The PD75P108B is a version of the PD75108 in which the on-chip mask ROM is replaced by one-time PROM which can be written to once only, or EPROM which is capable of program write, erasure and rewrite. Also, since the PD75P108B is capable of program write by a user, it can easily be exchanged with the mask version, allowing evaluation at low voltage. Detailed functional descriptions are shown in the following User's Manual. Be sure to read for designations. PD751xx Series User's Manual : IEM-922