[Info-vax] TLZ7

[Bob Koehler]

In article <iaugng$18n5$1 at ns.felk.cvut.cz>, smithfarm <presnypreklad at gmail.com> writes:
>> 2GB uncompressed makes it a TLZ04, DDS-1. TLZ07 does 4GB uncompressed
>> and is DDS-2. Some inconsistency here, not sure who to believe. The
>> hardware is usually definitive.
> 
> Is the only way to tell DDS1 from DDS2 (definitively, from the hardware) 
> to attempt to write more than 2GB to a DDS2 tape and see what happens? 
> Or is there another way?

   There are also tape lengths written on most of the cartridges.  I've
   been told that some drives built for 60m tapes can be damaged by
   90m or 120m tapes, so I avoid doing that, but I've never actually
   had a problem.
   
   Obviously a 90m tape should hold about 50% more than a 60m tape in
   a drive that handles both.  Turning on compression can make a bigger
   difference, depending on the data.