Jeremy Jackson pays tribute to a forgotten pioneer: the Yamaha CX-5 computer
For a professional musician to confess to owning a Yamaha CX-5 computer in 1989 is nothing so terrible; there must be quite a number of the old machines gathering dust in studios (and bedrooms) throughout the land, long since replaced by Ataris, Amigas or even the mighty Yamaha C-1. If that same musician, however, were to boast of still using one almost daily and, in fact, of relying so heavily on this obsolete machine he's acquired another two in case of breakdown... then the howls of derision from aforementioned Atari owners would be deafening! Well, I am that musician and I can shout louder than you can laugh, so be quiet and let me explain my passion for this antique.
For those of you too young to remember - and for those so old their memories are fading - the CX-5 Mk1 was a 64K micro which used MSX basic. The size seems pathetic by today's standards and MSX never really caught on in a British market already dominated by Sinclairs, Commodore 64's and Beebs. On top of that, the CX-5 was pretty heavily overpriced at first, resulting in music stores literally halving the price overnight (which caused severe mental anguish to early buyers like myself).
This apparent disaster of a machine did, however, have one overwhelmingly brilliant feature - the SFG-01
sound module. Hidden underneath the computer (and included in the basic price), this little beast boasted 4 operator FM synthesis, 8-note polyphony, 46 preset voices (some very useful), another 48 user-programmable voices, MIDI and, most remarkable of all at that time, the thing could actually produce eight different voices at once. That's right - if used with the right sequencer program you had an eight voice multi-timbral module years ahead of the competition!
The SFG-01 was replaced soon after by the SFG-05 which had two refinements very important to my plans for using the CX-5 in the way that I still use it now. Firstly, the MIDI spec, was improved to a tolerable level and secondly, the internal software was extended to support the use of a floppy-disk drive with the computer. Yamaha produced an expensive but high quality 780K 3½" disk drive - that's a lot of memory storage for a 64K computer.
My initial purchase also included a miniature keyboard plus two ROM cartridge programs: the YRM101
. The 101 was an 8 track step time sequencer whose main display was a music stave; the 102 was an SFG-01 voice editor showing ADSDR values in bar-graph form. These programs had to be replaced later with disk compatible versions.
I'm sure this brief summary of the hardware and software has left you even more baffled as to how I come to still be using it for anything more useful than propping up a wobbly desk. Well, it was some months before I realised its true potential. Put simply, it is the most perfect almost-all-in-one ON-STAGE 'band-in-a-box', or 'workstation' as they are now called five years later.
Just add any decent drum machine, put the sometimes feeble FM sounds through a chorus, learn to use the step time sequencer PROPERLY and the results can sound extremely professional. What is more, the apparent weaknesses of the system often add to the suitability of the set-up for use on stage.
Consider, for instance, the simplicity of the sequencer program. There are only two modes of operation: Command and Edit.
Saving and loading to and from disk are done on the main screen so loading time between songs is 3 to 5 seconds at the most - and no monitor is required on stage. Furthermore, the 5500 event sequencer, while being capable of handling anything from a 10 minute quickstep medley to Zeps Stairway to Heaven
, actually takes up very little memory on disk. This allows storage of a massive 100 or so songs per disk.
Well, I'm sure you've got the picture by now. Either by luck or good management Yamaha produced a set-up which perfectly satisfied my particular requirements. So, how about your requirements? What use could a CX-5 be to you? Should you buy one? Will it make you a happy and contented person?
For a start, your bank manager should be happier than mine was. That original purchase of computer, keyboard and two ROMs set me back £595 in 1985 but would probably be obtainable secondhand today for around £150. As this is also the most common CX-5 set-up advertised these day, let's see just what it can and can't do from a musical point of view.
If you've so far only produced computer music by manipulating the PSG chip in your micro, then the CX5 has GOT to be an improvement. The built-in SFG-01 sound module is eight-note polyphonic instead of three and the method of synthesis is far more sophisticated and versatile.
Without inserting either of the ROMs, a command of 'Call Music' immediately turns the computer into a 'home keyboard'. You can play two sounds at once (seven note poly plus one lead), generate single-finger chords, add one of the six horrible drum patterns or even Auto Bass Chord Accompaniment - oh, endless seconds of fun! If this is all you intend to use the machine for, a more up-to-date miniature keyboard would sound better (especially one with PCM drum sounds).
Even in this simple form, though, the CX-5 does at least get you into the wonderful world of MIDI - just. You can play an external MIDI sound source from the CX-5 music keyboard but you can't play the SFG-01's sounds from an external MIDI source. This last point is very important as it means the CX-5 Mk1 fitted with its original sound module cannot be used as a MIDI expander. The SFG-01 must be replaced with the SFG-05 before any MIDI in signals are recognised (apart from syncing the sequencer to an external device).
What of the preset voices? As I hinted before, for the pro user they are a little bit 'thin' but respond well to treatment with chorus and reverb. They are, indeed, typical early 4 operator FM sounds as featured on many Yamaha keyboards such as the DX-9 and DX-100. Generally speaking, they don't have the realism of 6 operator DX-7 patches, never mind today's sample based sounds. However, 'not realistic' does not mean 'useless' - some are very handy.
Anyway, if you get bored with the presets you can plug in the YRM-102 FM Voicing Program and create your own brilliant sounds. If you are successful at this, you've probably got a talent for it. If you fail, don't worry, most of us do. I won't attempt any brief explanations of FM synthesis, I'll just say that, in my experience, it is quite easy to alter the basic envelope of a sound but quite another matter to create the tonal characteristics you require. The voicing program itself would benefit from a graphic display of the envelope of each operator. You could, of course, take the easy way out and buy cassettes full of voice data prepared by people cleverer than I. Most banks of sounds contain the usual mixture of good, bad and ugly; there are plenty of tapes still widely available.
I've already expressed my personal satisfaction with the 'Music Composer' sequencer program - it really brings the whole system alive. Perhaps I should also include a few less biased words of warning. Firstly, you need at least a little knowledge of conventional musical notation or you will find it very heavy going. Secondly, even if you are used to working with 'dots', the sequencer is a little slow to program. The process of step time recording is almost the opposite of real time MIDI recording where one plays, then edits and/or quantises. In step time you get it right first time, note by note and use all manner of dynamics, tempo changes, etc., to give the sequence a live feel. The finesse of the finished piece, however, handsomely repays the time and effort involved.
You may also come across several other programs for the CX-5 during your search of the classified ads. There are DX-7 and RX editors, a Music Macro program for using the synth while in Basic and a couple of real time MIDI recordes for use with a CX-5 fitted with the SFG-05.
The Yamaha version of the real time recorder suffered from an unbelievable inability to utilise the computer's onboard sounds, making a second sound module a necessity. To add insult to injury, Yamaha suggest in the manual that a second CX-5 should be acquired for this very purpose! The recorder itself is unsophisticated by today's standards but does feature quantisation and the four tracks in each of four banks can be 'bounced down', mixing different MIDI channels onto a single track.
The other widely available real time recorder was from D.M.S., whose eight track sequencer was able to use the CX-5's sounds. I suspect it was more popular than Yamaha's version (but cost twice as much).
To sum up then, as a cheap basis for a simple MIDI set-up, a secondhand CX-5 is good value, versatile (with the right programs) and expandable via MIDI. It must be remembered, however, that as far as software is concerned, this system is bound to fall further and further behind the times. If you do decide to look for one, you can keep your eyes off mine - I'm definitely not selling!!!
Price: Secondhand price see copy
Supplier: Yamaha, (Contact Details)