Seagate ST336918N, ST318418N manual General description, Barracuda 36ES2 Product Manual, Rev. B

Barracuda 36ES2 Product Manual, Rev. B 5

3.0General description

Barracuda 36ES2 drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood (PRML) read channel electronics, embedded servo technology, and a wide SCSI Ultra160 interface to provide high performance, high capacity data storage for a variety of systems including engineering workstations, net- work servers, mainframes, and supercomputers.

Ultra160 SCSI 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 circuit type. This drive also operates at Ultra160 data transfer rates.

Table 1 lists the features that differentiate the Barracuda 36ES2 models.

Table 1:	Drive model number vs. differentiating features
		Number
		of active		Number of I/O	Number of I/O	Data buffer
Model number		heads	I/O circuit type [1]	connector pins	data bus bits	size
ST336938LW		2	Single-ended (SE) and low	68	16	2 Mbytes
			voltage differential (LVD)
ST336918N		2	Single-ended (SE)	50	8	2 Mbytes
ST318438LW		2	Single-ended (SE) and low	68	16	2 Mbytes
			voltage differential (LVD)
ST318418N		2	Single-ended (SE)	50	8	2 Mbytes

[1]See Section 9.6 for details and definitions.

The drive records and recovers data on approximately 3.74-inch (95 mm) non-removable discs.

The drive supports the Small Computer System Interface (SCSI) as described in the ANSI SCSI interface specifications to the extent described in this manual (Volume 1), which defines the product performance char- acteristics of the Barracuda 36ES2 family of drives, and the SCSI Interface Product Manual, part number 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, 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.

Never disassemble the HDA and do not attempt to service items in the sealed enclosure (heads, media, actu- ator, etc.) as this requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.

Barracuda 36ES2 drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility 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.

Barracuda 36ES2 drives decode track 0 location data from the servo data embedded on each surface to elimi- nate mechanical transducer adjustments and related reliability concerns.

Ahigh-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides excellent performance with minimal power dissipation.