Disk Set 18

[Tom Droege <tdroege@veriomail.com>]

As Michael has reported, there have been some problems in duplicating the 
disks for set 18.  There seem to be some sick tracks.  I only spot checked 
the disks.  There was only once that I had a write failure that the system 
told me about.  So I assume it always read the source disk correctly.  The 
problem seems to be on writing.  I just assumed a read after write check 
but perhaps this is not done with a CD write.

Some of you volunteered to help me make copies.  Perhaps now you can trade 
among yourselves to get good copies to those with problems.  I would like 
to get back to checking out systems.  My guilt is also building up for not 
testing Rob's last software.  Sigh!

The project of the day is writing up a test sequence so that Dan can check 
out the various boards.  This should also be useful diagnosing problems 
when a system fails.

TOM has not has the failure since I installed the oscillation damper 
networks on the input amplifiers.  I am beginning to think this is a real 
fix.  If so, this is good news as it has been a problem since day 1.   It 
makes sense as the problem.  I have just never caught the amplifier 
actually oscillating.  Arne and Michael take note.  If you suddenly just 
get junk data, this is something to suspect.  You may never see the problem 
as it is just on the edge of working.  It is not a hard fix to add, just 
100 ohms and 100 pf in series across the input amplifier.  I will 
eventually send out an "official" change.

Tom Droege