Yamaha CX5F
This page was last modified 15:08, 16 December 2021 by Mars2000you. Based on work by Gdx 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 CX5F is similar to the CX5M but was aimed at the Japanese market and features a Japanese keyboard. The power supply is internal.

Brand Yamaha
Model CX5F
Year 1984
Region Japan
Launch price ¥64,800
RAM 32kB in slot 0
Media MSX cartridges, side slot modules
Video Texas Instruments TMS9928ANL
Audio PSG (YM2149), SFG, MIDI
Chipset Yamaha YM5214
Keyboard layout QWERTY/JP50on
Extras 60 pin module port, FM synthesizer with MIDI IN/OUT connector, music keyboard connector and stereo audio out
Emulation ROMs dumped and emulated. The rear expansion slot and side module slot are handled like regular MSX cartridge slots.


The CX5F is identical to the Yamaha YIS-503, but was sold with the SFG-01 FM synthesizer module plugged into the side slot, providing MIDI IN and OUT. There is also an updated version called the SFG-05, sold separately and included with the CX5MII. From BASIC, the music firmware can be launched with CALL MUSIC or _MUSIC.



Yamaha CX5F
Yamaha CX5F box
Yamaha CX5F with manuals
Yamaha CX5F left side
Yamaha CX5F underside
Yamaha CX5F right side
Yamaha CX5F
Yamaha CX5F with box
Yamaha CX5F label
Yamaha CX5F back


SFG-01 Screen

More info about the SFG modules on these pages:


The CX5F 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 CX5F 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 CX5F, 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.

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)