Compaq AlphaPC 264DP Technical Reference Manual page 64

DC Power Distribution
4.8.1 Super I/O Controller
The AlphaPC 264DP uses the SMC FDC37C669 as the combination controller chip
(see Table 2–1 and Figure 2–1). It is packaged in a 100-pin PQFP configuration. The
chip provides the following ISA peripheral functions:
•
Diskette controller – Software compatible with the Intel PC8477 (contains a
superset of the Intel DP8473 and NEC PD765 and the Intel N82077 FDC func-
tions). The onchip analog data separator requires no external filter components
and supports the 4Mb drive format and 5.25-inch and 3.5-inch diskette drives.
FDC data and control lines are brought out to a standard 34-pin connector. A
ribbon cable interfaces the connector to one or two diskette drives.
•
Serial ports – Two UARTs with modem control, compatible with NS16450 or
PC16550, are brought out to separate onboard, 10-pin connectors. The lines can
be brought out through 9-pin female D-sub connectors on the bulkhead of a stan-
dard PC enclosure.
•
Parallel port – The bidirectional parallel port is brought out to an onboard 25-pin
connector. It can be brought out through a 25-pin female D-sub connector on the
bulkhead of a standard PC enclosure.
Refer to the SMC FDC37C669 specification for further information (including tim-
ing, electrical characteristics, and mechanical data).
4.8.2 ISA Expansion Slot
One ISA expansion slot is provided for plug-in ISA peripherals. This slot is shared
with the PCI and can be used for a PCI or ISA device.
4.9 DC Power Distribution
The AlphaPC 264DP derives its system power from a user-supplied power supply.
The power supply must provide +12 V dc, −12 V dc, −5 V dc, +5 V dc, 5VSB dc and
3.3 V dc. The dc power is supplied through two power connectors on the mainboard
(J3 and J33) and one on the daughtercard (J4). Power is distributed to the board logic
through dedicated power planes within the 12-layer board structure. Power is dis-
tributed to the daughtercard through the connector and dedicated 18-pin power con-
nector from the power supply.
Functional Description
4–14
12 February 1999 – Subject To Change