Looking to read past EOT on DDS/DLT/LTO

Chuck Guzis cclist at sydex.com
Fri Jan 27 18:22:42 CST 2017


On 01/27/2017 03:41 PM, Stan Sieler wrote:

> My recollection is that DDS-1 (and perhaps -2?) had 'set marks' that 
> few people knew about, and even fewer ever used.  The explanation I
> recall is that the drive could do a "forward to next setmark" *much* 
> faster than "forward to next EOF".  (BTW, when reading, a setmark was
> reported like an EOF (although if you requested extra status you 
> could tell them apart).)


I believe that ANSI refers to them as "partitions", IIRC, defined by a
special page in the MODE_SELECT command. Each partition has its own EOD.

Using the MODE_SENSE code page 11h will turn up information as to a tape
bing multi-partitioned.

Few people made use of the partitioning feature, as far as I know.

All of this is doubtless covered by one or several ANSI X3B5 pubs.

--Chuck


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