Yamaha CX5M
This page was last modified 02:18, 26 July 2018 by Gdx. Based on work by Mars2000you and Rderooy 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 similar to the CX5F but was aimed at the international market. The power supply is external. It is heavy and big. The CX5M is available in several models depending on the country of destination. The model number is marked only on the SN sticker. All keyboards are QWERTY only a few keys sometimes differ, such as the £ key.

Brand Yamaha
Year 1984
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
Extras Module port, FM synthesizer with MIDI IN/OUT connector, music keyboard connector and stereo audio out


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 CX5M
Yamaha CX5M PCB
Yamaha CX5M label
Yamaha CX5M left side
Yamaha CX5M back
Yamaha CX5M right side
Yamaha CX5M computer and power supply
Yamaha CX5M back and left sides
Yamaha CX5M Power Supply


SFG-01 Screen

More info about the SFG modules on these pages:


The CX5M is a MSX1 with addition of 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
Bank C000h~FFFFh RAM Cartridge
Bank 8000h~BFFFh
Bank 4000h~7FFFh Main-ROM
Bank 0000h~3FFFh
  • By default the Module slot contains a SFG-01 from 4000-7FFF (which gets mirrored to 0000-3FFF and 8000-FFFF)


  • RGB output (French model)
  • RF connector (PAL models)
  • Video composite PAL 75Ω (PAL models)
  • Analog sound output (PAL models)
  • Monitor connector with sound video composite signal (CX5MC & CX5MU)
  • Data Recorder connector
  • Centronics compatible Parallel port for a printer
  • 2 general connectors (Joysticks, Mouse, Paddle controllers, etc)
  • 1 cartridge slot
  • 1 module slot (left side, 60 pin connector)
  • 1 expansion bus (back side, 2nd cartridge slot via CA-01 adapter)
  • Music keyboard connector (via SFG-01 module)
  • MIDI IN/OUT (via SFG-01 module)
  • Audio out stereo L/R (via SFG-01 module)


  • 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)