19 Jul
2010
19 Jul
'10
4:03 p.m.
On 7/19/10 6:37 PM, Chuck Guzis wrote:
Every vacuum-column drive I've seen has used pressure sensors to
determine the position of the tape loops within the columns. Granted
I've not seen a HUGE variety of different drives, but...just sayin'.
-Dave
--
Dave McGuire
Port Charlotte, FL
This is
similar to the 9/7-track reading device: there are no takeup
and feeder reels as they are normally present in a working drive. The
tape is not pulled over the read head under tension.
Do you mean the system used in vacuum-column 7/9 track drives? (I
think IBM used a pinch roller on either side of the head; CDC used
vacuum capstans. The tape columns were kept at the appropriate level
by a photocell system, with each reel motor activated as necessary to
keep an adquate supply of tape in the columns for buffering.