[Spock@SAMSON.cadr.dialnet.symbolics.com: IFU]

[Spock <Spock@samson.cadr.dialnet.symbolics.com>]

Snail Mail Address: American Microsystems Inc. (A wholly owned
		    subsidiary of Gould Inc.) CAD Research Lab. P.O.
		    Box 967 Twain Harte, CA  95383
Phone Number:       (209)586-7422

Date: Thu, 1 Dec 88 10:14 PST
From: Spock <Spock@SAMSON.cadr.dialnet.symbolics.com>
Subject: IFU
To: slug@sch-vermithrax
cc: spock@SAMSON.cadr.dialnet.symbolics.com, slug-liaison@sch-vermithrax
Internet Address:   KMA%samson.cadr.dialnet.symbolics.com@riverside.scrc.symbolics.com
Snail Mail Address: American Microsystems Inc. (A wholly owned subsidiary of Gould Inc.)
                    CAD Research Lab.
                    P.O. Box 967
                    Twain Harte, CA  95383
Phone Number:       (209)586-7422

I have an old 3600 that had been upgraded(?) with an IFU board about a
year ago.  This was a fairly painful task which took a lot of time and
board swapping until the machine worked right.  The machine's
performance was noticeably better and I thought things were stable.
However, recently the machine has been flying into the debugger on some
*very* low level errors like wrong type arg to rplacd and illegal
address.  The wrong type arg errors can be continued from by using C-M-R
on the frame that is first presented when entering the debugger.
There have even been occasions of leaping into the FEP where I find:

  "IFU error status: Hit in both map A and map B"

It seems that the occurence of these errors goes down if I raise the
temperature in the computer room (maybe I'm hallucinating).

Soo, what I was wondering was, are there symbolics machines out there
that use the IFU and are reliable machines?  What is the general
consensus of the SLUG community about the IFU board?  Did I just have a
"lemon" experience or should I try to get my old MC board back?  I
really don't want to repeat the "IFU board-swap" fiasco of a year ago
unless it's worth it.