NOT TESTED!

This is a TSOP adapter that is meant to install on the backside of a 36-pin SNES mask ROM. You do not have to remove the mask ROM, just clip the /OE pin and tie it high.

For a 32Mb game, use two 29F160 flash chips along with a 74'00 TSOP, leave J1 open.

For a 24Mb game, you should be able to use a 29F160 for U1 and a 29F800 for U2. It still needs the 74'00 and J1 open.

For a 16Mb game or smaller, use a single TSOP (29F160, 29F800, 29F400) chip in the U1 position, do not install the 74'00, close J1.

C1, C2 and C3 are 0.01μF 0603 capacitors.

I think 0.8mm board thickness would be the better choice.

Possible problems…

J1 may give you errors if you upload this to another board house. It meets OSH Park’s DRC, but has overlap issues that you can ignore. This footprint is meant to be closed with a solder blob, but it has not yet been tested. If it gives you any issues, use a small bit of wire to close it.

Because there is one TSOP on each side of this adapter board, it cannot sit flush on the bottom of a mask ROM like you normally would want it to. Since this is not tested, it is unknown if the legs of the mask ROM are long enough to be able to solder it. I think they might be just long enough for this to not be an issue. But if it’s a problem, I plan on using 22 AWG solid core wire to bridge the gap.

Please use responsibly.