Meaning you can add a 27C64 or 27C128 eprom to the adapter, and plug the adapter into one of the rom sockets of i.e. the C64, C128 etc.
To use a 27C64, you only need a 28pin socket and 2 x 12pin sil headers, preferably turned / tulip.
To use a 27C128, you need a 4k7 - 10k ohm resistor, a wire with a 2 way switch connected to the 2 pin header. This will make you able to switch between 2 rom files (each 8kB) in the 16kB eprom.
