IBM 5155 Manual To Operations page 322

Requirements
• The 64/256KB Memory Expansion Option comes
with 64K of total memory. You may insta1164KB
Memory Module Kits on this option to increase its
memory up to 256K.
• If you have purchased memory module kits to install
on this option, you must install them before
installing the 64/256KB Memory Expansion Option
on your system board.
2 64/256KB Memory Expansion
January 1984