Advanced Computer Products Electron Plus 4

True BBC Micro disc compatibility at last! This little box of tricks will allow you to use any 3.5" or 5.25" disc drive and will handle any Acorn DFS disc.

Originally only the ADFS 3.5" format was available through the Acorn Plus 3. More recently, Solidisk have provided DFS and ADFS compatibility with the Electron Filing System interface. Cumana provide their own DFS and transfer software on disc with their interface. The Plus 4 cuts out the need for such converters.

The physical housing of the Plus 4 is better than the Cumana or Solidisk interface in that it is smaller and feels much more solid in the Plus 1 slot. The cable to discs drive does not have to bend double as on the Cumana design. The Cumana and Plus 4 both have default PAGE settings of &E00 but the Plus 4 lacks the battery backed RAM of the Cumana interface.

With the Plus 4 you can also fit an ADFS chip and have full compatibility with the BBC B+ and Master Series ADFS discs. As a further alternative you could use the ACP Sideways RAM cartridge and load up an image of the ADFS which works just as well. Indeed any 1770 based filing system should plug in and run.

The DFS which is supplied with the Plus 4 is a fairly standard Acorn lookalike. There are some nice touches however, such as an extra parameter with the FORMAT command to allow automatic formatting of two sides of a disc. If you fit the Advanced Disc Toolkit into the spare socket then you are in total command of any filing system you care to install. An ideal combination.

In conclusion, the Plus 4 is a very neat and well built interface which will best serve the needs of anyone wanting to upgrade to discs. The full BBC compatibility is more than just a bonus since a healthy percentage of BBC BASIC and even machine code programs will run on the Electron Plus 4. Anything written for BBC Micro Model B with DFS, even in Mode 7, stands a good chance of transferring to an Electron with PAGE set at &E00. This setting will also aid and abet the transfer of tape-based software, an important point in these days of tape-only games houses and handsome collections of Electron games software.

The Plus 4 costs £79.98. Details from ACP on 0276 76545 or from Advanced Computer Products, 6 Ava House, High Street, Chobham, Surrey GU24 8LZ.

Slogger ROM Box Plus

Another Plus for the Electron owner to consider. Slogger's provides two cartridge slots, four sideways ROM/RAM sockets and a centronics printer port and is plainly aimed at the Electron being asked to perform serious computer applications.

The ROMbox Plus is not very pretty to look at. Compared with the Plus 1 expansion box it looks quite rough with no dust flaps covering the cartridge slots. The idea of ROM sockets with no covering has always looked cheap to me although BBC owners often expose a lot of bare circuit board to the elements without a qualm. The box itself is a beige colour which doesn't match the cream colour of the Electron - the same colour as the original ROM box in fact.

The ROMbox is easy to fit onto the back of your Elk or Plus 3 and feels safe enough although it is not half as sturdy as the Plus 1. At the rear all alone is the serial printer port. There is no analogue to digital port as on the Plus 1 but to make up for its absence there are the four ROM sockets which can be used for RAM if required. The supplied instructions are clear and comprehensive though not very robustly presented. The features of the ROMbox, full fitting instructions, link settings and technical details are supplied. The links on the top of the box determine the use of the sockets.

The first thing I tried to do was to fit my Cumana disc interface to see if it worked with the box. But, try as I might, I could not get the interface edge connector to fit in the cartridge slot. It was very slightly too long!!!

Next I tried the Advanced Computer Products Plus 4 which both fitted and worked perfectly, as did the A.C.P. Sideways RAM cartridge. As for Acorn compatibility, the ROMbox Plus did not interfere at all with the Plus 3. I made good use of the ROM slots to convert tape software to disc with the T2P3 ROM, also by Slogger. The results were very pleasing (a high percentage and some surprise successes) as were those of using Acornsoft's View and Viewsheet ROM cartridges, both of which worked as if on the Plus 1. The ROM slots which can also handle RAM are useful for holding ROM images.

A further use for sideways RAM and an advantage over the Plus 1 is the ability to use an 8K RAM chip (or 2 8K chips on a card) as a printer buffer. The buffer software is built into the onboard EPROM and provides commands *BUFFER, *BUFFER ON, *BUFFER OFF, *BUFFER FLUSH, *BUFFER PAUSE and *BUFFER RESUME. This is a welcome addition to the software and means that long listings and text files can be quickly dispensed to the printer and other tasks begun.

Using a printer is very easy once it has been configured for use as on the BBC Micro. One suggestion is that Slogger should supply their excellent Printer Driver documentation with the ROMbox Plus so that printer owners can get going with style codes and effects straight away without struggling with the usual supplied manuals. The uses of a printer are countless and I highly recommend all Elk owners to consider purchasing one if they haven't already done so. With the ROMbox Plus and printer setup I was able to use all the wordprocessors and screen dumps as supplied through A&B Computing's Software Sale and of course business type applications such as Starword and Starstore II require a printer to be truly useful.

Overall the ROMbox Plus is an extremely useful addition to your Elk and a worthy alternative to the Plus 1. It's an effective interface to all sorts of add-on equipment. My only gripe is that the box is not very strong and the cartridges are hard to insert and remove (my Cumana interface being *impossible* to fit).

The ROMbox Plus costs £69.95. Details available from Slogger on 0634 52303 or from Slogger Ltd, 107 Richmond Road, Gillingham, Kent.

Matthew FifieldMark Webb