A quick attempt at dumping the BIOS EPROM from the Pioneer LaserActive PAC-S1.

The dump itself exposed some odd behaviour from my GQ-4X programmer, so the programmer needed more investigation before I could fully trust the result.

The chip has a sticker over the erase window marked PIONEER PD6126E. Underneath is a Fujitsu MBM27C1024A-12Z, dated to week 28 of 1993.

The MBM27C1024A is a 1 Mbit UV-erasable EPROM in a 40-pin package.

Sources