< It's possible to make transistors with not too complex equipment
It's trivial. All you needs is some crystal pure germainium and two
gold wires. The wires will be placed ajacent to each other without
touching and in contact with the chunk of germainium. To that apply a
pulse of current to each wire to cause localized heating and hence
contact doping. Test your transistor. You will find it noisy, leaky,
slow and exactly the same as the Bell labs proto!
congrats, you have succeeded. You can now continue on to grown junction,
alloy, diffused and then silicon based devices. Junction FETs will come
later after you have figured how to get planar diffusion technology.
Allison
> It's not that weird. Everyone knows that 286 and 386 machines are
> crap ;) In fact, one reason is that noone gets attached to them, and
> also because Pentia aren't that much different from 386s. So, no
> nostalgia. And, I think that early PCs were a lot less useful than
> some other machines of the time (like Commodores and Apples)
Just tell these to some of the Yougoslavian dealer
on swap meets and fleamarkets over here they are
mostly ignorant and see PC as PC - no mater whats
inside. 86 laptop with broken case just 200 Mark
(as seen last weekend :) WooHaHa.
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
______________________________ Reply Separator _________________________________
Subject: Re: CRT decay
Author: classiccmp(a)u.washington.edu at internet
Date: 11/2/98 12:00 PM
At 11:41 AM 11/2/98 -0500, Marty wrote:
>
> Sounds like you may be talking about a 'getter' which is used in the
> production of vacuum tubes (valves for you gents across the pond) to
> eliminate vapor and residual air the vacuum pump can't draw out or may
> be in the metal components of the tube (plate, grid, filiment and
> arbor). The getter is a compound (barium, magnesium, etc.) placed in
> the tube which is ignited after the envelope is sealed. After the
> getter ignites it sometimes leaves a silver coating inside the tube.
Yes, "getter" is the word. The substance I remember would generate
an ozone-smelling gas when wetted. It physically resembled calcium
carbide in color in appearance.
>>Offhand, I'm not sure how this coincides with your description of an
>>ignited compound: you'd think there wouldn't be much oxygen there
>>at that point in manufacturing, and what combustive process would
>>*release* free metal?
From what I've read there are traces of oxygen actually in the metal
parts, plus the vacuum pumps cannot draw all residual gas from the
tube. The getter flashes and literally burns the residual gases from
within the tube and the metal components. A byproduct is the
silvering on the inside of the tube. I can look up the process and
give you more details if you wish. I have a 1935 book entitled
'Theory of Vacuum Tubes in Radio' which goes into great detail on the
matter. It explains the various getters and why they were introduced
in manufacture along with the chemical makeup of the getters.
Marty
- John
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From: John Foust <jfoust(a)threedee.com>
To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
Subject: Re: CRT decay
In-Reply-To: <1998Nov02.114008.1767.155220(a)smtp.itgonline.com>
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Oh, come now... B^} The king of gear moving is (and probably will remain
for some time) Paul Pierce (keeper of the mainframe collection).
Estimated to be around 75 TONS in overall weight (as noted in a Wall Street
Journal (!) article on Friday), Paul has moved the entire collection at
least three times that I can think of, before it arrived in its current
(permanent) home.
Some might want to have a look at the WSJ article. It also features quotes
>from a number of names that most will be familiar with. Its (the article)
easy enough to find... it begins on the front page!
-jim
---
At 10:19 AM 11/1/98 +0000, Pete wrote:
>
>On Sun, 1 Nov 1998, Computer Room Internet Cafe wrote:
>
>> I thought I did well moving a Vax 8530/6310 cluster, complete with
>> 2 HSC50's, TA78/TU78 and about 15 RA8x and some RA7x drives from
>> a warehouse to my parents house, then getting it up a narrow gap into a
>> vacant granny flat. Over gravel.
>> But we did have a forklift load it on the vehicle for us.
>>
>> I think the PDP effort beats that one.
>>
>
>What about my uVAX II? I collected it from the 2nd floor (3rd floor in
>US terms I think), 2 of us carried 2 RA81s and the 19" rack unit down a
>steep, narrow, winding staircase and the out through the owner's garden
>before loading it all into a medium six UK hatchback (Vauxhall Cavalier).
>My other 3 RA* drives came from an old established University down even
>narrower staircases. At this end I cheated, as I was moving them on my
>own by then I brought them into the house by wheelbarrow :)
>
---
jimw(a)agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
At 10:09 AM 11/1/98 -0800, you wrote:
>On Sun, 1 Nov 1998, Max Eskin wrote:
>
>> It's too bad most micros don't have a debugger in ROM. Except for
>> computers made by Apple, I don't know of any. I especially wish the
>> PC had a ROM debugger. It would really help me feel like I'm using a
>> worthwhile machine.
>
>Boot DOS (or open a DOS window). Type "debug". Not in ROM but its what
>you want.
The Zenith PCs have a good ROM based debugger that works very similar to
debug. Press Control, Alt and Insert simultanously. It'll put you into the
ROM based system monitor. It Type ? for help.
Joe
>> What is this CRT from again?
> It's a 30-year old CRT from a 30-year old computer. The surface is glass,
> AFAICT.
30 years ? That's not realy old - I had think of maybe
50 years, since I know special cases of degradiation
of old tubes from around the war, especialy when stored
in very dry (less than 60%) and warm (average 25 C)
conditions. But all of this doesen't affect the glass.
'Only' the coating around the tube (to keep light out).
and inside of the tube (sometimes additional coating
and of course the phosphor layer at the projection
screen).
The coating on the outside is often just turned to
dust on tubes of this or greater age, since they
didn't use any kind of ceramic material - often
just special kinds of paper, that turns out to be
very teperature and heat sensitive. When these
coatings have been kind of hard, they also suffered
>from the expansion of the tube.
The coatings on the inside had only the teperature
and mechanical problems, and seam to be very stable
when stored properly and not to warm (I know TV sets
still working after 50 years!). But when exposed to
heat, the inner coatings also degenerate. I have seen
complete clear Braun tubes ... just some dust in one
corner...
Gruss
Hans
--
Ich denke, also bin ich, also gut
HRK
Actually, the machine is less for my personal use as it is for posterity.
My
goal is the creation of a museum of such computers, so that our posterity
will not soon forget the nature of computers in the 1970's, perhaps into the
60's. I doubt that I shall ever get a chance to obtain machines like the
7090,
1620, and 1401 (all IBM). Nor will I likely obtain ENIAC. Yet, there is
still
time to salvage and restore many mainframes, machines which will never
again be graced with production runs, fresh Hollerith cards, etc. These
first
and second generation electronic digital computers are clearly antiques,
and the processors of our day will soon join them in history. That is what
a museum is all about. Remember, those who forget the past are doomed
to repeat it!
William R. Buckley
-----Original Message-----
From: Mitch Wright <mew_jac(a)swbell.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, November 01, 1998 3:44 PM
Subject: Re: PDP-11/44 boot prompt
>So what are you personaly going to do with 30' of rip roaring PDP-11/44
>and diskdrives?
>
>--Mitch
>
>> Are you certain of that? Cray designed the CDC 160, and had a hand in the
>> CDC 6000s, but I do not think the STAR.
Seymour Cray had more than a hand in the design of the 6000 series.
Although he worked with some fine engineers (Thornton (sp?) is one name I
remember), I believe that the instruction set, architecture and packaging
scheme all primarily came from Seymour.
>After more than 25 years, I am not certain of anything. But if Cray had a
>hand in the CDC 6000s, and he was still around CDC at the time the
>STAR 100 was designed and built, I would certainly think that he was
>also involved in the STAR 100 as well.
As I remember (I was working on CDC's mainframe products at the time, not
the STAR), the STAR's were done by the people "left behind" after Seymour
left. As such, there was an unspoken agenda to the effort: The engineers
were trying to prove that they were just as good as Seymour, and the
executives were trying to prove that letting him leave wasn't a mistake.
>I thought I saw an article about
>the STAR 100 recently which described the circular nature of the physical
>rack which was required in order to reduce to length of the wires which
>interconnected the different parts of the system.
Again, I'm not positive about this, but I think that the STAR's that I
walked past on the test floor were in conventional rectangular boxes.
----
John Dykstra jdykstra(a)nortel.com
Principal Software Architect voice: +1 651 415-1604
Nortel Networks fax: +1 612 932-8549