Guess what, there is one language that can be used for all computer software.

It's called MONEY.

To those of us whose most frequent meetings with microprocessors involve feeding our cashpoint card to a slot in a wall, the cost of software is even more confusing than the intricacies of its construction. How is it that in the same issue we have the Island Logic System going for £25 and the UMI-1B for £495?

They're both music systems, they both allow you to compose material, they're both dedicated to the fabulous BBC B micro and neither contain any purpose built synth circuitry à la Yamaha CX5. (The Island Logic program steals from the BBC's beep-boop games noises — but we'll let Honeybone explain that.)

Briefly explained, the UMI-1B is an elegant, luxurious hi-fi set against the IL's Stowaway. And this is how it works...

Firstly, the UMI, developed for the London Rock Shop by Lynton Naiff, is for professional musical applications — for musicians buying computers to aid their music, not computer owners stumbling on a musical offshoot for their existing micro.

It's MIDI based, obviously, but designed with certain reservations in mind about the abilities of MIDI to handle a lot of polyphonic information with enough speed. It currently operates around the Yamaha DX7 storing 16 tracks each capable of 16 note polyphony. They can be programmed monophonically or polyphonically, in step time or real time, directly from the DX7 keyboard. UMI will also remember pitch bend, wheel modulation, velocity and second touch information — in other words, everything involved in a performance including voice changes within a track.

And, thankfully, MIDI is not God. UMI can be run from an external clock at a choice of 24 (Drumulator, Roland, Simmons, Sequential, Yamaha), 48 (Linn LM1), or 96 (Oberheim) pulses per beat. Finally, distributors Soft Rock Systems Ltd, have borrowed from NASA technology by including the latest, semi-intelligent, user-interactive device — a knob. Turn it one way (to the right) and the sequencer runs faster, turn it the other way and it runs slower. Brilliant. We predict many other computer engineers will rapidly abandon the normal 84 Qwerty instructions required for this obviously highly complex procedure. Thank the maker that someone out there still knows how a musician's mind works.

Your outlay of £495 gets you more than a disk full of smart ideas. An Aries 20K RAM expansion board from Cambridge Computer Consultants piggybacks onto the main BBC board so there's still plenty of memory left for composing after the program has taken its shares. There ought to be enough for 6,500 notes but that's not a true representation of how long songs can be as there are many space saving repeat and chain functions. UMI's MIDI interface box carries sockets for metronome out, sync to and from tape, clock in/out, start/stop, two MIDI outs and a MIDI in plus an RS232-type computer expansion socket and a Roland 24 pulse Din sync socket.

It speaks its mind to the BBC via a 34 way cable connecting to the 1MHz bus socket beneath the computer. The main program is held in what is intriguingly called sideways ROM — chips fitted inside the BBC that make it easy to swap instantly to the computer's normal operations for functions such as word processing or games playing. In other words, you don't have to sit there while a cassette player whirs for 20 minutes.

For those unfamiliar with the Beeb, there are nine red keys in the top left of the Qwerty keyboard which can be dedicated to particular functions and its these that do most of the work on UMI once the system's powered up. The software makes neat, clear and attractive use of the BBC's extensive colour capabilities, and anyone who goes 'bah... gimmicks' at this point has never tried to understand a screen full of semi-identical green numbers after three hours of programming. You're usually prompted helpfully by the screen to carry out the next job.

Initially you're confronted with a menu of the UMI's operations including real time recording, editing and 'pac' modes, more of which later. In the bottom right is a panel of default values for the clock-in rate, metronome click, pattern length (say eight beats for two bars of 4/4), metronome count-in (how many clicks you want to hear before recording starts), and storage whether on disc or cassette. All can be altered using the up, down and sideways cursor keys.

Function description could stretch on forever, so let's go straight into recording in step time, polyphonically, not dissimilar from how you might construct a song chain on a drum machine.

You're immediately faced with five columns of blue letters that, on inspection, turn out to be the D to C semitones of a complete octave. You stroll to the keyboard, press your first chord and the notes you've chosen will turn white on the screen — magic. Now is your chance to alter key velocity info by selecting a value between 1 and 127 as well as the gate length of the note which is simplified to normal, short and very short (75, 30 and 10 per cent of full). Then hit the return key and that beat's worth of notes will have been written. Chords can be built note by note or individual notes deleted (turned blue again) by hitting that key once more. Nothing is entered until the return key is pressed, rests can also be slotted in, and you can step through your pattern using one of the tap keys on the UMI box and each beat's notes will be displayed. At this point they can be deleted, but no new ones inserted which is a slight hitch.

You can edit in pitch bend and modulation info but that's perhaps better done when we're up to real time inputing. We'll finish step time with song construction which is a matter of selecting one of the 16 tracks A to P, and producing a list of the patterns you want played, in the order desired. Typing 1 (return), 2 (return), 4 (return), 4 (return) will play patterns 1, 2, and then 4 twice. Typing 2,2 (return) will play pattern 2 transposed up by two semitones. (Transposing equally downwards requires the strange but unathletic mental arithmetic of subtracting 2 from 256 and typing 2,254.)

At this level of use UMI is a simple compilation program that spiels out the song in four columns across the screen. A lot of the time, good composition is about crude repetition made graceful — and UMI operates well in this area. Certain chunks of patterns can be looped endlessly (for fades), repeated a certain number of times, particular patterns may be played only the first time through and skipped for the repeats, or the song may break away at one pattern and be instructed to 'go to' another further down the list. Here's where you save the space that makes that 6,500 note prediction a paltry estimate.

But enough, most software as sold by Siel and Jellinghaus, can cope with step time. It's real time that's the test of good programmers. Press key F8, stroll to the DX7 and...

You play to UMI's metronome and once you've filled the selected number of measures the pattern will automatically be played back to you for instant assessment. You won't be able to record any more at this point, but be careful with the last note of the bar — it will wrap around to the start of the pattern if you don't keep your fingering tidy.

Every part of your performance will be stored by the Beeb — slides, mod, vicious attacks on the keys, etc. This is one of the qualities that makes UMI unusual, professional, immensely expressive and big on memory. Had you been looking over the hack's shoulder during the review you would have seen a screen readout hurtling through the bytes lugging the amount used. One, two bar, monophonic example with a couple of bends and mods got through 1123 bytes. A lot of this is caused through what the more advanced programmers know as 'unnecessary shit' being pumped down the line. Some of those 1123 bytes can be sieved out and used elsewhere without altering the final result.

To this end there are two pac (compaction) keys. Each time they are pressed, some of the unessential memory will be shaved away and you can listen to the result or retrieve the original for comparison. Pac too far and your smooth pitch bend will start to grow chromatic lumps (actually sounded very imaginative when we did it). Eventually, with no loss of definition, that mono line was packed from 1123 bytes to 205. I'd say that was excellent.

If your timing is sloppy an auto-correct key will pull it in line, usually acceptably but occasionally with quirky results. Remember, it's not just dealing with timing information as on a drum machine's auto correct, but also with pitch, note duration and maybe mod as well. You can retrieve the original if you don't like the auto-corrected version.

While listening to the first take you can overdub extra material up to the 16 note polyphonic limit of the DX7 but nothing happens to the first recording until you press C for commit. Maximum pattern length is 64 beats and again you can step through the sequence deleting notes but not inserting any; you'd have to wipe the pattern and start again. This I see as the only real shortcoming in an otherwise exceptional system — since you are recording in reasonably short chunks, it's perhaps excusable.

Otherwise it's fine detail. It would be convenient if you could also step backwards through the pattern, and I personally like metronomes that change tone when they swap from count-in to recording so you're not left wondering if you came in a beat too late. But as Shakespeare said 'There are more things in heaven and earth than are dreamt of in your software, Horse face'. Or something like that.

Patterns or parts of them can be copied from anywhere to anywhere. One example the 22 page English manual (that's English as opposed to jargonese) gives is that you could copy a bass line into another channel, give the channel a separate MIDI assignment and so have the bass line double by another 'instrument' at particular points of the song. Songs are naturally dumpable to disk.

All of this may not help too much if you've got what the manual refers to as 'lazy' sounds — string voices with slow attacks that take a split second to get going and therefore appear to throw out the timing. To pull them forward you can inject a fine adjust bar — one that might be given only 188 pulses in a bar of 4/4 in place of the standard 192 for the 48 pulse/beat clock.

However, has all this explained why the UMI-1B clocks in (sorry) at £495? Well, if you've spent close to £1500 on a keyboard that lets you express your music with pitch bend, modulation, key velocity and second touch, do you now want to spend £70 on a slice of software that ignores all of it? As we said some months ago, the final judgement on music software should be made on the first word, not the second. When I heard a demo of the UMI I thought it was a person playing, not a computer. It was. It was the musician who had written that song and got the computer to remember it for him... not the other way around. Sufficient said.

UMI-1B
BBC B music software: £495