3!).
2. A disc formatting program is part of the DFS (i.e. not a file on a utility disc), as 1is a disc verifier. They can be accessed via *FORMnn and *VERIFY commands. An interesting point about the first of these two is that it gives you the option of *FORM80, *FORM40 and *FORM35, (for 80, 40, and 35 track discs , as does the BEEBUG Formatter - BEEBUG Vol. 1 No. 10). You can also ask for a '62 file directory' as opposed to the normal 31 files allowed on the Acorn DFS. (More on this later in the article).
3. Four extra DFS commands exist, *MLOAD, *MRUN, *MOVE and *WORK.

*MLOAD and *MRUN are really utilities for automatically relocating programs which would normally be too big to run on a disc machine (eg. a program which was originally a cassette program).

*MOVE is much the same as *COPY (standard DFS) but gives an extra Level of choice over which files are copied by requesting a yes/no response on all files which match the file specification. In this sense it is similar to *WIPE except that *WIPE s concerned with deleting files, while *MOVE is concerned with copying them. *WORK is very useful in that in enables you to specify a 'work' filename.

After using this command you can simply type eg. SAVE"" , and the DFS will insert the name for you from the *WORK specification. Explicit SAVE and LOAD commands are not affected by *WORK. Also the catalogue listing displays the current *WORK specification.

Two additional '*HELP' messages are supplied and accessed through *HELP FILES, and *HELP SPACE. The first of these will List any open' files - useful for debugging Basic file-handling programs. The second will list all the 'gaps' on a specified disc so that you can see if it is worth compacting it (*COMPACT) in order to gain more storage space.

Many of the drives available on the market are either 40 track or 80 track, it costs you extra if you want to have a 'switchable' unit. The WE DFS goes as far as it can 1in this respect by supplying a *FX110 command which enables you to read a 40 track disc in an 80 track drive.

When formatting a disc the WE DFS will allow you to create a catalogue which can hold 62 file names, rather than the normal 31. When using 80 track drives this is extremely useful as very often you run out of catalogue space before you run out of storage space.

Discs formatted in this way clearly cannot be used properly by other systems but the facility still exists to create 'standard' formatted discs so no practical problems tend to arise.

Watford Electronics have obviously put a lot of work into this DFS and there are certainly some welcome additions to the capabilities of the standard DFS. The cost is comparable to that of a standard disc upgrade and this DFS therefore appears to be good value for money. The one problem with software of this type and scale however is its degree of robustness and lack of bugs. I have not found any real clangers yet and I am assured that all known bugs have been removed. The DFS has worked well for me during its use (though I have not tested all the machine code links and subroutines).