With the exception of MOS 3.50 where the space was reclaimed for more code, the area normally hidden by the input/output memory locations (the 768 bytes from 0xFC00-0xFEFF inclusive) in the MOS ROM contained a list of names of contributors to the system. This could be recovered by extracting the ROM and reading its contents in an EPROM programmer. Those who did not have such a device could access the ROM on a Master by setting a test bit of an access control register, then using a machine-code program to copy the ROM directly to text-mode screen memory.