Mac Classic II PDS slot

[gsteemso]

Does anyone know what the 50-pin slot marked “ROM/FPU” at one edge of my Mac Classic II’s motherboard can be used for?

 

[Brendan]

Yes, that.

You answered your own question - the slot is as described:

http://en.wikipedia.org/wiki/Macintosh_Classic_II

Google is your friend.

 

[ScubaSteve]

Voila!

http://en.wikipedia.org/wiki/Macintosh_Classic_II

The Classic II has a 50-pin internal expansion slot intended for either an FPU co-processor or additional ROM. The socket is not designed to be used for any other purpose and is not suitable for use as a general expansion slot. Apple never produced an expansion card of any kind for this slot, although at least one third-party FPU was available: the FastMath Classic II by Applied Engineering.