[Info-vax] TK50 - this is annoying...

[glen herrmannsfeldt]

Paul Sture <nospam at sture.ch> wrote:

(snip)

> I once met someone who had used DECtapes and he had been very impressed 
> by them in their day, but he was at least 20 years my senior.  IIRC he 
> described some mechanism where they skipped alternate blocks when 
> reading or writing so that the tape speed could be higher, and those 
> skipped blocks were used when the tape was travelling in the opposite 
> direction.

I haven't heard about that but, just like floppy disks, I suppose
you could do block interleaving. As well as I understand it, DECtape
is direct access in the same way floppy disks are, with block headers
identifying the block number.

> The Wiki entry unfortunately doesn't have any dates, but does claim that 
> they were a lot more reliable than disks of the day:

> http://en.wikipedia.org/wiki/DECtape#Technical_details

> "Upon its introduction, DECtape was considered a major improvement over 
> hand-loaded paper tapes, which could not be used to support swap files 
> essential for practical timesharing. 

(snip)

-- glen