Jon Bates was out doing his Christmas shopping when he popped into his local branch of Boots. What should he see, but Cheetah’s latest Keyboard and MIDI add-on? Cheetah hadn’t sent him the goodies, so a quick chat to the Boots Manager led to a review...


For the first time ever, a computer-based firm has stepped out boldly into the territory of the music business. In short Cheetah, under commission from Boots, have launched what is known in the trade as a ‘mother’ keyboard. On its own it’s as deaf and dumb as a stuffed dodo, but linked via MIDI to either a synth, synth module or MIDI hardware, it acts as a polyphonic master controller of all and sundry — especially those synths equipped with fiddly little keys. The instruction manual is very easy to understand with jolly diagrams of the various configurations that can be achieved with the keyboard and various add-ons. I will assume that you have a little knowledge of MIDI by now as I have been bleating about its virtues for some time (see — you should have been paying attention!)

The MK5 is a five octave keyboard with full-size keys and transmits MIDI codes. Obviously it transmits note on/off, but by selecting the centrally-positioned program mode button, the top octave takes on various other functions: channel up/down, octave up/down and program up/down — programs here meaning the sound programs banked in the synths — all 128 of them. A red LED, positioned to the right of the keyboard, flickers ominously whenever a note is played. From this the channel, program, and octave number are read off. Endless sustain (more correctly, a hold function) is achieved by pressing the mode button before releasing the notes.

The pitch-bend wheel is rather oddly positioned — above the keyboard and parallel to it. I’m not sure that this is a good thing: no other keyboard manufactured since 1971 has done this. It’s almost as if it were an afterthought. Another problem is that it only bends half the value which the synth is set to.

As with most products, Cheetah have had to suffer the problem of how much they can include in the MK5 without raising the price too high. Much of the MIDI protocol is not here: keyboard split, modulation wheel, transposition, tuning, provision for sound layering and velocity sensing are all absent. A more serious omission is that it does not work in omni mode — transmitting on all sixteen channels simultaneously. This means that you are rather stuck when it comes to using two or more modules as you can only address them individually or by re-assigning each synth’s receiving MIDI channel. Perhaps an intelligent add-on box could provide multiple patch (program) memories and far more detailed MIDI data instructions. (Many thanks to the management and staff of Boots in Stourbridge, who loaned us their one and only MK5 for the purposes of this review. Mass executions have since taken place in Cheetah’s promotions department as a result of their grave oversight.)


The MIDI interface from Cheetah has still only appeared in prototype form — there is however a MINI interface. This is an extra for the MK5 keyboard, but it is essential if you have a 128 but no synth. It gives you control over the AY 8912 chip in the 128 which, it must be admitted, was really designed with arcade games in mind; only giving you a basic square wave. Plugging in the hardware and loading up the Microdrive-compatible software gives you full control over the chip: sound shaping, pitch shaping, noise mixing and a split keyboard function. The menu appears as pop-up overlays on the screen you are working on and is very easy to use.

Full marks for the graphic display of the sound/volume shaping section (more properly called an envelope). It gives a pretty good idea of what the sound will be, although the sustain part of the envelope seems to have a fixed duration. It’s also a doddle to work with. Not so the pitch envelope, which is far more complex and requires you to fill out an eight stage table of up to 24 numbers per sound. Why not simplify things and display it visually?

The ‘noise’ is optional and can be mixed in with the main sound or heard on its own. It isn’t wonderfully clear from the manual, but the noise is also shaped by the volume envelope. There is also a modulation option which allows the noise to be affected by the pitch envelope: a different sort of ‘swoosh’ sounds depending on which part of the keyboard you are playing.

The keyboard split is a goodie. Although the chip is only capable of playing three notes simultaneously, these can be split so that the bottom two octaves of the keyboard can play a different sound to the upper part, a useful and very sensible function. The pitch bend on/off is really a non-starter as: a) you’d hardly fiddle around with the pitch bend control if you didn’t want to use it so why bother to switch it off and b) doesn’t track with the key scaling — in other words it only bends a fraction of an octave at the bottom end but achieves a full octave of bend at the top.

There is a tremolo option which does a fair job of chopping the sound up, plus a sound file which can contain up to 64 sounds — you get 20 when you purchase the module. Sounds can be called up from the Spectrum or from the MK5 keyboard — very efficient. The big complaint here is that none of the sounds can be labelled, they are known by numbers only. I can see this as a real pain when you have created various sound files and need to remember what voice is what from file to file. Also a file merge would be nice so that voices on one file could be added to another.

Given the limitations of the AY 9812 chip, Cheetah have done a fine job with this module. I’m not sure that it justifies its price tag — particularly as I could not get mine to work with any other MIDI keyboard other than the MK5 (I suspect some mix-up of MIDI codes and flags). It is however a fascinating and easy tool to use. Watch this space for details of their next load of music modules — it would seem that Cheetah are becoming very motivated in this direction.

Both these products are available from most branches of Boots. The MK5 will set you back £99.95 complete with power supply, and the MINI interface £29.95.