an Sega Megadrive/Genesis , 4Mo FRAM save repro PCB 

who support 4mo max rom size with 32kb of FRAM

all parts are DIP , easy to assemble yourself

need use an 27c400/800/160/322 eprom , and solder JP1 in position who depend of eprom type ( 27c322 pinout a little different )

need a DIP fram , an FM-1608-120PG ( 8kb ) or an FM1808-70-PG ( 32kb )

one 47uf capacitor , four 100nf capacitor ( can be less depend what game and parts populated on pcb ) , one 10k resistor ( for the fram ) and one 0 ohms resitor

bridge JP2 only if want use it an no save game pcb ( 74ls139 is bypassed ) just eprom and 47uf+ one 100nf capacitor needed in this case

if 2mo game with save 74ls139 needed

if 4mo game with save 74ls139 and 74ls74 needed

you can use 74HC139 and 74HC74 too , but dont mix LS and HC chips

a 0 ohms resistor is used in ''1'' or 2' depend of the game save , you can use a dip switch instead of it too

need order pcb in enig and 1.6mm thickness

if you want use soic28 fram , like FM18W08-SG , FM16W08-SG , often used in gameboy project , or equivalent pinout i have designe an adaptator , search for it in my other projects

Card Egde Detail

Please check if the "Edge connector" is selected as shown in the image when placing the order.

UPDATE:

pcb revision 1.2

have add an 43th hole for the WE signal , for make the possibility to make a flashcard with an adaptator i have designed

can reflash it easily with a krikzz flashkit md programmer or other

see the latest picture

just put a DIP switch instead of the 0 ohs resistor for change the setting who depend of the running game , and set the pcb like for 27c322.