[Coco] quick question

[Arthur Flexser]

On Thu, 27 Dec 2007, John Strong wrote:

> I always thought that the interleave was set to 4 to allow time for disk basic
> to check for the break key. 

I don't think that would have anything to do with it, since the break key is
checked only between statements, whereas a typical disk operation, such as
LOADM"filename" is a single statement.  The optimal interleave does depend
heavily on just what operations are being performed between successive sector
reads or writes.  I experimented with this quite a bit in writing the fast
backup command that is in Extended ADOS-3.  For that, reading and writing the
sectors in the order they exist on the disk (interleave of 4) was not optimal;  
the fastest backup was achieved by using a different interleave from that for
reading in data from the source disk, and a still different one for writing the
data out to the destination disk.  And if my disk speed was a little below or
above spec, it may well have affected the results.

Art