3 Mar
2014
3 Mar
'14
1:45 a.m.
From: "supervinx" <supervinx at libero.it>
Sent: Monday, March 03, 2014 1:33 AM
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: HP 9000/375, HP9121D and NetBSD
[... snip ...]
I checked it with a multimeter: all odd pins are grounded, and the even
numbered grounded pins are compatible with a SCSI-1 connector.
But... the connector has a reversed notch!!!
I mean that pluggin' a standard notched SCSI flat cable connects pin 1
to pin 50. This is confirmed lookin' on the bottom of the board, where
pins are numbered...
That happened to me too! Long ago I won an HP 21MX front panel
on eBay. I added a "blinkenlight" Core and I/O board to it using the
50-wire console connection cable. After soldering all wires, I took
my beeper to check that I did everything correctly ...
It was then that I found out that the red strip along the ribbon cable
was *NOT* pin 1, but pin 50 !! I had to start all over again, grrrr.
Till then I always thought that the red stripe (or any marking) denotes
pin #1. Nowadays I do not take that for granted, but check (twice)!
- Henk