Functional Description
3–9
ISA Bus Devices
3.3.1 Combination Controller
The AlphaPC 164UX uses the Standard Microsystems Corporation FDC37C666
Super I/O combination controller chip (see Figure 3–4). It is packaged in a 100-pin
QFP configuration. The chip provides the following ISA peripheral functions:
•
Diskette controller–Software compatible to the Intel N82077 FDC. Integrates
the functions of the formatter/controller, digital data separator, write precom-
pensation, and data-rate selection logic requiring no external filter compo-
nents. Supports the 2.88MB drive format and other standard diskette drives
used with 5.25-inch and 3.5-inch media. FDC data and control lines are
brought out to a standard 34-pin connector (J33). A ribbon cable interfaces the
connector to one or two diskette drives.
•
Serial ports–Two UARTs with full modem control, compatible with NS16450
or PC16550 devices, are brought out to two separate onboard, 9-pin
D-subminiature connectors (J12).
•
Parallel port–The bidirectional parallel port is brought out to an onboard 25-pin
connector (J13). It can be brought out through a 25-pin female D-subminiature
connector on the bulkhead of a standard PC enclosure.