On the Emulation of TU58s

[Brent Hilpert]

On 2015-Jun-16, at 12:31 PM, Paul Koning wrote:
>> On Jun 16, 2015, at 3:20 PM, tony duell <ard at p850ug1.demon.co.uk> wrote:
>> ...
>>> The actual tape movement as such, is all done by the small wheel next to
>>> the head, which just runs the tape past the head.
>> 
>> Which is essentailly the same as the capstan in an audio tape recorder, albeit the computer
>> drive doesn't have a pinch roller
> 
> Most don’t.  Some do.  I remember using IBM tape drives on a 360 Model 44 that were amazingly badly designed.

Once ran across a Honeywell drive (7-track) that had a 'vacuum capstan'. The capstan wheel had a vacuum path through the axle and then transferred the vacuum out to holes around the perimeter. So rather than a pinch roller or rubber frictional surface on the capstan to grip the tape, it was a vacuum holding the tape to the smooth metal surface of the rotating capstan.  Or was this common on higher-end vac-column drives?