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Chapter 3
Interface Boards and Mass-Storage
Drivers
SCSI/LAN Combination Board
SCSI Interface
The Symbios Logic SYM5C875JE PCI-SCSI I/O Processor chip connects the SCSI bus
directly and generates timing and protocol in compliance with the SCSI standard. The
following hardware functional diagram shows the SCSI part of the SCSI/LAN Combo
board.
Figure 3-5. SCSI Part of the SCSI/LAN Combo Board
The SCSI interface operates as a 16-bit, synchronous or asynchronous, single-ended bus,
and supports Ultra SCSI protocols and 16-bit arbitration. The interface is made through
two (and only two) of the following connectors:
Table 3-3. SCSI Interface Connectors
Connector
Description
Location
Comments
J3
Internal Wide SCSI connector.
Non-shielded 68-pin high density
right-angle receptacle.
Internal connector at
the end of the board.
Connectors J3 and J9
cannot be connected
to any devices at the
same time. If they are,
this results in a badly
“terminated” SCSI
bus. Refer to the
previous page for
further details.
J7
External wide SCSI connector.
Shielded 68-pin high density
right-angle receptacle.
Protrudes through the
rear panel bracket.
J9
Internal narrow SCSI connector.
Non-shielded 50-pin low-density
straight receptacle.
Located between the
Symbios Logic chip
and Internal side
SCSI connector.
PCI Bus
SCSI Controller
SYM53C875JE
Flash Memory
28F010
128 KB
VPP Transla-
tor
12V
2 KB
EEPRO
M
Clock
Data
Osc.
40 MHz
LED connector
(not loaded)
SCSI
68-pin high density
68-pin high density
To ExtStart Connector
External connector (16
Ext.
Internal connector (16
5V
SCSI
Bus
Termi-
nation
Fuse 3A
Termination
50-pin
Internal connector
(8 bits)
Содержание X Class 500/550MHz
Страница 6: ...6 Contents ...
Страница 8: ...8 Figures ...
Страница 15: ...15 1 System Overview ...
Страница 66: ...66 Chapter2 System Board Devices on the ISA Bus ...
Страница 96: ...96 Chapter3 Interface Boards and Mass Storage Drivers Connectors and Sockets ...
Страница 134: ...134 Chapter5 Tests and Error Messages Beep Codes ...
Страница 135: ...135 A Regulatory Information and Warranty ...
Страница 146: ...146 AppendixA Regulatory Information and Warranty HP Hardware Warranty ...