recovering cartridge tapes (was: Tek fiches found!

[Dave McGuire]

On 7/19/10 6:37 PM, Chuck Guzis wrote:
>> 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.

  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