17 Feb
1998
17 Feb
'98
12:16 p.m.
Thanks Tim. I checked out the ftp reference you gave. Great site,
I've already started browsing through a bunch of it.
On 17 Feb 98 at 13:03, Tim Shoppa wrote:
That connector that you found is almost certainly the
Molex
connector that DEC used for 20 mA current loop connections. On
older machines, 20 mA was the de facto standard for the console
terminal, as the console terminal was traditionally a Teletype of
some sort.
Yes, I've now decided that the console is set for 20 mA. The second
M7856 with that cable seems to be set for both SLU & LTC active set
for console. Transmiter active, receiver active, reader enabled, 110
baud, 8N2. I haven't looked at the switchs for the other board yet.
All DEC VT-220's came equipped for 20mA current
loop, and it was an
option for the VT-100's and VT-52's. It was also quite standard on
the older DECWriters.
Guess I need to locate a DEC terminal. I have some Honeywell Bull
terminals which emulate a VT100 and a Wyse 50 but nothing with a
connector which matches this cable. Am I wrong in reading this doc
on the board where it looks like it can be configured for RS-232?
Can I reset it and use a different cable instead of the 20 mA?
It's possible that you've got a 240V power
controller, but unlikely.
More likely you have a 120V power controller that originally had a
Hubble 25A Twist-N-Lock connector on it. If you post the model
number of the power controller box, I can find the voltage it was
designed for. Usually this is clearly marked on the power
controller.
I've had a little more time to look over the system. The cut cord to
the power box is real thick and the three wires are a good size too
so I thought it was a 220V connection. Looking a little more closely
at the back of the box I see :
861C UA REVL
Input 120V 50-60 HZ
2 Pole 3 Wire 24A
Until then, you'll find that each of the boxes in
the rack has a
rather standard 120V power plug attached. These can be plugged
straight into whatever you find handy until you get your power
controller plug reinstalled. The 11/34A CPU box itself draws less
than 12 Amps.
I'm still finding out things about this system. There is a DEC tag
on the side of the system with the serial number and such labeling it
an 11/34a and dated 16-Dec-77. Not too long after I first started
programing. Back then though I was on HP boxes.
Ok, I need to locate something to use as a console and have the power
supply checked. Then I'll fire her up and see how it goes. After
that I'll begin work on the drive.
-----
David Williams - Computer Packrat
dlw(a)neosoft.com
http://www.neosoft.com/~dlw