Historic Hard Disk Drives - Fujitsu, NEC and Seagate

This ‘Godzilla’ of a drive is a 1986 example of a enterprise grade mainframe hard disk from Fujitsu. While the translucent cover may seem unusual this is not the only differentiating factor from a classic hard disk.

This particular ‘drive’ incorporated multiple heads, side by side on the end of the arms which support these read write heads in a ‘H’ pattern.

A typical Hard Disk Drive has only a single set of heads at the tip of the arms and these arms resemble an ‘A’ pattern as per our photos.

This 1988 NEC hard disk uses a stepper motor as an actuator device to position the heads.

Stepper motors are large, bulky, noise and consume a lot of power and this technology has been replaced by voice coil motors/actuators such as is what is found in an audio speaker.

A Full-height Seagate SCSI hard disk in a is now an old external SCSI enclosure.

While computer users are familiar with form factor terminology such as 3.5” or 5.25”, what has disappeared due to progress and modernisation is the designation of height.

The form factors of drives we have known since the mid 1990s till present is what is known as half-height. Older devices could still comply to 3.5” or 5.25” width but would require double-height slot or bay to accommodate the drive.

This Seagate ST4702N is a 5.25” Full Height SCSI 600 Megabyte Hard Disk Drive form which is an example of the largest form factor available to traditional desktop PC, except here we have it inside an external SCSI enclosure. This drive was also an early example (1990) of voice coil motor technology instead of stepping motors.

The difference in size is most evident when comparing the entire unit to the adjacent 45GB IBM 3.5” Hard Disk Drive and the 5.25 HDD lid itself to the adjacent IBM Travelstar.