On 2/3/21 10:18 AM, Paul Koning wrote:

Fair enough, but that means your real time processing needs to be sufficient to 
know where the tracks are.  And if the media are in bad shape, you may in fact 
want to capture each track N times at slight offsets from the nominal position, 
then do signal processing to recover the data as best you can.


That is in conflict with the requirement you spend as little time as you can on 
shedding media
ideally, you'd use a 96tpi drive on 48tpi and microstep the head positioner. 
you still have the
problem of head clog.

And, AFAIK, no existing software does any of this.

Come to think of it, the techique of reading 1/2 inch tape with 36 track MR 
heads is somewhat similar: you get multiple readings of the same nominal data 
track and can use the additional data to help with recovery.

In practice, the channels smear together, that's why John Bordynuik went to 36 tk 
3490 heads from 18 tk 3480 heads on his 1/2" tape setups.

We saw this as well on the 6-track Whirlwind tapes using a 9-track head. 
Fortunately 6 of the heads lined up cleanly.



Reply via email to