Category: Peter Schepers Archive

ROM updates & working with EPROMs

The ROM’s in the C64 and the original 1541 models are 24 pin and are not directly pin compatible with burnable 2732 or 2764 EPROMS. In order to upgrade to a newer ROM revision or change the ROM to something else and use either a 2732 (for the character set) or 2764 (for kernal/DOS) EPROM, a socket adapter must be built. See here for detailed instructions on how to build one.

Making Commodore 64 ROM Socket Adapters

Socket adapters are required on the original C64 and 1541 models when replacing the existing 24-pin ROM with a 28-pin EPROM, like a 2764 or larger. They are also needed if you want to replace a 2764 with a larger 27128, a 27128 with a 27256 or a 27256 with a 27512. All of these adapters are covered here.