IBM 3340

The IBM 3340 disk drive was also called "Winchester". The origin is not well known. One say it comes from the so-called 30-30 rifle from the firm Winchester because the drive capacity was given as two times 30MB (that is not really correct). Others say the drive was produced at the IBM location in Winchester. Whatsoever, since then all sealed disk drives, i.e. drives whose mechanical parts are protected from environmental influences, are called Winchester drives - so principally all today's hard disks, too.

The medium is a removable disk module that has the mechanics with the read/write head built-in, in contrast to the former removable disk packs. This allowed a remarkable increase in capacity because tolerances of head adjustments didn't have any influences between different drives and disk packs any more. The unusual design of a module somehow reminds one to the starship Enterprise...

Module with a capacity of 70MB

The capacity of a module is either 35MB or 70MB. Optionally, one could buy a 70MB module that contains 5 cylinders with fixed heads (one head per cylinder), so that there is one area with low access time; the time for head positioning is cancelled.

Module mounted on the drive

View of the head mechanics within the module