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From: Ordania-DM@cup.portal.com (Charles K Hughes)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Two Questions
Message-ID: <37340@cup.portal.com>
Date: 29 Dec 90 02:37:44 GMT
References: <20892.277b4029@merrimack.edu> <37329@cup.portal.com>
Organization: The Portal System (TM)
Lines: 26

Chris asks about 1050 vs Percom autobooting and about SIO problems...

   The Percom (to my knowledge) does not work with "Enhanced" density
disks.  These are the disks that hold 128k (1000+ sectors) instead of the
90K of single density.  I know you said the disk was single density, 
but you might want to check again to make absolutely sure.  The easiest
way to check is to use a disk editor program and try to read/write sector
721 - don't just look at the DOS structure on the disk, this isn't reliable.
If the disk absolutely, positively is single density, then my next guess
is that you are using a commercial software disk of some kind that has
a nasty form of copy protection on it.  The Percom does not act exactly like
a 1050, 810, or XF551 and might fail copy protection checks.

   SIO problems are a bitch.  If swapping cables doesn't have any effect,
swap positions of the SIO units.  So, connect computer to D2: to D1: to 
(something else) and test the something else.  If the something else fails
then the SIO connector is indeed at fault.  To find out which connector is
at fault just swap the incoming SIO cable on D1: to the outgoing SIO
connector on D1:.  If D1: fails, then the incoming SIO connector is bad,
if it doesn't fail AND the something else does fail, then the outgoing
connector is bad OR both connectors are bad.  In some Atari peripherals
the SIO connectors were only soldered in and not screwed down.  Check 
inside the drive, and if this is the case, replace both SIO connectors just
to be on the safe side.

Charles_K_Hughes@cup.portal.com