Apple IIgs System Timing and the FPI

The Apple IIgs has a split personality. Most of the machine runs at a ~1MHz clock rate, keeping compatibility with earlier Apple IIs. Some components, however, can be decoupled and run at a faster rate. The FPI, or Fast Processor Interface, is the chip responsible for coordinating the interactions between these personalities. This session by Daniel Kruszyna will include a high level overview of the FPI’s responsibilities, along with a detailed look at some particular cases, using signal measurements obtained from a real Apple IIgs.