Interface Cable Length For Asynchronous Operation; Interface Cable For Fast Scsi Operation; Options Jumper Block - Seagate MEDALIST 1080SL Product Manual

Medalist 1080sl SCSI Product Manual, August 1995
To minimize noise, use 28 AWG or larger 50-conductor flat cable or
25-conductor twisted-pair ribbon cable. The following are part numbers
for nonshielded flat cables we recommend:
Part Manufacturer
Flat Cable 3M-3365-50
Twisted Pair Spectra Twist-N-Flat 455-248-50
2.5.1 Interface cable length for asynchronous
operation
The SCSI interface cable must meet the following requirements for
normal operation:
The cable cannot be longer than 6.0 meters.
Cable stubs cannot be more than 0.1 meter long and must be
separated by at least 0.3 meter.

2.5.2 Interface cable for Fast SCSI operation

When using fast synchronous data transfer rates, the SCSI interface
cable must meet the following additional requirements:
The cable cannot be longer than 3.0 meters.
The cable should not attenuate a 5 MHz signal more than 0.095 dB
per meter.
The DC resistance at 20°C must not exceed 0.230 ohms per meter.
A shielded, twisted-pair cable should not have a propagation delay
delta greater than 20 nsec per meter.

2.6 Options jumper block

The ST51080N options jumper block (see Figure 4) allows you to
manually:
Enable or disable active termination
Set the SCSI ID address
Select the terminator power source
Enable parity
Activate the motor start/stop option
Attach a remote LED
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