Genesis Carts

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Designs for several versions of Genesis cartridges I’ve designed.

TL866CS Adapter Board

Several of the Genesis cartridge PCBs I have designed are programmed directly by a TL866CS programmer after the board is assembled. These boards all use 29Fx00 16bit flash ICs or equivalents in SOP-44 packages. To permit programming the ICs after soldering I determined the pinout the TL866CS SOP-44 adapter and designed a PCB which converts the Sega Genesis edge connector to a TL866CS compatible pin sequence which allows the TL866CS to “see” the flash ICs on the PCB.

 

#TODO add TL866CS pinout

16Mbit SRAM SMT Board

The following board supports up to 16Mbit games with 32KB battery-backed SRAM or FRAM. This board is programmable through the Genesis edge connector due to the #WE signal being routed to one of the +5V pins.

Specifications

  • 2 slots of 8Mbit x29Fx00 Flash ICs
    • Allows configurations of 2Mbit up to 16Mbit
  • 32KB SRAM/FRAM footprint
    • Allows FRAM FM1808 or AS6C62256 SRAM (required battery)
  • Advanced battery circuit ensures no leakage through #CE pin without expensive battery monitor IC
  • Battery can be replaced without any soldering
  • Flash ICs programmable through Genesis edge connector
  • 74HC139 address decoder

Programming

This cartridge can be programmed through the TL866CS adapter board. You must swap the bytes in the binary file prior to programming because the M68000 is a big-endian CPU. For 16Mbit ROMs, each 8Mbit IC must be programmed individually. The ROM must be split into corresponding 8Mbit files, and the corresponding low and high ROM jumpers must be selected on the TL866CS adapter board.

Schematic

8Mbit SMT Board

The following board supports up to 8Mbit games. This board is programmable through the Genesis edge connector due to the #WE signal being routed to one of the +5V pins.

Specifications

  • 1 slot 8Mbit x29Fx00 Flash IC
    • Allows 2Mbit up to 8Mbit

Programming

This cartridge can be programmed through the TL866CS adapter board. You must swap the bytes in the binary file prior to programming because the M68000 is a big-endian CPU.

Schematic

Dimensions

Sega Genesis cartridge PCBs are 1.6mm thick.

René

Electronics engineer and retrogaming fanatic!