National Semiconductor PC87391
the PC8739x family features an X-Bus Extension for read and write operations over the X-Bus, a full IEEE 1284 Parallel Port with a Parallel Port Multiplexer (PPM) for external Floppy Disk Drive (FDD) support, a Musical Instrument Digital Interface (MIDI) port, and a Game port. The PC8739x family also incorporates: a Floppy Disk Controller (FDC), two enhanced Serial Ports (UARTs), one with Fast Infrared (FIR, IrDA 1.1 compliant), General-Purpose Input/Output (GPIO) support for a total of 32 ports, Interrupt Serializer for Parallel IRQs and an enhanced WATCHDOG™ timer. The following features apply to the PC87393F.