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From: cn0h+@andrew.cmu.edu.UUCP
Newsgroups: comp.sys.cbm
Subject: 1581 Disk Drive
Message-ID: <QVKQZBy00W0Iy8Y0az@andrew.cmu.edu>
Date: Thu, 24-Sep-87 21:39:25 EDT
Article-I.D.: andrew.QVKQZBy00W0Iy8Y0az
Posted: Thu Sep 24 21:39:25 1987
Date-Received: Sat, 26-Sep-87 14:38:29 EDT
Organization: Carnegie Mellon University
Lines: 26


I've been playing with a 1581 drive for a few months, and I love it.  Here
are some interesting things I have discovered:

1) 1581 burst speed is about 8 times 1541 speed, and 1571 burst speed is
about 6 times 1541 speed (for loading only). For file load, it is
surprisingly easy to program with a C128.

2) The 1581 seems not to need "Inquire disk" before a burst access. "Inquire
disk" is absolutely necessary (except when just turned on) with a 1571 disk
drive - it seems to use a hardware flag which can only be set by "Inquire
disk".

***3) Strange chunks of data have been chopped off the end of large files I
have saved on the 1581 drive.  Has anyone else had a problem with this?  It
seems to chop off around line 370 on my wordprocessor (370x80 bytes) - is
this a <<major>> bug?

4) If anyone wants to make a 1581 read Amiga disks (which should be easy) be
sure to worry about the hash directories & file data hunks (which are a pain
in the neck!)

5) The subdirectories are wonderful - if anyone is interested in an automated
BASIC program to create a subdirectory givin the desired size, let me know.

  Chris Newman