Saw this on spamnet news...
----- Original Message -----
From: "Frank Ebinger" <Frank-Ebinger>
Newsgroups: comp.sys.ibm.ps2.hardware
Sent: Thursday, May 01, 2003 12:44 AM
Subject: Germany: Free RS/6000 !
> Hello!
>
> Is anybody near Karlsruhe interested in RS/6000
> Model 320, 340, 360 and some other Models?
>
> Look at the Newsgroup ka.markt.computer
> The University in Karlsruhe offers RS/6000 !
>
>
> Best regards
>
> Frank Ebinger
On May 1, 23:13, Philip Pemberton wrote:
> If someone wants to send me one or two plotters with bad drive gears,
I'd be
> willing to have a go at repairing them. My technique involves
repairing the
> damage with Araldite (epoxy adhesive - sets rock hard) and then
putting a
> small (#10) staple in across the damaged section.
Er, the gear we've been discussing is very small -- about 3mm overall
diameter, roughly the size of the winder knob on a small ladies
wristwatch! MUCH smaller than a small staple, in fact the bore's
hardly bigger than the staple diameter :-)
Anyway, Araldite doesn't stick to waxy plastic like these gears :-(
> I'd be tempted to take a few 10ths of a mm off the inside of the hole
> for the shaft that the gear fits onto. If they're cracking, the shaft
is
> probably too big for the hole.
Enlarging the hole by 0.1mm would make it spin on the shaft :-)
--
Pete Peter Turnbull
Network Manager
University of York
On May 1, 10:14, steve wrote:
> there is tons of stuff on the net, try
>
> http://dcoward.best.vwh.net/analog/
>
> for good introductions, all analog computer are
> basically the same, the biggest difference is how many
> op amps they have, and that limits what you can do.
While that's true for most modern *electronic* analog(ue) computers,
it's not a good generalisation. What about things like Vannevar Bush's
differential analysers, gun directors, Norden bombsights, various
electro-pneumatic or hydraulic computers, or the G-star analog
"computer" used by CalTech at Mt Palomar?
I seem to be in pedant mode today (as Ethan's discovered, possibly) and
I couldn't resist pointing out some alternatives :-)
--
Pete Peter Turnbull
Network Manager
University of York
>From: "Ethan Dicks" <erd_6502(a)yahoo.com>
>
>--- "Peter C. Wallace" <pcw(a)mesanet.com> wrote:
>> Actually all analog computers are _not_ the same.
>>
>> For example: Resistive Sheet computers are very different....
>
>I have an idea of how an analog (electronic) computer would work
>(compared to a mechanical analog computer - that's voodoo with cams)...
>
>How does a resistive sheet computer work?
>
>In the same vein (pun intended)... how would fluidic computers
>stack up? Digital? Analog? Mixed?
>
>-ethan
>The New Yahoo! Search - Faster. Easier. Bingo.
>http://search.yahoo.com
>
Hi
Another type of analog computers include mechanical ones.
During WW2, they used really complicated mechanical fire
control computer. One would input range, bearing, projectile
and charge. It would also take into account ship roll, speed
and coriolis effect for that target.
Gear ratios would make coefficient multipliers. They had variable
speed transmissions to make multipliers. Differentials made adders
and subtracters.
Dwight
Digital VT420 (+ keyboard) for sale
For pick-up in San Francisco, California, USA, only.
12 inch amber monitor, tested, no burn-in, a little dusty.
Setup screen says: VT420 AV 1.4, Copyright 1989 DEC.
If interested please make an offer.
--
tim lindner
tlindner(a)ix.netcom.com
>From: "The Design Fort DTP" <design.fort(a)ns.sympatico.ca>
>
>I would be interested to learn more about the Heathkit EC-1 analog computer.
>So far I only found pictures and specifications on the net. Is there a
>website that actually explained how this machine worked and/or what it
>could/can do.
>Even more are there informations about "programs" that this machine could
>run?
>
>I have to admit that the "analog" times of the computer age was a bit before
>my time, but I really would love to learn more about it.
>
>Herbert
>
Hi
The Heath kit has 9 op-amps that are connected such that
they are all inverting. It is intended to primarily model
things that are linear systems but one can add such things
as diodes to make limiting functions. They do this for one
of the example programs to put a bouncing ball on an oscilloscope
screen. Other nonlinear functions can be added.
Although, one can model things with differentiators, these
are generally not very stable and tend to require more dynamic
range than integrators. Most linear systems can be described
as a differential equation. If one integrates the equation
a number of times, one can remove all the differentials and
be left with a number of integrals and initial constants.
These can be quickly scaled and represented by resistors
and capacitors. This modeling method can solve quite complex
problems. Things like aircraft controls to auto suspension
systems can be modeled this way. I had a friend describe
how it was used to make rail cars that wouldn't oscillate
at the same frequency as the spacing of the track joints,
over normal speed ranges. One can imagine what would happen
to the load and car if it were increasing the oscillation
on each track joint it crossed.
I currently have a EC-1 but a while back, I needed to solve
a control system problem with an oven. There were several
factors that effected the temperature and I needed to make
sure that the system could handle these changes without oscillating
or over shooting. I found an analog modeling program called
TutSim that I used to understand the system. This is just
like using a real analog computer except it used discrete
processing to simulate the analog world. There are potential
problems doing this and one needs to understand the possible
issues.
If you have a spice program, you can build up the equivalent
of a EC-1 in software and see how it works. It wasn't until
the late 80's someplace that digital computers became fast
enough to replace the simpler op-amps for solving these kinds
of problems. In many cases, the analog machines still have
better speed/accuracy tradeoffs.
My biggest complaint with the EC-1 is that they needed more
binding post for the common ( 0 Volts ).
Dwight
Rumor has it that Jason J. Gullickson may have mentioned these words:
>Club100 is the best source I've found, however I run my M100 using a
>cheapo brick from Radio Shack that lets you select from like four or
>five different voltages, so I can't imagine that it needs anything fancy
>(although the battery life is pretty amazing without an adapter).
Just had a couple messages from Rick Hanson this morning... I've known him
(thru email) for nearly a decade, and it's damn hard to find a) a nicer guy
in general, or b) anyone more knowlegable about the inner tickings of
Kyocera-OEMed laptops (including the Tandy Models 100/102/200; NEC 8201a;
Olivetti M10 & friends...)
<MODE=ShamelessPlug>
I also have a mailing list that's available WRT these machines, you can sub
by emailing m100-subscribe(a)list.30below.com -- there's almost 200 people on
the mailing list, so there's quite a following there...
</MODE>
HTH,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger -- sysadmin, Iceberg Computers
zmerch(a)30below.com
What do you do when Life gives you lemons,
and you don't *like* lemonade?????????????
Reply to the original author, not me.
----- Forwarded message from Joacim Melin <listor(a)melin.org> -----
Date: Thu, 1 May 2003 09:18:23 +0200
From: "Joacim Melin" <listor(a)melin.org>
To: <cctalk-admin(a)classiccmp.org>
Subject: Stuff available for pickup in Stockholm, Sweden
Hi all,
time to get rid of some oldies. This is available for collection in
Stockholm, Sweden, for free :
1. Apple II Euro+. Works great but there is no accessories with it. It runs
on 220v at the moment.
2. Deskstation Raptor3. Works great. Comes with :
Full Tower Case
Alpha 21164
UniFlex Motherboard
4 PCI / 3 ISA slots
Dual SCSI II ports
2 serial / 1 parallel ports
1.44 Floppy Drive
Dual SCSI II Interfaces
Please let me know if you are interested in any of this, otherwise it will
go to some landfill instead.
Joacim
----------------------------------------
who > joacim melin
how > joacim(a)melin.org
where > http://z80.org
----------------------------------------
----- End forwarded message -----
--
Jeffrey Sharp
Are you interested in magtape just for the media [has old National
Library
of Medicine stuff? (this would be at least another box)
==================================================
I have been advised that the above tapes are available, probably about
at least a dozen tapes for either the contents or for scratch. The cost
will be for shipping. They are in New York City, but may need to
first be sent to Buffalo.
If they are of interest, please advise and I will try and find out
what arrangements can be made.
I might also be looking to have 3 or 4 magtapes copied to a TK50
(or other suitable media) and might need some help in this regard.
They have RT-11 file labels if that is helpful information, so probably
RT-11 would be needed to make to copies. Eventually, I would like
to copy the contents to a CD.
Sincerely yours,
Jerome Fine
--
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