System 80 RAM Expansion

[someone]

It sits in the upper 32K. From 8000 to FFFF.
(it's a very neat layout)

Chesh

Ta,
The GAL (PALASM) equations would be very simple,  something like:
RAMCS := A15 * MREQ
RAMOE := RD
RAMWR := WR 

Note: The pins are assigned as /RAMCS, /RAMOE, /RAMWR, /MREQ, /RD, /WR & A15 to get the correct logic sense.

So simple that you might get away just using a 74xx00.