Seagate ST373405LW/LWV/LC/LCV, ST336605LW/LC/LCV manual General description

Cheetah 73LP Product Manual, Rev. E 5

3.0General description

Cheetah 73LP drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood (PRML) read channel electronics, embedded servo technology, and a wide Ultra160 SCSI interface to provide high performance, high capacity data storage for a variety of systems including engineering workstations, net- work servers, mainframes, and supercomputers.

The Ultra160 interface uses negotiated transfer rates. These transfer rates will occur only if your host adapter supports these data transfer rates and is compatible with the required hardware requirements of the I/O cir- cuit type. This drive also operates at SCSI-1 and SCSI-2 data transfer rates for backward compatibility with non-Ultra/Ultra2/Ultra3 SCSI host adapters.

Table 1 lists the features that differentiate the Cheetah 73LP models.

Table 1:	Drive model number vs. differentiating features
		Number
		of active		Number of I/O	Number of I/O
Model number		heads	I/O circuit type [1]	connector pins	data bus bits
ST373405LW/LWV		8	Single-ended (SE) and low voltage	68	16
			differential (LVD)
ST373405LC/LCV		8	Single-ended (SE) and low voltage	80	16
			differential (LVD)
ST336605LW		4	Single-ended (SE) and low voltage	68	16
			differential (LVD)
ST336605LC/LCV		4	Single-ended (SE) and low voltage	80	16
			differential (LVD)

[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.

The drive supports the Small Computer System Interface (SCSI) as described in the ANSI SCSI-2/SCSI-3 interface specifications to the extent described in this manual (volume 1), which defines the product perfor- mance characteristics of the Cheetah 73LP family of drives, and the SCSI Interface Product Manual, part num- ber 75789509, which describes the general interface characteristics of this and other families of Seagate SCSI 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 73LP 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.

An automatic shipping lock prevents potential damage to the heads and discs that results from movement dur- ing shipping and handling. The shipping lock automatically disengages when power is applied to the drive and the head load process begins.

Cheetah 73LP drives decode track 0 location data from the servo data embedded on each surface to eliminate mechanical transducer adjustments and related reliability concerns.