Promptness, queueing, diskless etc. etc.

[William S. Frantz]

> Perhaps more important, given your concern about interrupts, is that
> growing the disk transfer size may lead to *more* interrupts rather
> than less, because a greater percentage of disk pages will span
> multiple tracks.  Such multitrack pages need to be read in multiple
> operations, requiring multiple interrupts.

Multitrack operations on IBM disks do not require an interrupt to 
switch tracks.  My reading of the SCSI standard indicates they don't
need extra interrupts either.  (Both SCSI and IBM-FBA disks treat
disk reads/writes as a stream of fixed size blocks.)

What do IDA disks require?


> The problem lies in the definition of "depend."  If a domain holds a
> start key to a dead domain, is that domain considered dead?  How does
> one indicate "precious" domains that should *not* be considered dead
> under these conditions?

A start key to a dead domain is a solved problem (it acts like a zero
data key).  Caveat Programmer.  I assume "precious" domains would be
so marked.  I havn't thought much about what authority would be required
to set the mark.

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Bill Frantz                   Periwinkle  --  Computer Consulting
(408)356-8506                 16345 Englewood Ave.
frantz@netcom.com             Los Gatos, CA 95032, USA