Ancient disk controllers - test-drb@ccmp.vtda.org

17 Apr 1999

I've got one or two of these DAVONG controllers, as well as some of the
documentation.  I bought them as spare parts for the Western Digital
controllers I liked better.  Since they had the 8X305 and the requisite
current injection valve transistor (don't ask me about that!. . . it's
characteristic of I2L logic, I'm told.) and similar varistors, I thought the
couple of bucks for the controllers was worth it.  I bought the boxes and
supplies for useful applications, though the boxes were odd enough never to
find them.

If you have questions, I may be able to help, but I've never read the doc on
these so be patient.

Dick

-----Original Message-----
From: Ethan Dicks &lt;ethan_dicks(a)yahoo.com&gt;
To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
Date: Saturday, April 17, 1999 6:18 PM
Subject: Ancient disk controllers

...

The recent postings regarding old disk controllers has caused me to dig out
one I got at Dayton many years ago.  I bought it for the external box,
something I didn't have at the time... it appears to be a SCSI card, but
might be a SASI card.

It was made by Davong Systems, Inc., a company I remember from my younger
days.  The copyright is 1982, but there are chips on it from 1983.  On the
back are numbers like 0034 REV (J1) K 310026 170.  The J1 is scratched out
and the K handwritten.  The 170 is also handwritten.  On the long end in
copper is the number 11-000034 REV E.

Connector J2 and J1 are together on one side of the long end (J1 is 34-pins
with half of them grounds, J2 is 20 pins with pins 2, 4, 6, 8, 12, 16 and 20
...
 grounded).  J3, J4 and J5 are in line on a short end,
20 pins each, similar
ground pattern to J2.  J2 through J5 appear to have connections to a Motorola
...
 AM26LS32 and a TI AM26LS31 which I take to be some sort
of analog chip.
The final connector, J6 is 50 pins.

J1 appears to be the control cable for an ST506 drive, J2-J5 appear to be
data cables for talking to four drives.  The interesting chips on the board
include a N8X305N processor, some N82S181N ROMs, an N8X371N with leads going
...
 right to the 50-pin connector, and five socketed WDC
parts copyrighted in 1980:
...
 WD1100V-03, WD1100V-01, WD1100V-04, WD1100V-05 and
WD1100V-12.  There is a
crystal at 20Mhz in the analog section of the board and an 8Mhz crystal by
the processor.  In the middle of the board are three vias that are labelled
as if they are configuration pads, in an inverted-L, labelled "1", "2"
and
"3", with a "W" above them,

As I said, I was told when I bought it that it was a SCSI controller.  I
remember trying to use it some years ago and not having much success.  Does
anyone have any info on this oddball?

Thanks,

-ethan

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