Memory attached to a software carrier of a computer game machine

An auxiliary memory device connected between a computer game machine and a software carrier having a built-in writable memory. The auxiliary memory device includes a large-capacity writable memory, a user input means for inputting a section number to select a corresponding section of the auxiliary memory. A logical control circuit of the auxiliary memory device substitutes a selected section of the auxiliary memory for a writable memory of the software carrier as the storage location for state of play data at the end of an unfinished game. Different users can use the software carrier of the same computer game machine by selecting different storage sections in the auxiliary memory to record their state of play data. The result is equivalent to each user having his own software carrier, thereby overcoming the contradiction that arises when several users share the same software carrier.