I/O Subsystem - Texas Instruments Extensa 51x Maintenance Manual

4.2.2

I/O Subsystem

The I/O subsystem, implemented with an NS87334 VJG Super I/O
Controller Chip, provides for such functions as internal Hard Drive control,
floppy drive control, and serial and parallel ports. The Super I/O Controller
includes the following features:
100 percent compatible with ISA, EISA, and Micro-channel architectures
Built-in Floppy Disk Controller
Software compatible with the DP8473, the 765A and N82077
16-byte FIFO (default disabled)
Burst and Non-burst modes
Perpendicular Recording drive support
New high-performance internal digital data separator (no external
filter components required)
Low-power CMOS with enhanced power-down mode
Automatic media-sense support
Two UARTs
Software compatible with the PC16550A and PC16450
MIDI compatible
Infrared support on UART2 (IRDA -compliant)
Bidirectional Parallel Port
Enhanced Parallel Port (EPP) compatible
Extended Capabilities Port (ECP) compatible, including level 2
support
Bidirectional under either software or hardware control
Compatible with ISA, EISA, and Micro Channel architectures
Ability to multiplex FDC signals on parallel port pins for external
FDD
Includes protection circuit against damage caused when printer is
powered up, or operated at higher voltages
Integral IDE controller
Provides a complete IDE interface with DMA control (except for
optional buffers)
Theory of Operation 4-3