In [EMAIL PROTECTED],
on 06/30/2008
at 03:32 PM, Bass, Walter W [EMAIL PROTECTED] said:
I was a young lad I would watch (and listen) most intently as my father
would frequently open up the back of our tube TV to effect repairs. I am
quite certain that I recall hearing a steady background hum
There is an excellent book on Lyons and the LEO computer system called
A Computer Called LEO. I'd recommend it to anyone.
(watch the wrap)
http://www.amazon.co.uk/Computer-Called-LEO-Worlds-Office/dp/1841151866/ref=sr_1_1?ie=UTF8s=booksqid=1214912651sr=8-1
---snip
Shmuel Metz (Seymour J.) wrote:
I was a young lad I would watch (and listen) most intently as my father
would frequently open up the back of our tube TV to effect repairs. I am
quite certain that I recall
On Sun, 29 Jun 2008 19:43:08 +0200, Thomas Berg
[EMAIL PROTECTED] wrote:
...
http://seattletimes.nwsource.com/html/localnews/2008023617_camin
erobit29.html)
...
Certainly no reflection on Mr. Camimer but that Seattle Times article
would have been a bit better if it had not said:
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Patrick O'Keefe
Sent: Monday, June 30, 2008 2:22 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: David Caminer (1915-2008)
On Sun, 29 Jun 2008 19:43:08 +0200, Thomas Berg [EMAIL PROTECTED]
wrote
No, the writer is quite technically astute and meant that the vacuum
tube circuits with their chokes, coils, etc. were ELECTRICALLY noisy.
But knowing that their audience wouldn't have a clue (as the editor
didn't either) and so cut all that out so that it just said that the
vacuum tubes were
On Mon, 30 Jun 2008 15:30:58 -0400, Thompson, Steve
[EMAIL PROTECTED] wrote:
...
No, the writer is quite technically astute and meant that the vacuum
tube circuits with their chokes, coils, etc. were ELECTRICALLY noisy.
...
You may be right. You are definitely giving the author more credit
--snip
Noisy vacuum tubes? Vacuum tubes had a number of drawbacks
but I don't recall their being particularly noisy. I can only assume
the original models either had a bunch of clattering relays, or
noisy cooling systems.
-snip
No, the writer is quite technically astute and meant that the vacuum
tube circuits with their chokes, coils, etc. were ELECTRICALLY noisy.
But knowing that their audience wouldn't have a clue (as the editor
didn't either) and so
--snip
Tubes can be VERY noisy, electrically. Even if they're
virtually silent
when you're standing there listening.
--unsnip
I was a young lad I would watch (and listen) most
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of Bass, Walter W
--snip
Tubes can be VERY noisy, electrically. Even if they're virtually
silent when you're standing there listening.
-Original Message-
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Patrick O'Keefe
Sent: Monday, June 30, 2008 3:13 PM
To: IBM-MAIN@BAMA.UA.EDU
Subject: Re: David Caminer (1915-2008)
On Mon, 30 Jun 2008 15:30:58 -0400, Thompson, Steve
[EMAIL PROTECTED] wrote
--snip
I remember my first (and last) radio kit emitted a barely audible
high-pitched whine when turned on. The only other detail I remember
--unsnip
Now you're making a connection
--snip
I remember my first (and last) radio kit emitted a barely audible
high-pitched whine when turned on. The only other detail I
remember
--unsnip
[CLC] my guitar amp is full
Now you're making a connection back to the original article. That
high-pitched whine was from high frequency magnetic fields causing the
internal ferrous parts of the tube to vibrate. This would sometimes be
at harmonic frequencies that would cause the external tube or even the
mounting
Last post of mine on this subject, hopefully...
But the big difference is, lots of voltage = large electromagnetic
field. Low voltage with low amperage = small electromagnetic field.
Tubes use large voltage differences, solid state uses small differences.
It all boils down to noise margins.
If you have an old amp with tubes, try this - just very lightly tap the side
of the tube with a pencil, and hear what sounds like a Chinese gong being
struck.
When I went to the University of Waterloo, in the mid 1970's, I had a professor
who did his masters at MIT.
They had a vacuum tube
Thompson, Steve wrote:
I don't remember what vacuum tube logic circuits looked like. Are you
sure they were much noisier than the transisterized circuits that
replaced them?
I never saw the tubes in the earlier machines, except in
pictures, but the last tube generation used any of a family
When I went to the University of Waterloo, in the mid 1970's, I had a
professor who did his masters at MIT.
They had a vacuum tube computer that had all its tubes mounted on both walls
of what was basically a 6-metre corridor.
Somebody would have to go in everyday and run the erasor end of
On Mon, 30 Jun 2008 14:21:46 -0500, Patrick O'Keefe
[EMAIL PROTECTED] wrote:
...
Certainly no reflection on Mr. Camimer but that Seattle Times article
would have been a bit better if it had not said:
...developed two more generations of LEO, the last with transistors,
rather than the noisy
The Lyons Corner Shops predeceased him, and David Caminer has now joined them.
One of the principal designers of LEO, the first business computer, he was a
programmer of genius and an anomaly: Think, as a British obituary writer
suggested, of McDonald's designing the Internet to get some
As it was very interesting reading for me and, I think, for others, I
here citate
from an article (
http://seattletimes.nwsource.com/html/localnews/2008023617_caminerobit29.html
):
By DOUGLAS MARTIN
http://search.nwsource.com/search?sort=datefrom=STbyline=DOUGLAS%20MARTIN
The New York
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