23 Dec
2012
23 Dec
'12
10:36 a.m.
I'm looking for one or two DEC E2057 (VAX 7700 CPU) modules.
I'd also like to find some CI cables. (the thick blue coaxial cables)
Anybody gots? Please contact me off-list of is.
Thanks,
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
23 Dec
23 Dec
1:20 p.m.
On Sun, 23 Dec 2012 13:36:32 -0500
Dave McGuire <mcguire at neurotica.com> wrote:
I'd also like to find some CI cables. (the thick
blue coaxial cables)
Aren't those just ordinary RG-8/U / RG-213/U style 50 Ohm
koax cables
with ordinary TNC connectors and an extraordinary blue color?
I have some (non DEC) CI cables. They are just TNC terminated blue RG58.
--
\end{Jochen}
\ref{http://www.unixag-kl.fh-kl.de/~jkunz/}
1:34 p.m.
On Dec 23, 2012, at 1:20 PM, Jochen Kunz wrote:
On Sun, 23 Dec 2012 13:36:32 -0500
Dave McGuire <mcguire at neurotica.com> wrote:
Don't know. From what I can remember (I have a bunch of them) they're fairly
thick and heavy.
TTFN - Guy
I'd also like to find some CI cables. (the
thick blue coaxial cables)
Aren't those just ordinary RG-8/U / RG-213/U style
50 Ohm koax cables
with ordinary TNC connectors and an extraordinary blue color?
I have some (non DEC) CI cables. They are just TNC terminated blue RG58. 
10:05 p.m.
Jochen Kunz wrote about CI cables:
Aren't those just ordinary RG-8/U / RG-213/U style
50 Ohm koax cables
with ordinary TNC connectors and an extraordinary blue color?
Guy Sotomayor wrote:
Don't know. From what I can remember (I have a
bunch of them) they're fairly
thick and heavy.
That's certainly consistent with RG-8/U (obsolete) or RG-213/U.
2:56 p.m.
On 12/23/2012 04:20 PM, Jochen Kunz wrote:
I don't know their impedance; they may be 50-ohm. They're definitely
not RG58, though...they are much fatter. Not quite as fat as RG8
though. There's little difference in diameter between the outer jacket
of the coax and the TNC connectors.
They are also semi-rigid, somewhat similar to Heliax but not quite
that rigid.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
I'd also
like to find some CI cables. (the thick blue coaxial cables)
Aren't those just
ordinary RG-8/U / RG-213/U style 50 Ohm koax cables
with ordinary TNC connectors and an extraordinary blue color?
I have some (non DEC) CI cables. They are just TNC terminated blue RG58.
24 Dec
24 Dec
12:43 a.m.
On Sun, 23 Dec 2012 17:56:27 -0500
Dave McGuire <mcguire at neurotica.com> wrote:
I don't know their impedance; they may be
50-ohm.
[...]
The cables I have (not made by DEC) are realy, clearly marked with
"50 OHM CHEAPERNET 10BASE2". I got them with a QBus to CI and CI to SCSI
setup. I handed the CI stuff, with the exception of the cables, to a
friend some years ago. So I can't be more speciffic.
I suspect CI cables are just ordinary 50 Ohm coax, but heavily
overspeced in best DEC tradition. ;-)
They are also semi-rigid, somewhat similar to Heliax
but not quite
that rigid.
I won't call semi-rigid a cable and Heliax is no semi-rigid.
--
\end{Jochen}
\ref{http://www.unixag-kl.fh-kl.de/~jkunz/}
3:55 p.m.
On 12/24/2012 03:43 AM, Jochen Kunz wrote:
Yup. Ethernet cables.
I don't
know their impedance; they may be 50-ohm.
[...]
The cables I have (not made by DEC) are realy, clearly marked with
"50 OHM CHEAPERNET 10BASE2". I got them with a QBus to CI and CI to SCSI
setup. I handed the CI stuff, with the exception of the cables, to a
friend some years ago. So I can't be more speciffic. I suspect CI cables are just ordinary 50 Ohm coax, but
heavily
overspeced in best DEC tradition. ;-)
I agree (now) that they're most likely 50-ohm, but that particular
coax is anything but ordinary. ;) I'm sure they over-specced it like crazy.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
8:31 p.m.
On 12/24/2012 11:16 PM, Alexandre Souza - Listas wrote:
Probably. ;)
Just getting it working isn't the issue; I have one system running via
CI now (a VAX-7000) and I can get others up on the cluster pretty easily
with some other coax. I'm specifically looking for "authentic" CI
cable, though, for a historically-correct setup.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
I agree
(now) that they're most likely 50-ohm, but that particular
coax is anything but ordinary. ;) I'm sure they over-specced it like
crazy.
Newer coax has less losses and a better speed factor. Maybe it was
overengineered to a better spec... 
25 Dec
25 Dec
4:11 a.m.
Irrelevant knowledge: It is expensive as hell in Brazil.
Here, the cheap cable is RG058 (not cellular type) :o(
---
Enviado do meu Motorola PT550
Meu site: http://www.tabalabs.com.br
----- Original Message -----
From: "Eric Smith" <eric at brouhaha.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Tuesday, December 25, 2012 2:37 AM
Subject: Re: VAX 7700 CPUs, CI cables
Alexandre Souza - Listas wrote:
Newer coax has less losses and a better speed
factor. Maybe it was
overengineered to a better spec...
For short distances, i.e., tens of meters
rather than hundreds, RG-174/U
will work fine. It is more flexible and very inexpensive.
Eric
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