Avago Technologies LSI53C120 - Manual (Page 24)

16 LSI20101/LSI20102 SCSI Bus Boards
4.4.3 Subsystem Interface Connector J4
A-Side and B-Side SE termination circuitry provides termination for the
SCSI buses. Onboard termination for each of the two physical buses is
controlled in one of two ways: by switches or by the subsystem interface
(J4).
Switches – The LSI20102 board contains the following four switches at
location U8. See
Table 9 .
Termination Interface – The termination control on the LSI20102
board permits the connection of a subsystem harness for external control
of the onboard SCSI terminators.
Table 9 U8 Switches
Switch Position Condition Description
SW1
ON Supplied by LSI20102 SE
OFF Not supplied by LSI20102 TERMPWR
SW2
ON Supplied by LSI20102 DIFF
OFF Not supplied by LSI20102 TERMPWR
SW3
ON Disabled SE
OFF Enabled Termination
SW4
ON Disabled DIFF
OFF Enabled Termination