22 Apr
1999
22 Apr
'99
3:30 a.m.
Mike wrote:
> Perhaps a
> smaller array, but with LARGE cores where the magnetic state could have
> some visual indicators.
How would that work? Would you have an LED for each
bit or something?
Get a little bit away from magnetic storage, and you can use neon
lamps as storage elements which are self-illuminating :-).
Neon lamps - when powered by DC - have a nice memory property: They
take about 90VDC to light up, but after they light up they'll stay on
until the voltage drops below 60VDC or so. Only problems are:
1. The thresholds can vary greatly from unit to unit.
2. The thresholds will vary depending on ambient light, as well.
Property 2 above can be used to build oscillators out of pairs
of neons, as a matter of fact...
Tim.
22 Apr
22 Apr
3:58 a.m.
take about 90VDC to light up, but after they light up
they'll stay on
until the voltage drops below 60VDC or so. Only problems are:
1. The thresholds can vary greatly from unit to unit.
2. The thresholds will vary depending on ambient light, as well.
Use pulse coupleing so each runs at it's range. Also I do have a basic
design for a TTT machine using neons and 2d21 thyratrons.
I feel personally that would be good for demonstrating some for the other
forms of logic used.
Then again someone would want that interfaced to PCI too.
Allison
27 Apr
27 Apr
2:23 a.m.
At 08:58 22/04/99 -0400, allisonp(a)world.std.com wrote:
Use pulse coupleing so each runs at it's range.
Also I do have a basic
design for a TTT machine using neons and 2d21 thyratrons.
I feel personally that would be good for demonstrating some for the other
forms of logic used.
Then again someone would want that interfaced to PCI too.
But it would give your PC flashing lights and would probably keep the
office nice and toasty warm during the winter. "I love the sound of neons
in the morning"
Huw Davies | e-mail: Huw.Davies(a)latrobe.edu.au
Information Technology Services | Phone: +61 3 9479 1550 Fax: +61 3 9479
1999
La Trobe University | "If God had wanted soccer played in the
Melbourne Australia 3083 | air, the sky would be painted green"
22 Apr
22 Apr
3:48 p.m.
On Thu, 22 Apr 1999 CLASSICCMP(a)trailing-edge.com wrote:
Neon lamps - when powered by DC - have a nice memory
property: They
take about 90VDC to light up, but after they light up they'll stay on
until the voltage drops below 60VDC or so. Only problems are:
1. The thresholds can vary greatly from unit to unit.
2. The thresholds will vary depending on ambient light, as well.
Property 2 above can be used to build oscillators out of pairs
of neons, as a matter of fact...
There was a funny story related to that issue (#2) at one of the Computer
Museum History Center's computer history lectures a few months ago. I
hope my attribution is correct, but I seem to remember it was the Johnniac
computer that used neon memory. One day it started malfunctioning. To
make a long story short, the cleaning woman used to come into the computer
room where the Johnniac was, vacuum about, then turn off the lights when
she was done before she left the room. The computer would start
malfunctioning once the lights went out. It took the operators and
engineers a while to figure it all out :)
Sellam Alternate e-mail: dastar(a)siconic.com
------------------------------------------------------------------------------
Don't rub the lamp if you don't want the genie to come out.
Coming this October 2-3: Vintage Computer Festival 3.0!
See http://www.vintage.org/vcf for details!
[Last web site update: 04/03/99]
5 May
5 May
5:48 a.m.
New subject: OT: neon lamps from previous post
Hello -
Does you have a reference on how to build an oscillator or counter out
of neon lamps?
john
Mike wrote:
--
***********************************************************************
* John Ott * Email: jott(a)saturn.ee.nd.edu *
* Dept. Electrical Engineering * *
* 275 Fitzpatrick Hall * *
* University of Notre Dame * Phone: (219) 631-7752 *
* Notre Dame, IN 46556 USA * *
***********************************************************************
> Perhaps a
> smaller array, but with LARGE cores where the magnetic state could have
> some visual indicators.
How would that work? Would you have an LED for
each bit or something?
Get a little bit away from magnetic storage, and you can use neon
lamps as storage elements which are self-illuminating :-).
Neon lamps - when powered by DC - have a nice memory property: They
take about 90VDC to light up, but after they light up they'll stay on
until the voltage drops below 60VDC or so. Only problems are:
1. The thresholds can vary greatly from unit to unit.
2. The thresholds will vary depending on ambient light, as well.
Property 2 above can be used to build oscillators out of pairs
of neons, as a matter of fact...
Tim.
2:11 p.m.
New subject: OT: neon lamps from previous post
John Ott <jott(a)mastif.ee.nd.edu> wrote:
< 470K
<
|
+------+
| |
(:)NE2 _
| - .1 uF 100V
| |
+------+
|
GND
It seems like there was an article, way back, in Scientific American
that showed flop-flops and gating logic. I don't recall the exact
values needed but they were based on the condition that when using
two neons and a shared current source, if both where lit, the voltage
drop across the common limiting resistor would be too much to keep
both lamps lit at the same time. Only one lamp by it self could stay
on. Other resistors were used to isolate the two and provide input
and output through coupling capacitors.
Dwight
Hello -
Does you have a reference on how to build an oscillator or counter out
of neon lamps?
john
Hi
Simple oscillator using NE-2:
90 VDC
|
3:33 p.m.
New subject: OT: neon lamps from previous post
At 04:11 PM 5/5/99 -0700, Dwight wrote:
John Ott <jott(a)mastif.ee.nd.edu> wrote:
> Hello -
> Does you have a reference on how to build an oscillator or counter out
> of neon lamps?
>
> john
Simple oscillator using NE-2:
Here's another "flip-flop" which can be expanded upon with steering diodes,
etc.:
90 VDC
+--------+
-Dave
>
< 470K <
>
< <
| |
+---||---+ 0.1uF
| |
(:)NE2 (:)
| |
| |
+--------+
|
GND
6 May
6 May
9:24 p.m.
New subject: DECmate III restoration
During a (somewhat enforced) break from work, I decided to start work on
restoring some of my old collection of computers. I decided to start on my
DECmate III (I've never played with one before).
All seems OK, on power up the screen comes on, all four lights on the LK201
come on and the RX50s start and accesses the floppy I found in the drive
(notated DM/WPS System Diskette V2.1.2 Backup Copy - Working). All I now
get is 16 sitting in the middle of the screen and a large cursor in the top
left corner of the screen. I'm guessing either the floppy is bad or I need
another/more.
I've organized a colleague to bring home a 5.25" floppy drive which will
get installed in my NT/Alpha box. I guess I need pointers to what I need to
do to get the DECmate running WPS and what I need to install OS/278 which I
what I really want to do with this box.
Pointers to a simple terminal emulation program would be useful - the
DECmate will spend at least some of it's life as the console to my home
network gateway/firewall....
Huw Davies | e-mail: Huw.Davies(a)latrobe.edu.au
Information Technology Services | Phone: +61 3 9479 1550 Fax: +61 3 9479
1999
La Trobe University | "If God had wanted soccer played in the
Melbourne Australia 3083 | air, the sky would be painted green"
9185
days inactive
9200
days old
7 comments
7 participants
participants (7)
-
allisonp＠world.std.com -
CLASSICCMP＠trailing-edge.com -
dastar＠ncal.verio.com -
ddameron＠earthlink.net -
elvey＠hal.com -
H.Davies＠latrobe.edu.au -
jott＠mastif.ee.nd.edu