[Info-vax] 9 track end of tape (Was: Copying VMS SaveSet Under Windows)

[Alan Frisbie]

On 11/23/2010 6:48 PM, glen herrmannsfeldt wrote:

> The usual S/360 tape drives have a "Read Backwards" channel
> command that will read the block while moving the tape backwards.
> The program supplies the address of the end of the buffer,
> and the drive fills the buffer from the end toward the beginning,
> such that the data ends up in the right order.  There are sort
> algorithms optimized for "Read Backwards" to avoid the rewind time.

Wow, I never knew that.   I wish I could go back 40 years and
show this to the programmer.   It would have made life a lot
easier!

Alan