Microdrive Technology

If you prefer magnetic storage for digital camera or other electronic device data storage, consider the Hitachi Microdrive, originally developed by IBM and now manufactured and sold by Hitachi Global Storage Technologies. The Hitachi Microdrive has also been sold by various other companies under OEM agreements. The Microdrive is a true hard disk that spins at 3,600RPM and features a 128KB cache buffer.

Since its introduction by IBM, the Microdrive in its Compact Flash Type II-compatible form factor has increased in capacity from 170MB up to 6GB. Table 10.9 compares the specifications for current Microdrive models that use Compact Flash (CF) Type II interfaces. These drives are available in travel kits and can be used with many digital cameras and other devices that are compatible with Compact Flash Type II cards.

Table 10.9. Hitachi Microdrives in Compact Flash Type II Interface

Specifications	3K4-2	3K6-3	3K6-4	3K6-4	3K6-6
Model number	HMS360402D5CF00	HMS360603D5CF00	HMS360404D5CF00	HMS360604D5CF00	HMS360606D5CF00
Capacity	2GB	3GB	4GB	4GB	6GB
Seek time (ms)	12ms	12ms	12ms	12ms	12ms
Media transfer rate	97.9Mbps	125Mbps	97.9Mbps	125Mbps	125Mbps
Interface transfer rate (maximum)	33MBps	33MBps	33MBps	33MBps	33MBps
Sustained data transfer rate	4.3MBps7.2MBps	4.9MBps9.4MBps	4.3MBps7.2MBps	4.9MBps9.4MBps	4.9MBps9.4MBps
Operating shock	200G (2ms)	200G (2ms)	200G (2ms)	200G (2ms)	200G (2ms)
Nonoperating shock	2,000G (1ms)	2,000G (1ms)	2,000G (1ms)	2,000G (1ms)	2,000G (1ms)

All Microdrives using the CF Type II interface, including the current 3K4 and 3K6 models shown in Table 10.9, weigh 16g with dimensions of 42.8x36.4x5mm.

Tip

Hitachi uses a standard formula for its Microdrive model numbers. Use this information to quickly identify the features of a particular Microdrive model.

For example, a Microdrive with a model number of HMS361008M5CE00 has the following features:

H = Hitachi	M = Generation code (D = earlier generation)
M = Microdrive	5 = 5mm z - height
S = Standard	CE = ZIF connector PATA interface (CA = CE-ATA)
36 = 3600RPM	CM = ATA on MMC (CF = Compact Flash Type II)
10= Reserved (also 04, 06)	0 = Reserved
08 = Capacity 8GB (06 = 6GB, 04 = 4GB, 03 = 3GB)	0 = Reserved

The new 3K8 Microdrive series for embedded applications has capacities of 6GB and 8GB. The 3K8 series uses a ZIF connector to interface to PATA, CE-ATA, or ATA on MMC interfaces in devices such as mobile phones and ultra-small consumer electronics devices. Despite its higher capacity, the 3K8 actually has a smaller form factor than the 3K6 and previous Microdrive generations: It weighs just 13g, with dimensions of 40x30x5mm. The 3K8 series also features increased shock resistanceit can handle an operational shock of up to 400G (2ms).

Areal density has increased with each Microdrive generation, from as little as 5.04Gb/square inch with the original 170MB model up to 119Gb/square inch in the 3K8 series. In 4GB and larger drives, Hitachi uses a five-layer version of the Pixie Dust AFC media technology originally developed by IBM. To enable the increased areal density to be used as completely as possible, Hitachi also developed smaller hard disk read/write head technology.

Starting in 2003, Hitachi began to use femto sliders for the read/write heads used in several small hard disk series, including the Microdrive 3K6 and 3K8 as well as the Travelstar 7K60, E7K60, 7K100, E7K100, and C4K60 Slim drives. Femto sliders are only 20% of the size of the pioneering Mini hard disk slider introduced in 1980.

See the www.hitachigst.com website for more information about Microdrive products, a compatibility matrix, and other information.