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From: roadman@portia.Stanford.EDU (arthur walker)
Newsgroups: comp.sys.amiga
Subject: Re: Should I buy a cheap SCSI tape drive?
Summary: 3M tape drive block size 8196 bytes
Message-ID: <8424@portia.Stanford.EDU>
Date: 20 Jan 90 19:51:58 GMT
References: <5841@netcom.UUCP>
Sender: arthur walker <roadman@Portia.stanford.edu>
Organization: Stanford University
Lines: 13

I see that I left out the important detail about he 3M tapes: at the
SCSI level they are 8k in length.  This means the disk driver strategy 
routine has to block and unblock 8k to 512, which combined with the 
slow random access, means that the driver itself should cache a lot of
data if one's desire is to provide a workable disk-like interface for 
general filesystem applications.  

In the mac world, this is facilitated by the desktop file, which can
be cached - in our metaphor, it probably makes sense to write not just
a driver, but eventually a filesystem that uses 8k blocks.

art walker
roadman@portia.stanford.edu