Yamaha CX5M
This page was last modified 16:22, 16 December 2021 by Mars2000you. Based on work by Rderooy and NYYRIKKI and others.




The Yamaha CX5, CX5F, CX5M, CX5MII and CX5MII/128 computers were specifically targeted at music and sound production, and as such were regarded by many as non-standard MSX machines. However, they are in fact standard MSX1 computers and can be used as such.

The CX5M is based on the Japanese CX5F but was aimed at the international market. For most regional variations, the power supply is a big and heavy external unit, the NP 55xxx. The exception to this are the CX5MC and CX5MU which have an internal 120V power supply.

The CX5M is available in several models depending on the country of destination. The model version is marked only on the underside sticker. All keyboards are QWERTY and include a dead key to produce accents. Only a few keys sometimes differ, such as the £ key (not available on CX5MC and CX5MU). The variations are as follows:

Product Region PSU VDP Video Out Keyboard
CX5MA AU, NZ Yamaha NP 55150 TMS9929A RF, Composite Audio and Video QWERTY with £ key
CX5MC CA Internal 120V 60Hz TMS9918A Monitor Connector QWERTY
CX5ME UK Yamaha NP 55140 TMS9929A RF, Composite Audio and Video QWERTY with £ key
CX5MF FR Yamaha NP 55170 TMS9929A RGB QWERTY with £ key
CX5MG DE Yamaha NP 55180 TMS9929A RF, Composite Audio and Video QWERTY with £ key
CX5MS Scandinavia Yamaha NP 55130 TMS9929A RF, Composite Audio and Video QWERTY with £ key
CX5MU US Internal 120V 60Hz TMS9918A Monitor Connector QWERTY

Brand Yamaha
Year 1984
Region Australia, Canada, France, Germany, New Zealand, Scandinavia, United Kingdom, United States
Launch price DE: 1498 DM, FI: 4950 FIM
RAM 32kB in slot 0
Media MSX cartridges, side slot modules
Video Texas Instruments TMS9929A or TMS9918A (CX5MC & CX5MU)
Audio PSG (YM2149), SFG, MIDI
Chipset Yamaha YM5214
Keyboard layout QWERTY with some variations (see table above)
Extras 60 pin module port, FM synthesizer with MIDI IN/OUT connector, music keyboard connector and stereo audio out
Emulation ROMs dumped and emulated for the CX5ME version. The rear expansion slot and side module slot are handled like regular MSX cartridge slots. ROM dumps needed for the other versions. See this thread for details


The CX5M is identical to the Yamaha YIS-503, but was sold with a built-in FM synthesizer module SFG-01 plugged into side slot with MIDI IN and OUT. There is also an updated version called the SFG-05, sold separately or included with the CX5MII. From BASIC, the music firmware can be launched with CALL MUSIC or _MUSIC.



Yamaha CX5MF (with £ key)
Yamaha CX5MF underside
Yamaha CX5MU with box
Yamaha CX5M PCB
Yamaha CX5MU label
Yamaha CX5M left side
Yamaha CX5MA/E/G/S back
Yamaha CX5MF back
Yamaha CX5M + power supply
Yamaha CX5M right side
Yamaha CX5M box
Yamaha CX5M English manuals
Yamaha CX5M French manuals


SFG-01 Screen

More info about the SFG modules on these pages:


The CX5M is a MSX1 with a Z80A from Sharp (LH-0080A) and a side slot, reserved for the SFG-01 or SFG-05 module. The sound modules are 8 note polyphonic 4-op FM synthesizers by Yamaha, based on the YM2151 OPM sound chip (YM2164 in the SFG-05, which is compatible). They can be used in other MSX computers via the UCN-01 side-slot to standard MSX cartridge slot adapter.

The CX5M can be used together with the Yamaha YK-01, YK-10 and YK-20 keyboards for use with the FM synthesizer. The Toshiba HX-MU901 is also compatible.

To use the extension bus as second cartridge slot, you need the Yamaha Single Cartridge Adapter CA-01.

To get 64kB RAM with the CX5M, you can insert the URM-01 cartridge in slot 1 or 2 or the SRE-01 module in side slot 3. It means that the 64kB RAM is split between two slots, a configuration that can cause poorly written software to crash. Also, with this layout, the POKE-1,(15-PEEK(-1)\16)*17 trick to workaround buggy software that does not handle subslots properly will not work on this machine expanded to 64kB RAM in such a way. A better solution is to get a 64kB RAM cartridge or a memory mapper cartridge that can self-initialise on MSX1.

Slot Map

Slot 0 Slot 1 Slot 2 Slot 3
Page C000h~FFFFh RAM Cartridge
Page 8000h~BFFFh
Page 4000h~7FFFh Main-ROM
Page 0000h~3FFFh
  • By default the Module slot contains a SFG-01 from 4000-7FFF (which gets mirrored to 0000-3FFF and 8000-FFFF)



  • CX5MA: Australian and New Zealand's market (RF = PAL-B on VHF 3/4ch)
  • CX5MC: Canadian market (RF = NTSC on VHF 3/4ch - needs the RF-02 adapter)
  • CX5ME: United Kingdom's market (RF = PAL-I on UHF 36ch)
  • CX5MF: French market (Only RGB output)
  • CX5MG: German market (RF = PAL-G on UHF 36ch)
  • CX5MS: Scandinavian market (RF = PAL-G on UHF 36ch)
  • CX5MU: United States market (RF = NTSC on VHF 3/4ch - needs the RF-02 adapter)