Seagate Cheetah 18LP, Руководство по эксплуатации продукта, Страница: 15 / 94

Cheetah 18LP Product Manual, Rev. F 5
3.0 General description
Cheetah 18LP drives combine dual stripe magnetoresistive (DSMR) heads, partial response/maximum likeli-
hood (PRML) read channel electronics, embedded servo technology, and a wide Ultra2 (Ultra160 on
ST318233 and ST39133 models) SCSI interface to provide high performance, high capacity data storage for a
variety of systems including engineering workstations, network servers, mainframes, and supercomputers.
The SCSI interface uses negotiated transfer rates. These transfer rates will occur only if your host adapter sup-
ports these data transfer rates and is compatible with the required hardware requirements of the I/O circuit
type. This drive also operates at SCSI-1 and SCSI-2 data transfer rates for backward compatibility with non-
Ultra/Ultra2/Ultra160 SCSI host adapters.
Table 1 lists the features that differentiate the two Cheetah 18LP models.
Table 1: Drive model number vs. differentiating features
[1] See Section 9.6 for details and definitions.
The drive records and recovers data on approximately 3.3-inch (84 mm) non-removable discs.
ST318203 and ST39103 model drives support the Small Computer System Interface (SCSI) as described in
the ANSI SCSI interface specifications to the extent described in this manual, which defines the product perfor-
mance characteristics of these drives, and the SCSI Interface Product Manual, part number 77738479, which
describes the general interface characteristics of these drives.
ST318233 and ST39133 model drives support the Small Computer System Interface (SCSI) as described in
the ANSI SCSI interface specifications to the extent described in this manual, which defines the product perfor-
mance characteristics of these drives, and the SCSI Interface Product Manual, part number 75789509, which
describes the general interface characteristics of these drives.
The drive’s interface supports multiple initiators, disconnect/reconnect, self-configuring host software, and
automatic features that relieve the host from the necessity of knowing the physical characteristics of the targets
(logical block addressing is used).
The head and disc assembly (HDA) is sealed at the factory. Air circulates within the HDA through a non-
replaceable filter to maintain a contamination-free HDA environment.
Refer to Figure 2 for an exploded view of the drive. This exploded view is for information only—never disassem-
ble the HDA and do not attempt to service items in the sealed enclosure (heads, media, actuator, etc.) as this
requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.
Cheetah 18LP drives use a dedicated landing zone at the innermost radius of the media to eliminate the possi-
bility of destroying or degrading data by landing in the data zone. The drive automatically goes to the landing
zone when power is removed.
Model number
Number
of active
heads
I/O circuit type [1]
Number of I/O
connector pins Number of I/O
data bus bits
SCSI interface
ST318203LW/LWV
ST39103LW/LWV 12
6 Single-ended (SE)
and low voltage
differential (LVD) 68 16 Ultra2
ST318203LC/LCV
ST39103LC/LCV 12
6 Single-ended (SE)
and low voltage
differential (LVD) 80 16 Ultra2
ST318233LWV
ST39133LWV 12
6 Single-ended (SE)
and low voltage
differential (LVD) 68 16 Ultra160
ST318233LCV
ST39133LCV 12
6 Single-ended (SE)
and low voltage
differential (LVD) 80 16 Ultra160