Beginner's Guide To The Electron 1

By Chris Chadwick

Originally published in EUG #05

Hardware Addon Heaven

This article is aimed at the newcomer to the Electron. If you are vaguely aware that the Elk can be expanded but are confused by the variety of addons available then this is for you. Old hands may learn nothing new.

What I shall do is explain the basic machine connections, suggest some maintenance and summarise the main improvements on offer. I then give a sample of what these are.

The Electron is a simple beast with tremendous potential for improvement via an array of sockets and plugs. Some are more obvious than others, e.g. the one marked "CASSETTE", but "VIDEO" does not connect to the VCR under the telly! In fact, "VIDEO" is a monochrome version of "RGB" (Red, Green, Blue). Both allow the connection of a specialised monitor which is better than an ordinary television, especially for Word Processing (WP), but is of doubtful benefit for the basic Electron beyond making it independent of the household goggle-box.

Keep It Clean!

If your Elk is secondhand, think about cleaning it inside and out. Too much dust can cause breakdowns! If you're confident about taking the lid off your computer do so but if you're unsure about what you are doing, don't!

Once you've removed the fastening screws from the underside of the machine, gently ease the keyboard connecting strip away from the socket, to leave your Elk in two pieces. Disassemble the computer as far as you are confident and dust with a clean, dry paint brush. The case and keytops can be effectively cleaned using a damp cloth and a drop of washing up liquid.

Disconnect from the mains first!!!

Do not plug/unplug needlessly and never when the machine is switched on! The sockets can wear out, especially the power plug.

Tape Troubles

The next thing you can do for your Elk is get a good cassette recorder to use with it. 'Good' in this case means a mains/portable mono deck with a socket for remote motor control, preferably a 'data' mode and a speaker on/off switch. [The Sony TCM-818 is worth investing in - Will]

Walkpersons and ghetto blasters are rarely up to the task, particularly in the area of automatic motor control which is invaluable when loading multi-file programs with a lot of on-screen instructions. Try loading Superior's Vertigo using a deck without a REM socket!

Interfaces

An interface is necessary for nearly every improvement which can be made to an Electron. There are two main 'bolt-on' interface options: the Pres Advanced Plus 1 (AP1) and the Slogger Rombox+, as well as a cheaper, cutdown version from Software Bargains. A Plus 1 or Rombox is a doddle to fit: push it gently over the connecting strip at the back of the Electron and fix it with the bolts provided. There is it - done, increasing the physical size of the Elk by about half as much again.

Plus 1 Or Rombox?

The Advanced Plus 1 from Pres has the following as standard: Two slots for installing cartridge-based software and hardware such as the Acornsoft View family and disk interfaces. There is a socket to connect an Epson-compatible printer and an ADC port (Analogue to Digital Converter) for joysticks and a host of 'serious' applications. The unit has a cream-coloured case to match the Elk. Please note the distinction between an Advanced Plus 1 and the original Plus 1 produced by Acorn.

The Slogger Rombox+ has four ROM/RAM chip sockets and two cartridge slots like those on the AP1. There is also a printer port. Slogger have a cartridge slot interface for using 'Atari-style' switched joysticks, available separately. Again, please note the distinction between the original Slogger Rombox which was basically a holder for eight ROMs, and the later Rombox+.

Also note that the Pres AP1 is purpose-built to accept an upgrade for mounting ROM/RAM chips.

Software Bargains' Lindy Board

The Lindy interface from Software Bargains has two cartridge slots and a printer port, with View and Viewsheet ROM cartridges included in the price and it seems very competitive. However it is handicapped by not being cased, leaving it wide open to damage. There is no joystick port and it does not support ROM sockets in any form. Nevertheless, it will support a disk interface and is ideal for anyone needing a cheap route to a WP-only machine.

ROMs Vs. ROM Cartridges

ROM cartridges differ from ROMs in that they may be easily exchanged in their slot with much less risk of damaging the machine or cartridge. Slogger and Pres can both supply replacement Operating ROMs that provide additional disk and ROM management "Star" (*) commands that are indispensible for the expanded Electron.

The Pres Advanced Plus 2 (AP2) ROM reduces dependency on the Utilities Disk for ADFS users, while the Slogger Expansion ROM 2.0 is an equally good improvement for DFS/Pegasus users. Both Operating ROMs provide further support for their suppliers' products and general use. You may find that they already fit the replacement Operating ROM to their unit or offer a special deal when buying them together.

Expanding Your Machine's Memory

There is only one convincing way to get a bigger and faster Elk, and that is with the Slogger Master RAM Board (MRB), the so-called "64K Electron". The MRB has three states: Normal (as you are), Turbo; for extra processing speed and 64K; which doubles the onboard RAM - vastly increasing the space available for all screen modes. A switch is fitted at the side of the Elk to change states, which can be done freely while the machine is on, although the memory is cleared. A less obvious but still useful tip is that you can load up in any screen mode while in 64K or in Turbo mode. Amongst upgrades for the Elk, the MRB is unique in that it doesn't first require another interface to be fitted.

The 64K is in effect a co-processor and has no value in arcade games but makes many text adventure games intended for use with a BBC available to the Elk. An MRB can be configured as Sideways RAM (SWR), used as a printer buffer or for editing two programs at once. The Turbo option is a joy for the dedicated games player. The days of arthritic arcade action are banished as real speed is brought to your favourite games! It can make some games too fast to be enjoyable (Snapper especially!) but others (e.g. Repton, Elite, etc) really benefit from the extra 'umph' under the lid, and BBC games that are otherwise too slow to be fun can become playable. The 64K comes into its own for WP by hugely increasing the processing speed as well as the available memory (eg View Mode 3 jumps from 12542 to 28926 bytes free!) so you no longer have to wait for the screen to catch up with your lightening typing!

As the MRB can be switched off and the Elk returned to its native state, there are no disadvantages which cannot be overcome. This is useful because a few games will not work with the MRB, but very few. For programming or WP the MRB is only advantageous to the Electron user. One great advantage of a bigger memory is the disguise it provides for the memory grabbing Advanced Disc Filing System (ADFS) which can be a severe problem for the standard Electron.

Go Disk!

A disk system has real advantage over tape in terms of reliability, ease of use and speed of loading and saving, especially for long programs and large files.

The main confusion with disk is in the type of filing systems and disk sizes available. Unfortunately there is no such thing as a standard Electron Disk System.

ADFS (Advanced Disc Filing System) is the Acorn-preferred system used in the Plus 3 (Long out of production) and on all Acorn computers (including the Archimedes) except the BBC. The Beeb was supplied with a distincty old tech DFS (Disc Filing System) using 5.25".

ADFS is the more efficient of the two, making greater use of disk space by permitting the creation of multiple directories (A group of files or programs), and has much in common with MS-DOS the industry standard PC Disk Operating System.

DFS allows only one directory with a fixed number of files. If these files are rather small, the rest of the disk will be left unused. Moreover DFS writes to the disk in such a way as to make it difficult to extend the size of a file once a subsequent file has been written. However DFS takes no memory and is an easy system to manage and understand. ADFS grabs 3.5K of memory for its own work space. This can be critical in 32K or Turbo mode, for games play or word processing. Pres can supply a version of the system which keeps PAGE at &E00, returning that valuable 3.5K of RAM to the user.

The Acorn Plus 3 has been superseded by the much improved Pres AP3, using an uprated Acorn ADFS. Available for those wanting BBC compatible DFS is the Pres AP4. The Slogger Pegasus 400 system is a much improved DFS, being highly efficient with the disk space, and has extra star (*) commands not found with standard DFS. These are the only Electron Disk Systems currently available, all using a cartridge slot mounted interface.

And Finally...

It is possible to have both systems mounted in the one interface, which is desirable if memory space is important to you, 3.5K makes a largish hole in 64K as well as 32K! Given the plethora of choice, the only thing to do is weigh up the benefits and failings of each and then buy what you want, both systems perform perfectly well after all. I have always found both suppliers willing to answer my questions, no matter how stupid I thought they were (The questions I mean!) and are the best people to answer your interest in and uncertainties about their product.

Christopher Chadwick, EUG #5