Both the NES and Famicom have expansion ports that allow peripheral devices to be connected to the system.
See also: Input devices
The Famicom has a 15-pin (male) port on the front edge of the console.
Because its two default controllers were not removable like the NES, peripheral devices had to be attached through this expansion port, rather than through a controller port as on the NES.
This was commonly used for third party controllers, usually as a substitute for the built-in controllers, but sometimes also as a 3rd and 4th player.
(top) Famicom (bottom)
Male DA-15
/\
| \
joypad 2 /D0 ?? | 08 \
| 15 | -- +5V
joypad 2 /D1 -> | 07 |
| 14 | -> /OE for joypad 1 ($4016 read strobe)
joypad 2 /D2 -> | 06 |
| 13 | <- joypad 1 /D1
joypad 2 /D3 -> | 05 |
| 12 | -> OUT0 ($4016 write data, bit 0, strobe on pads)
joypad 2 /D4 -> | 04 |
| 11 | -> OUT1 ($4016 write data, bit 1)
/IRQ ?? | 03 |
| 10 | -> OUT2 ($4016 write data, bit 2)
SOUND <- | 02 |
| 09 | -> /OE for joypad 2 ($4017 read strobe)
Gnd -- | 01 /
| /
\/
The NES has a 48-pin card edge located on the underside of the NES, beneath a plastic tab which must be cut or broken to expose the connector. The connector is exceptionally thick (2.6mm), thicker than standard PCB thicknesses. The port containing the connector is slightly keyed in the front-side corners.
Because the NES had controller ports on the front that allowed different devices to be plugged in, the expansion port was a kind of "back up plan" for Nintendo that was never used commercially.
(back) NES (front)
+-------\
+5V -- |01 48| -- +5V
Gnd -- |02 47| -- Gnd
Audio mix input -> |03 46| -- NC
/NMI <> |04 45| -> OUT2 ($4016 write data, bit 2)
A15 <- |05 44| -> OUT1 ($4016 write data, bit 1)
EXP9 ?? |06 43| -> OUT0 ($4016 write data, bit 0, strobe on sticks)
EXP8 ?? |07 42| ?? EXP0
EXP7 ?? |08 41| ?? EXP1
EXP6 ?? |09 40| ?? EXP2
EXP5 ?? |10 39| ?? EXP3
($4017 read strobe) /OE for joypad 2 <- |11 38| ?? EXP4
joypad 1 /D1 -> |12 37| -> /OE for joypad 1 ($4016 read strobe)
joypad 1 /D3 xx |13 36| xx joypad 1 /D4
/IRQ <> |14 35| xx joypad 1 /D0
joypad 2 /D2 -> |15 34| -> duplicate of pin 37
joypad 2 /D3 xx |16 33| <- joypad 1 /D2
duplicate of pin 11 <- |17 32| <> CPU D0
joypad 2 /D4 xx |18 31| <> CPU D1
joypad 2 /D0 xx |19 30| <> CPU D2
joypad 2 /D1 -> |20 29| <> CPU D3
Video out <- |21 28| <> CPU D4
Amplified audio <- |22 27| <> CPU D5
unregulated power adapter vdd -- |23 26| <> CPU D6
4.00MHz CIC CLK <- |24 25| <> CPU D7
+-------/
Categories: Pinouts