Path: utzoo!utgpu!water!watmath!clyde!att!ucbvax!XEROX.COM!"Hugh_E._Wells.ElSegundo"
From: "Hugh_E._Wells.ElSegundo"@XEROX.COM
Newsgroups: comp.sys.atari.8bit
Subject: XF551 Disk drive
Message-ID: <880815-162514-1059@Xerox>
Date: 15 Aug 88 23:25:23 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 33

8/15/88

Has anyone experienced the XF551 drive going to sleep?  I'm aware of two drives
that periodically fail to respond to the normal boot process.  The SLEEP
syndrome is not like the one exhibited by the old 810 drive which went to sleep
in the middle of an operation.

These drives are attached to different systems and operated by different people.
Once booted, the drives continue to perform normally.  Only the start-up boot
is in question.  The XF551's are attached to 800XL's. 


I'm trying to determine the following:

1.  Whether the XF551 design has a problem.

2.  How frequent does the problem occur?

3.  How it can be circumvented, or how to get the drive to respond while it is
asleep?  Multiple re-boot cycles are usually required for a start when the drive
is acting up.

4.  Any fixes that may have been developed to correct the problem.

5.  Is there a known problem with the 800XL enable voltage level being in the
TTL marginal logic voltage band?

6.  I would also like to obtain a schematic set for the XF551.


Any information you can provide will be appreciated.

Hugh