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AM-64x DAT High Capacity Tape Drives
PDI-00649-00, A01
Figures 1 and 2 show the location of the AM-647 on-board terminators. Refer to Figure 7 for the location
of the AM-648 on-board terminators.
AM-648 ON-BOARD TERMINATORS
Figure 7 - AM-648 (Exabyte) On-Board Terminators
External SCSI Bus Termination
The preferred way to terminate the SCSI bus in an AMOS computer is to install an external terminator.
In April of 1993, the external SCSI bus terminator became standard on all AMOS computers. Using an
external terminator makes it easier to install an add-on subsystem (like a portable CD-ROM drive),
eliminating the need to remove terminators from a SCSI device inside the computer.
As computer performance increases, the SCSI bus becomes more sensitive to termination issues. Newer
AMOS computers, such as the AM-6000, require active termination of the SCSI bus. Check your
computer Owner’s Manual to make sure you are terminating the SCSI bus properly.
External terminators are available from Alpha Micro under part numbers PRA-00222-00 (narrow passive
terminator), PRA-00222-21 (narrow active terminator), and PRA-00222-20 (wide active terminator).
To use the external terminator, you need to insure none of the SCSI devices inside the computer are
terminated. You also need to follow the guidelines in the section on providing termination power to the
SCSI bus.
