TU56 Tape Heads

[Paul Koning]

> On Jul 25, 2016, at 8:03 PM, Michael Thompson <michael.99.thompson at gmail.com> wrote:
> 
> During our PDP-12 debugging today we found that the left tape head has an
> open coil for data track 0. The left head was OK a little more than a year
> ago when we found the open coil in the right head. One TU56 head on my
> personal PDP-8/e also had an open coil when I got it.

DECtapes record everything twice (5 logical tracks, 10 physical tracks).  Are there 10 coils or only 5?  If 10, does the redundancy work well enough?

	paul