I have the main unit, Yamaha Unit connector UCN-01, Yamaha Floppydisk interface
FD-051, Yamaha floppydisk FD-05 and MSX Academy slot expander.
type computer
country Japan
year 1986
os ROM Microsoft Extended Basic (MSX Basic V1.0)
cpu Zilog Z80
speed 3.58 MHz
ram 128 KB
rom 32 kb BASIC/BIOS
graphic 256 x 192, 32 sprites
colors 16
sound General Instruments AY-3-8910, 3 channels, 8 octaves
ports Two cartridge slots, printer, tape, Sound output, Video composite output,
Video RF Built-in synthesizer, piano keyboard connector, MIDI o/i,
Stereo audio output, Printer, bus, joystic, floppy, monitor,
stereo jack output
The Yamaha CX5MII/128 — The Music Computer
The Yamaha CX5MII/128 was a second-generation version of Yamaha’s remarkable CX5M — an MSX computer with built-in FM sound synthesis hardware that transformed it into a genuine professional music workstation. While other MSX computers used the standard AY-3-8910 sound chip for three-channel audio, the CX5M series incorporated Yamaha’s own YM2151 FM synthesis chip — the same chip used in Yamaha’s professional FM synthesisers and arcade game sound hardware — giving it audio capabilities that were genuinely extraordinary for a home computer of the era. The CX5MII added 128 KB of RAM over the original CX5M’s 64 KB.
FM Synthesis — Professional Audio in a Home Computer
Yamaha’s FM (Frequency Modulation) synthesis technology, developed by engineer John Chowning at Stanford University and licensed by Yamaha, produced complex, rich sounds that analogue synthesis could not easily replicate. The Yamaha DX7 synthesiser (1983) had revolutionised professional music production with FM synthesis, and the CX5M brought the same FM synthesis hardware into a home computer — making professional-quality music production accessible to amateur musicians and students at a fraction of the cost of dedicated hardware synthesisers.
Music Software
The CX5M’s music capabilities were supported by dedicated software including FM Voice Editor (for programming FM synthesis sounds), Music Macro Language tools, and various sequencer applications that allowed composers to create multi-track music using the FM synthesis hardware. Yamaha positioned the CX5M explicitly as a music education and production tool, and it found a dedicated following among musicians who appreciated having professional FM synthesis capability integrated into a general-purpose computer.
A Unique Instrument
The Yamaha CX5MII/128 occupies a unique position at the intersection of computing and musical instrument history — a machine that was simultaneously a fully compliant MSX computer (running all MSX software) and a genuine musical instrument with professional FM synthesis capability. It represents Yamaha’s vision of convergence between computing and music production that anticipates the digital audio workstations that would become central to music production in the 1990s and beyond.