[Info-vax] VAX VMS going forward

[Scott Dorsey]

=?UTF-8?Q?Arne_Vajh=c3=b8j?=  <arne at vajhoej.dk> wrote:
>On 7/25/2020 9:46 AM, Scott Dorsey wrote:
>> =?UTF-8?Q?Arne_Vajh=c3=b8j?=  <arne at vajhoej.dk> wrote:
>>> I also suspect that the actual recovery rate may turn
>>> out somewhat less than 100% if attempted to read them all.
>>> Bad tapes, bad tape drives etc..
>> 
>> My experience with nine-tracks is that there is nearly a 100% recovery
>> rate.  Occasionally I'll come across 3M Black Watch tapes that need special
>> processing, but for the most part one cleaning pass and they read through
>> fine.
>
>If the tapes were 5 years old, the tape drive was 5 years old and
>the tape drive was used every week, then I would expect nearly 100%
>as well.

I'm talking mostly 1970s and 1980s tapes.  Most of them stored under office
conditions.  Occasionally I get older tapes and newer tape and the occasional
attic-stored tape.

And yes, I have a well-maintained Kennedy drive that is kept cleaned and
lubricated.

>But I suspect a lot of very old tapes, very old tape drives and
>tape drives that has not been used for years.

If you don't keep the drive maintained, it won't work.  The nice thing about
nine-track drives is that everything is pretty much made with standard parts
available off the shelf.  Also the mechanical part isn't very fiddly.   This
makes it much easier to keep a 9-track drive well-maintained and reliable than
a TK-50.
--scott
-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."