Yamaha Module Slot Connector
This page was last modified 15:04, 16 December 2021 by Mars2000you. Based on work by Gdx and Rderooy and others.
Empty module slot at underside of Yamaha YIS-503II
Yamaha SFG-05 module



The Yamaha Module Slot is a connector found on almost all Yamaha MSX computers, and several computers that Yamaha manufactured on behalf of other vendors. It is a 60-pin connector, which is 10-pins more then a standard MSX cartridge slot. The modules have a central screw with which they are held in place on most systems.

With the Yamaha UCN-01 "Unit Converter", a Yamaha module can be connected to a regular MSX cartridge slot. However due to the difference in pins, not all modules will function correctly with the Unit Converter, in particular modules with video-out or sound-out.


Pins 1 through 10 are unique to the Yamaha Module Slot. The remaining signals map 1-1 to a standard MSX Cartridge slot.

Pin Name Type Description
2 GND PWR Signal ground
3 GND PWR Signal ground
4 Phase Control I
5 Y O
6 B-Y O
8 R-Y O
11 /CS1 O ROM addresses 4000-7FFF select signal
12 /CS2 O ROM addresses 8000-BFFF select signal
13 /CS12 O ROM addresses 4000-BFFF select signal (for 256k ROM)
14 /SLTSL O Slot select signal
15 RSV (N.C) Reserved signal line - use inhibited
16 /RFSH O Refresh cycle signal
17 /WAIT I CPU's WAIT request signal
18 /INT I Interrupt request signal to CPU
19 /M1 O Signal expressing CPU fetch cycle
20 /BUSDIR I This signal controls direction of external databus buffer
Cartridges are selected and L level is output from each
cartridge at data transmission time
21 /IORQ O I/O request signal
22 /MERQ O Memory request signal
23 /WR O Write timing signal
24 /RD O Read timing signal
25 /RESET O System reset signal
26 RSV(N.C) Reserved signal line - use inhibited
27 A9 O Address bus signals
28 A15 O Address bus signals
29 A11 O Address bus signals
30 A10 O Address bus signals
31 A7 O Address bus signals
32 A6 O Address bus signals
33 A12 O Address bus signals
34 A8 O Address bus signals
35 A14 O Address bus signals
36 A13 O Address bus signals
37 A1 O Address bus signals
38 A0 O Address bus signals
39 A3 O Address bus signals
40 A2 O Address bus signals
41 A5 O Address bus signals
42 A4 O Address bus signals
43 D1 I/O Data bus signals
44 D0 I/O Data bus signals
45 D3 I/O Data bus signals
46 D2 I/O Data bus signals
47 D5 I/O Data bus signals
48 D4 I/O Data bus signals
49 D7 I/O Data bus signals
50 D6 I/O Data bus signals
51 GND PWR Signal ground
52 CLOCK O CPU clock 3.579545MHz
53 GND PWR Signal ground
54 SW1 For insertion/removal protect
55 +5V PWR +5V power source
56 SW2 For insertion/removal protect
57 +5V PWR +5V power source
58 +12V PWR +12V power source
59 SOUNDIN I Sound input signal (-5bdm)
60 -12V PWR -12V power source

Systems with the Yamaha module slot

Model Generation Standard module
Sakhr AX-100 MSX1
Sakhr AX-200 MSX1 SFG-05 FM Sound Synthesizer Unit II on AX-200M
Sakhr AX-500 MSX2
Victor HC-5 MSX1
Victor HC-6 MSX1
Victor HC-60 MSX1 HC-A502F RF TV Module
Yamaha CX5 MSX1 SFG-01 FM Sound Synthesizer Unit
Yamaha CX5F MSX1 SFG-01 FM Sound Synthesizer Unit
Yamaha CX5M MSX1 SFG-01 FM Sound Synthesizer Unit
Yamaha CX5MII MSX1 SFG-05 FM Sound Synthesizer Unit II
Yamaha CX7/128 MSX2
Yamaha CX7M/128 MSX2 SFG-05 FM Sound Synthesizer Unit II
Yamaha CX11 MSX1 SFG-01 FM Sound Synthesizer Unit
Yamaha YIS-303 MSX1
Yamaha YIS-503 MSX1
Yamaha YIS-503F MSX1 SRE-01 unit on YIS-503FB model
Yamaha YIS-503II MSX1
Yamaha YIS-503IIR MSX1 Serial I/O Unit
Yamaha YIS-503IIIR MSX2 Serial I/O Unit Mk II
Yamaha YIS-603 MSX1
Yamaha YIS-604/128 MSX2
Yamaha YIS-805/128 MSX2 SKW-05 Kanji Word Processor Unit II
Yamaha YIS-805/128R2 MSX2 Serial I/O Unit Mk II
Yamaha YIS-805/256 MSX2 SKW-05 Kanji Word Processor Unit II

Systems without the Yamaha module slot

All the other MSX systems don't have a Yamaha module slot. However, Yamaha has released a Yamaha SX-101 slot expander that adds a second standard cartridge slot and a specific module slot to the Victor HC-30 and Yamaha SX-100 computers.

If another computer has a slot with a 56-pin compatible connector, it might be possible to transform any 'normal' MSX machine into a Yamaha MSX music computer.

Module slot cartridges

Product Description
NHK NSFG-05 re-branded SFG-05
Victor HC-A502F RF TV module (pre-installed in HC-60)
Victor HC-A602S Superimposing module (built-in in HC-7)
Yamaha SCA-01 Interface for Captain connection
Yamaha SFG-01 FM Sound Synthesizer Unit
Yamaha SFG-05 FM Sound Synthesizer Unit II
Yamaha SFK-01 FM Sound Synthesizer Unit (without MIDI)
Yamaha SKW-01 Kanji Word Processor Unit
Yamaha SKW-05 Kanji Word Processor Unit II (built-in in YIS-805/128 and YIS-805/256)
Yamaha SMD-01 MIDI Unit
Yamaha SRE-01 32kB RAM expansion + Unit Converter
Yamaha SRG-01 RGB Unit
Yamaha SRM-01 32kB RAM expansion + RGB output
Yamaha STC-01 Modem/Word Processor
Serial I/O Unit (used with YIS-503IIR)
Yamaha CB55448 Serial I/O Unit Mk II (used with YIS-503IIIR and YIS-805-128R2)