Slim Hard Disk Units (Optional) - AT&T 6300 Service Manual

SYSTEM OVERVIEW
Slim Hard Disk Units (Optional)
lO-MB Hard Disk Unit
One of the MFD Units may be replaced with a 10-MB (formatted)
Hard Disk Unit (HDU). The HDU (Figure 2-14) is a random
access 5.25-inch slim (half-height) Winchester storage device with
two nonremovable disks as storage n1edia. Each disk surface has
one movable head to service 306 data tracks. This Slim HDU is
the same physical size and mounts the same as the MFD Unit. It
also uses the same dc voltages as the MFD Unit. The installation
of this HDU requires a minimum of 256-KB RAM.
20-MB Hard Disk Unit
One of the MFD Units may be replaced with a 20-MB (formatted)
Hard Disk Unit (HDU). The HDU (Figure 2-14) is a random
access 5.25-inch slim (half-height) storage device with two
nonremovable disks as storage media. Each disk surface has one
movable head to service 612 data tracks. This Slim HDU is the
same physical size and mounts the same as the MFD Unit. It also
uses the same dc voltages as the MFD Unit. The installation of
this HDU requires a minimum of 256-KB RAM.
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