Diffs 3B1/7300 - Conversion

[Ed Horch]

Speaking of RAM upgrades...  I purchased two megs of Samsung 150ns
DRAM, figuring on putting one in the other half of the motherboard
(I have 1meg installed), and the other meg into the Combo board.
Well, I put the RAM in the Combo board, and the diagnostics gave
all sorts of terible complaints.  Of course, since the diagnostics
aren't documented beyond pass/fail (grr), I couldn't tell which specific
parts were failing.  But, when I had the RAMs tested, they all passed!

Craig Votava told me:

>A buddy of mine said that different memory chips offer different resistances
>when current is put through them. The resistor packs on the board are there
>to "even" the resistance out to a known value, so the packs that are there
>are designed for the type of memory that the designer used. Sometimes, in
>order to use chips that have a different resistance than what was designed
>for, the resistor packs need to be changed. 

Anyone have any more info on this?  I'd also be deeply indebted to anyone
who could tell me more about reading the diagnostic outputs.  (Oh yes, 
and the generic "add me to the list" to anyone who has succesfully added
a second hard disk, or 1.2Mb floppy and wants to brag about it.)

I've just about given up on the idea of adding the other meg to the
motherboard.  I just don't feel comfortable doing all that soldering on
a board that will cost me as much to replace if/when I screw it up, as
the whole machine cost when I bought it.  I'll use the other meg in
another machine, probably the Amiga I plan on buying pretty soon. 

Back to the original subject line:  I know the complete 7300 -> 3B1
conversion kit is hideously expensive, but does anybody have pricing
info for just the enclosure upgrade, i.e. the top cover, pan cover,
video cable, etc.?  I'd sure like to get my Miniscribe 6085 into the
box.   (BTW, for those of you considering this drive, I highly recommend
it.  It has run flawlessly 24 hours a day since November, through many
nasty power problems.  [110V?  Yeah right, maybe on *average!])  My
only complaint is that head movement's a little noisy.  And yes, you
do have to use the cable directly off the power supply.  I tried using
the cable off the motherboard and it didn't work.

Oh, and one last little hint for those of you running full netnews
on your 3B1:  The news software keeps history information around for
as long as the oldest article.  If you don't use the -I option of
expire, this will result in several weeks' worth of history info
being kept around due to the long Expires: dates in comp.mail.maps
postings.  The 2Mb of history info is only a minor annoyance in terms
of disk space, but it really slows down rnews processes, increasing
the time by a factor of three over having three days' worth of history.

What I use is a little shell script that  a) does a general 3-day
expire without the -I option,  b) polls my feed sites for news, 
c) runs uuhosts -unbatch and pathalias to update the paths file, and
d) does a one-day expire of comp.mail.maps *with* the -I option.  I'd
normally use a zero-day expire, but I want to keep the last day's 
input around in case something breaks.  If there's sufficient interest,
I can post this to unix-pc.sources.  (I'm currently working on a mod
to this script that handles failed polls better.)

Well, we know that the 7300/3B1 has been discontinued :-(, but what's
the status of the version Convergent markets?  Is this still a Real
Product, or are they just supplying parts for 7300/3B1's (as their
agreement with AT&T says they will for a few more years)?

-Ed Horch    argon!ebh     Some day, my Trailblazer will come...