Digital Equipment RW504-ZA, Service Manual

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DEC magneto optical disks meet the following standards:
594 Mbyte rewritable optical disks are Continuous Composite (CC)
format, conform to ISO/IEC 10089A; ANSI X3.212-199x and 1.2 Gbyte
optical disks meet ECMA 184 standard for CC format.
594 Mbyte write-once disks are Continuous Composite Write-Once (CCW)
format, conform to ISO/IEC DIS 11560; ANSI X3.220-199x and 1.2 Gbyte
optical disks meet ECMA 184 standard for CCW format.
• Data security through the ability to ‘‘lock’’ the library, preventing disk
removal.
• SCSI Interface
Single-ended
SCSI-2 command set
• Autochanger reliability of:
40,000 hours MTBF (Mean Time Between Failure)
300,000 MSBF (Mean Swaps Between Failure)
• Modular replacement of all major assemblies
• Digital signal processor (DSP) based servo built into the drive mechanism for
faster seek times and lower error rates
• Split optics resulting in the use of a lighter optical head for faster and more
accurate data access
• Full read and write data caching to optimize system performance
1.3 Optical Library Components
Usually each SCSI-connect peripheral requires one SCSI address. With the disk
library, however, there are two unique SCSI interface addresses— one SCSI
address for the autochanger controller and one for the drive contained in the disk
library.
The autochanger controller and the host operating system manage communication
through the SCSI bus to each drive’s unique SCSI address.
Table 1–1 is a discussion of the optical library components. Refer to Figure 1–1
for component locations.
1–2 Introduction