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Genesis/Megadrive cartridge pinout

The following table describes the pinout for the Genesis/Megadrive cartridge port. With the console facing you, row A is the rearmost row, and row B is the frontmost row. Numbering starts from left to right.

A01GNDGround-B01SL1Sound input left
A025vVCC1-B02!HRSTHard reset
A03A08Address 08-B03SR1Sound input right
A04A11Address 11-B04A09Address 09
A05A07Address 07-B05A10Address 10
A06A12Address 12-B06A18Address 18
A07A06Address 06-B07A19Address 19
A08A13Address 13-B08A20Address 20
A09A05Address 05-B09A21Address 21
A10A14Address 14-B10A22Address 22
A11A04Address 04-B11A23Address 23
A12A15Address 15-B12!YSVideo
A13A03Address 03-B13!VSyncVsync
A14A16Address 16-B14!HSyncHSync
A15A02Address 02-B15HS_CLKVCLK
A16A17Address 17-B16!C_OE!AS
A17A01Address 01-B17!C_CE!CE0
A18GNDGround-B18!ASAddress strobe
A19D07Data 7-B19CLK68000 clock
A20D00Data 0-B20!DTACKData ack
A21D08Data 8-B21!CAS_2!CAS_2
A22D06Data 6-B22D15Data 15
A23D01Data 1-B23D14Data 14
A24D09Data 9-B24D13Data 13
A25D05Data 5-B25D12Data 12
A26D02Data 2-B26!LO_MEM!ASEL
A27D10Data 10-B27!RST 68K reset
A28D04Data 4-B28!LDSLower data strobe
A29D03Data 3-B29!UDSWUpper data strobe
A30D11Data 11-B30!SRSTSoft reset
A32GNDGround-B32!C_DTCTCart detect - disables onboard ROM(s)

Address and Data busses are from the 68000 perspective.
VCC1 supplies power to the 68000 and the YM2612 and possibly some other minor parts.
VCC2 supplies power to the Z80, memory and custom chips. They are generated by two seperate voltage regulators.
CLK and HS_CLK are not synchronous, just in case you want to do anything funky (like I did).

schematics/megadrivecart.txt · Last modified: 2019/08/27 20:45 by