Read the thread viewtopic.php?f=7&t=106&p=1040&hilit=6264#p1040 and saw that it used 2x6264 to increase internal RAM to 16K. I now happend to have two 6264 laying and thought I would installed them.
I was then looking for a schematic of how to solve the RAM CS signal but could ony find schematics to 32K or 64K on Internet.
Is there anyone with a schematic over this solution with two 6264 RAM?