>From: "Eric Smith" <eric at brouhaha.com>
>
>I wrote:
>> You turn on a particular tube by dropping the X line to 0V and raising
>> the Y line to +105V. The selected tube sees 105V, while the other tubes
>> in the same row and column see 97.5V.
>
>Tom wrote:
>> I think your idea is generally right, but this detail seems wrong:
>> when X goes from +7.5V to 0V, the entire line will see 105V,
>> striking the entire line.
>
>Nope.
>
> 7.5V 0V
>
> X0 X1
> | |
> | |
> 97.5V Y0 --------90V-----------97.5V
> | |
> | |
>105.0V Y1 --------97.5V----------105V
>
>
>Locations (0,0), (1,0), and (1,0) are all still below the strike
>voltage.
>
Hi
When building neon logic, it might be better to consider
using capacitive coupling to connect up your logic.
Otherwise you may find that you'll have a significant
level shifting problem.
Just a thought
Dwight
>From: "Jim Leonard" <trixter at oldskool.org>
---snip---
> For years I've used RAR (WinRAR for windows, RAR and RAR32 for
---snip---
Hi
It seems that may of you are missing the point. The archives
are intended to be useable in say 500 years ( moved to
future media ). Any proprietary application like WinRAR
is useless for this purpose.
I use ZIP files all the time but I would not use any of
this stuff for the purpose of archiving. I surely wouldn't
even consider a window application for archiving.
Even things like error correction need to have their
descriptions in the archive file. Do you expect to package
a X86 simulator and WinRAR into a HTML like format with
each of these compressed files? Back to reality folks!
Dwight
I still
have one of the disks, or I should say set of three, down in the
garage and have been thinking about making a clock out of it.
--
What sort of system did it come from?
I'd hate to see some obscure operating system wiped out
to make a clock.
>from
http://www.computerhistory.org/events/lectures/johnniac_09151998/johnniac_x…
Well, that bell rang frequently. Finally, we had to convince Harriet -- by the
way, this lady worked graveyard shift, midnight to eight in the morning -- to
stay over a little extra, and we would meet with her, and find out what was
going on. We asked Harriet to please go through, in gory detail, exactly what
had happened when the payroll failed. By the way, she couldn?t give me the data,
or anybody else, because Harriet Pierson, besides top management, was the only
[person] allowed to look at payroll data, so -- it was worse than top secret. It
was compartmented like you don?t want to know. Anyway, Harriet stayed over, and
came in, and went through this exercise, and for the exercise she had created
dummy data, just in case we might look at it.
Well, nothing failed, and she couldn?t believe it. So we said, "Tell us exactly
what you did." So we backed up, and she went through the whole thing, and I
said, "Just go back out into the machine room like you normally would, after you
loaded the machine." And she did. The first thing she did is, she walked by the
door, is turn the lights off. But the drapes were open, and there was lots of
light in the room, and so it didn?t have any effect as far as we could tell.
But, when we sat down and thought about all this, we said, "Gee, maybe you?d
better simulate the whole situation." So we closed the drapes, and ran the
payroll program. And sure enough, after about 15 or 20 cards, we got an echo
check error. The damn machine was afraid of the dark. Open the drapes
[laughter], turn the lights on, and the machine ran fine! [Laughter] Makes no
sense. Until Dick Stahl, one of the technicians on the machine, remembered that
the neons were an active part of the circuit, and apparently by running a little
test he determined that without any sunlight coming through in the windows, or
fluorescent light from the overheads, which provided just enough ionization to
keep them active, they deionized to the point where they would no longer
conduct. [Laughter] Now, the question was, how do we fix this? There were
something like two hundred and some odd -- how many neons were there? Well over
200. And nobody wanted to get in there and unsolder and resolder 200 -- the
machine would have been down for a week at that point.
Then somebody had a brilliant idea. Down here, where the air ducts for the
return air from the air conditioner were, they put a bank of fluorescent lights
on each side of the machine. If the filaments were on, they were on, the machine
never had to run in the dark again. It never did. [Laughter] It never was afraid
of the dark again.
>> called SBS (silicon bilateral switch) commonly used to drive
>> Triacs.
> Is this what is also called a Diac (at least in the UK)?
Yes.
Lee.
.
___________________________________________________________
Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com
>
>Subject: Re: Neon bulb logic elements link?
> From: Scott Stevens <chenmel at earthlink.net>
> Date: Wed, 25 May 2005 18:54:11 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Tue, 24 May 2005 22:30:34 +0100 (BST)
>Pete Turnbull <pete at dunnington.u-net.com> wrote:
>
>> On May 24 2005, 17:11, James Fogg wrote:
>>
>> > I seem to recall that neon's behave as diodes. I might be wrong.
>>
>> No, neons happily pass AC. You must be thinking of something else.
>>
>
>Neons act like 'zener diodes' in a sense, perhaps that is where he got
>the notion. Neon lamps fire at a constant voltage and can be used as
>relatively stable voltage references, similar to a zener diode. But
>other than 'voltage reference' use they are completely unlike diodes.
Yes, they are bilateral. There is ssilicon device to mimic the neon
called SBS (silicon bilateral switch) commonly used to drive Triacs.
Allison
>
>Subject: Re: neon tube memories
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Date: Thu, 26 May 2005 00:38:52 +0100 (BST)
> To: cctalk at classiccmp.org
>
>> Unless someone has som ehard data on them being used "digitally"
>> I'd assume the HP counter use was simply as generic, non-switching
>> circuit elements.
>
>The HP5245 counter certainly used neons as memory elements -- I have the
>instrument and the service manual which has a section on the operation of
>the counter module.
>
>Each counter module contains 8 transistors wired as 4 bistables. Diode
>steering is added to make it count either in 1242 BCD code or 1248 (the
>latter being one of the options available for the instrument).
>
>The collectors of the transistors go to the neons via resistor (and
>diode?) networks. By varying the voltage on one of the lines you can
>transfer the state of the counter to the 8 neons and latch it there.
>
>The neons are mounted in a plastic block with a thick-film circuit on
>top. The thich film elements are CdS photoresistors arranged in a decoder
>tree which directly drives a nizie tube.
>
>Quite a hack to get a counter, latch and display driver in just 8
>transistors!
Only takes 4bits to count to 10. Though it could be a switch tail
ring counter.
>> A write-only neon memory would still make a nice addressable
>> display!
>
>Somewhere I have a neon display which seems to be a dot-matix unit (7 dots
>high by perhaps 100 long) with transfer electrodes like a Dekatron tube.
>You apply 7 'bits' to the right hand column, then toggle the transfer
>electrodes appropriately and all the dots move left one column. Repeat to
>built up the pattern you want in the display.
>
>-tony
Boroughs Panaplex, I have a 32char version that I power up and it works.
I've designed using the 40 char version pretty cool. Even got to visit
the facility in NJ back in '73 where they were made along with the other
gas tubes (nixe and the like.).
Allison
Hi,
I have a Data General Nova 4 8394k
I t has no console wiring. I see the pins on the back plane mark console
but don't know much more that. The manual I have, does not really cover
this and the Baud Jumpers don't match up with the CPU board I have.
The CPU board has a bunch of numbers so here they are. All on the Front
edge.
D 0782 P A 005 12066 R04 A005 13542 R 05 T 005 12785 R0
ECO N0 9889 - 10855 - 10388 10595 10758 10199
11013 on a different sticker 1788#4151 on The Board
Is there any site that covers these. ???
- Thanks, Jerry
