mdc@spt.entity.com (Marty Connor) (12/21/87)
I have a few questions about 386 hardware incompatibilities.
The Tale:
Wanting to find out what sort of performance difference I could expect
between a 386 machine and a 286 with an above board, I bought the
following:
- A GeNuinE Intel Above Board[tm] for a Compaq/286
- A geNuiNE Wyse 386 box, with 2 meg of ExcItinG 32 bit memory
Now on each of these machines I put the following two cards (as I have
used them on my 286 boxes with great success):
- One GeNuInE 4 meg Intel Above Board
- One gEnUinE Digiboard 4 port dumb serial card
Now, I loaded SCO Xenix 2.2 for the 386 on both of these beasts and
interesting things started to happen. First the Wyse complained about
the infamous MULBUG. I couldn't believe these Wyse folks were STUPID
enough to ship 386 boxes with GeNuInE Intel chips that said on them
"FOR 16 bit SW only"... So I screamed at the distributor and they
sent me a geNuinE Intel 386 chip that could multiply properly.
The inboard seemed to work fine in the Compaq initially.
Then the fun began. Memory tests on the Wyse FAILED on powerup. I
fiddled with the Above Board software. I fiddled with the the dip
switches. I called Intel for some GeNuiNe advice. The said, "well,
the above board has worked on a number of 386 systems...".
So I decided to ignore the memory test, since, after all Xenix could
SEE all the memory, and bad things weren't yet happening. Next I
discovered that Digiboard wasn't working. Suspicious, I said. So I
went back to the GeNuINE Wyse SETUP program and slowed the machine
down to 8 Mhz, and suddenly the machine stopped crashing with "Memory
Parity Errors", and the Digiboard worked, and all was right with the
world for the most part. Except the machine was running ...slowly...
Question #1 (for 10 pts):
Why the HELL doesn't the GENUINe Above Board work when the clock(?)
speed is 16 Mhz? Isn't the BUS Speed the important thing, and isn't
that 8mhz? Faster chips usefuL here?
Question #2 (for 10 pts and a chance at the bonus round):
Why doesn't the Digiboard work at 16mhz? Is it possible Wyse is,
doing something ... non-GeNUiNe?
Question #3 (for 15 points)
Background:
The Compaq worked mostly at 12Mhz (as selected with a Motherboard dip
switch; That is the memory diagnostics passed, and the Digiboard
worked, but every few hours there would be a dreaded "Memory Parity
Error". Switching to 8Mhz seems to cure this problem.
Query:
Would putting fast Ram Chips on the Above Board help this?
What does the motherboard switch actually set?
Question #4 (Extra Credit, 5 points)
A: Are there any dumb cards that work with a 386 and can keep up
at 16 Mhz? The Digiboard seems unable to.
B: I have some GeNuinE (<==note StuDly CapitAlIzatioN) Arnet
Smartboards, which claim to be ROCK SOLID, and come with 386
drivers and everything. Has anyOnE driven these things
at high speeds and won big??
C: Does anyone have KCL running on a 386 under SCO Xenix?
(trick question)
Question #5 (for the GraNd PrIze (no kidding.))
Describe the hardware for an ideal 386 development system with 6
megs or memory, 8 serial ports, 60 meg disk. I am leaning towards
the Compaq/386 since Compaq seems to "just work better".
Argue for and/or against this idea.
======= Prizes ========
The most helpful person(s) will receive a set of floppies containing
GnuEmacs 18.49 for SCO Xenix386, with shell buffers and unexec()
working, which means it starts in UnDER 10 SECS(!) even on a crippled
8mhz 386 box. The implications of unexec is that the emacs is dumped
with libraries and so loads much faster than a version that must load
libs at startup since it is largely in core already. And of course
since you get the SOURCE to the Emacs, you can actually FIX things (or
read real code and learn something).
Disclaimers:
- I have a strange sense of humor, and am mainly doing this to attract
interesting females who hack and like to talk.
- All prizes WILL be awarded at the descretion of our judges (moi).
- Employees of The Consulting Entity (Entity.Com) (and main sqeezes thereof
are not eligible.
- I have a cold, but it's almost gone.
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