Mega Drive Expansion

From HwB

Available at Sega Mega Drive/Genesis. Used for connection of Sega Mega-CD.

Pinout

Edge connector

Pin Name
A01 GND
A02 NC
A03 /C_OE
A04 D00
A05 D01
A06 D02
A07 D03
A08 D04
A09 D05
A10 D06
A11 D07
A12 GND
A13 D08
A14 D09
A15 D10
A16 D11
A17 D12
A18 D13
A19 D14
A20 D15
A21 Connected to pin 87 of chip 315-5364
A22 /LO_MEM
A23 Connected to pin 91 of chip 315-5364
A24 Connected to pin 86 of chip 315-5364
A25 Connected to pin 10 of chip 315-5309
A26 +5v
A27 NC
A28 VCC IN*
A29 Audio*
A30 GND
Pin Name
B01 GND
B02 Connected to pin 11 of chip 315-5309
B03 A01
B04 A02
B05 A03
B06 A04
B07 A05
B08 A06
B09 A07
B10 A08
B11 A09
B12 GND
B13 A10
B14 A11
B15 A12
B16 A13
B17 A14
B18 A15
B19 A16
B20 A17
B21 /LDS
B22 /UDSW
B23 Cart B21*
B24 Connected to pin 85 of chip 315-5364
B25 Connected to pin 10 of chip 315-5309
B26 +5v
B27 NC
B28 VCC IN*
B29 Audio*
B30 GND

Notes:

  • VCC IN - It appears the SGCD is capable of powering the main console through these pins. Power from them is routed directly to the console power switch through a pair of diodes.
  • Cart B21 - This pin connects to the cartridge slot B21, function unknown.
  • Audio - This is assumed functional, but is untested.

Sources