Re: 9-track tape drive (Was: Re: versioned filesystems in linux)

[John Bradford]

> > > actually measure the real speed you can presumably vary the speed
> > > arbitrarily, all the way up to the breaking point of the medium.
> > 
> > I suspect that method is patented, as I have seen this implemented on
> > both Travan tapes, and cassette tapes.
> > 
> > However, there seems to have been a flaw in the implementation, where the
> > breaking point was underestimated.
> > 
> 
> Presumably any patents on this have since long expired (they would
> have had to have been filed no earlier than 1983.)

Using two heads, you should be able to write at variable speed as well
- if the heads are spaced two blocks apart, whatever speed you read a
block at with the first head, you could write the new data using the
second head at the same speed.

As long as the tape is formatted correctly, it should work.

John.