IBM 3380 Disk Drive


This disk drive used a servo surface and voice coils to move the read/write heads,
and used error correcting code recording technology. This involved the data recorded being
translated by an algorithm that enabled the read circuitry to detect and correct errors.
The storage capacity was 2.5GBytes

Mus.Cat. NEWUC:2007.8 Mnfctr: IBM Date: 1982 Labelled *H10125* Inscribed 8130
Comp: Disk Pack LENGTH: 655 mm WIDTH: 280 mm HEIGHT: 416 mm Weight: 29.4 Kg

This is two disk drives using one stack of disks, it has two head assemblies, one on each side.
In the front of the disk drive is a pulley around which was a belt driven by an electric motor below.

As you can see the voice coils and head assemlies are offset, each doing just half the disk surfaces.
Note that the heads move linear radially. We do not have the magnets or the motor.
This part of the disk drive alone weighed 29Kg.

This is a closeup of a voice coil, so called because it was connected to a paper diaphram in a loudspeaker,
to convert electrical signals into sound that we can hear. Here it is used to move the disc heads.

Each arm had four heads, two per surface, each with its own reflection in the disk surface.
If you left click on the image you will download the fullsize photograph, and then left click on that
to enlarge the image, and scroll down to see the other two heads behind the arms you can see.
(At least on my Firefox web browser.)