Archive PYTHON 4322 Product Description Manual page 39

ARCHIVE PYTHON DDS-DC DA T DRIVES---PRODUCT DESCRIPTION MANUAL
SCSI Mode at Power-Up (S4)
The S4 switch selects either SCSI-lor SCSI-2 as the default operational mode for the Python SCSI bus at
power-up. The default is SCSI-2 (S4
=
ON), a superset of SCSI-I. Chapter 5 provides more information
about the SCSI-l and SCSI-2 interfaces.
S4
=
ON selects SCSI-2
S4
=
OFF selects SCSI-l
Parity Check Enable/Disable (S5)
The S5 switch enables or disables parity checking for the SCSI bus. The default is parity disabled (S5 =
OFF).
S5
=
ON enables parity checking
S5
=
OFF disables parity checking
DDS Pass-Through Mode Enable/Disable (S6)
The S6 switch enables or disables DDS pass-through mode. The default is DDS pass-through mode disabled
(S6=OFF).
S6
=
ON enables DDS pass-through mode
S6 = OFF disables DDS pass-through mode
NOTES: When
S6
is OFF, DDS-DC data compression
is
enabled during writing. When
S6
is
ON, DDS-DC data compression is disabled. When reading, DDS-DC compressed
data is always decompressed, regardless of the position of S6.
The function of the
S6
switch can be over-ridden by the proper SCSI MODE SELECT
command issued from the host computer. Regardless of the position of S6, the MODE
SELECT command can enable or disable data compression.
Reserved Switch (S7)
The S7 switch is reserved and should be left in its factory default setting.
Power-on Self-Test Mode Enable/Disable (Sa)
The S8 switch enables or disables execution of power-on self-test diagnostics when the power comes ON.
The default is power-on self-test mode disabled (S8 = OFF). If ON, the drive responds to SCSI commands
after successful completion of the test (about 5 seconds). .
S8
=
ON enables power-on self-test mode
S8
=
OFF disables power-on self-test mode
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