Computer Music Chronicles, The 80's: CX5M pt.1

Look, I have a sickness ok? Old Computers, especially old music computers, tickle my nostalgia gland like nothing else! It seems every month I'm buying some bit of old sonic tat...propelled forwards by a love of retro aesthetics & quirky sound generation.

1984's CX5M has it all; the sleek black & teal Yamaha livery, internal 4OP FM soundchip (akin to an FB01), chunky cartridges(!) and compatibility with the MSX home computer standard - meaning I may be able to blast some aliens in-between sound design sessions!

RMC's look at the (slightly later) CX5MII is a good first port of call for anyone interested in this system. Of course, I'm sure I'll make my own video eventually, feeding it MIDI & evoking clangorous FM tones.

Now, I'm very much still a n00b at this, but I thought I'd share some of the things I've learned in my short time as a CX5M enthusiast.

• SFG Matters - there's an "SFG" unit underneath the computer which houses the FM gubbins, MIDI & audio ports - earlier CX5M models shipped with the SFG-01 and this version can sadly only use the MIDI ports for SYSEX data. A later SFG-05 model had full MIDI IO, letting you drive the CX5M from any MIDI device. Modifications exist to upgrade the 01 to full 05 spec, but I haven't looked too deeply into this.
• MSX limitations - the CX5M is an MSX1 class device with 32K RAM. This means, outside of Yamaha's own functionality, you'll be limited to the earliest & most primitive MSX games - none of those later MSX2 classics. Mapper carts like this can expand the memory, but MSX2 compatibility? No way! The Japan-exclusive CX7M is a full MSX2 machine and very lovely indeed, if you can find one! Back in blighty, the CX5MII/128 is almost MSX2-compatible - requiring some modification to the machine, but probably your best bet.
• Software requirements - So, with no cartridge inserted, you may type CALL MUSIC & obtain a charming UI that permits you to choose from 48 preset instruments, split the keyboard 4 ways, call up a backing rhythm and even adjust basic sound parameters like volume, vibrato or tremolo - fun for all the family! However, in order to sequence a song, edit your own FM presets or even use those sounds within a BASIC program, you'll need an array of software cartridges. Available titles include:

YRM-101 FM Music Composer (Notation-style sequencer)
YRM-102 FM Voicing Program
YRM-103 DX7 Voicing Program
YRM-104 Music Macro (Use FM sounds within a BASIC program)
YRM-105 DX9 Voicing Program
YRM-301 MIDI Recorder
YRM-302 RX Editor
YRM-303 MIDI Macro & Monitor
YRM-304 DX7 Voicing Program II
YRM-305 DX21 Voicing Program
YRM-501 FM Music Composer II
YRM-502 FM Voicing Program II
YRM-504 Music Macro II
YRM-506 FB-01 Voicing Program

Gotta catch 'em all! Anyhow, please excuse me as my YRM-502 cartridge has just arrived and I need to go twang something. Thanks for reading this article, I'll continue onto pt.2 once I feel my knowledge level has increased. In the meantime, I'll leave you with a few more interesting videos:

Posted by MagicalSynthAdventure an expert in synthesis technology from last Century and Amiga enthusiast.

Yamaha Social

• New Yamaha PSR-SX620 Arranger Workstation 21-Aug-26
• GearExpo UK 2026: Yamaha MGX16V Digital Mixer With HDMI Audio Embed 28-Jun-26
• Yamaha Launches Creator Pass 12-Mar-26
• Yamaha MODX M Has More Of Everything 15-Oct-25
• A Track Made With The Ultra Rare Yamaha VP-1 04-Aug-25