Digital Equipment RW504-ZA, Service Manual

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Table 1–1 RW504/RW524 Components
Component Description
Disk Drive The optical disk library contains one multifunction optical
disk drive for read/write data transfer. The drive requires
its own unique SCSI address and is located next to the front
panel at the bottom of the optical library. See Section 1.3.1 for
additional drive information.
Storage Slots The optical disk library contains 16 storage slots for holding
optical disks.
Mailslot The mailslot is used to insert or remove optical disks from the
disk library.
Front Panel The front panel includes a control panel used to manage and
display library functions and a mailslot for inserting and
removing disks. Control panel functions are described in
Section 3.1.
Rear Panel The rear panel includes SCSI and power cord connections,
a fuse receptacle, a 9-pin serial connector for attaching an
uninterruptable power supply (UPS), and a voltage select
switch.
Rail and Carriage The rail and carriage support the picker for its movement
within the disk library.
Picker The picker rotates, flips, and transports optical disks to and
from the storage slots, mailslot, and optical drive.
The RW504/RW524 is available as a single-ended SCSI interface.
1.3.1 The Optical Drive Mechanism
The optical drive mechanism is a multifunction drive and, therefore, operates
in both rewritable and write-once modes. The drive uses both rewritable and
write-once 5.25-inch magneto-optical disks that comply with ANSI and ISO
standards for Continuous Composite format. The drive senses the disk type and
automatically operates in either rewritable or write-once mode.
The drive has a 3600 rpm rotational speed and can achieve a maximum sustained
write transfer rate of 0.5 to 0.8 Mbytes per second and a maximum sustained
read transfer rate of 1- to 1.6-Mbyte per second, depending on the media and
drive capacity. The error rate is less than one block in error per
10 14
bytes.
Immediate response mode and write caching are used by the drive mechanism
to achieve its high write performance. However, if a power failure occurs while
write data is in the buffer, the drive may not have enough power to complete
the write operation and empty the buffer. Therefore we recommend that an
1–4 Introduction