> On Apr 8, 2016, at 11:59, Seth Morabito wrote:
> One more observation: Two of the three +5V regulators cut out
> when their input voltage exceeds about 11.5V. The input voltage
> comes from a 9.4VAC winding on the primary transformer. Input ripple
> is VERY low, maybe 200mV. So, I suspect those
On Fri, 8 Apr 2016, Cindy Croxton wrote:
No sorry, I do not recall the manufacturer. Most of the boxes had grey
pattern bases with black lids, but a few were brown pattern boxes with dark
brown lids. Not very helpful, I know. I should have taken some pics!
Cindy
Hi Cindy,
Actually somewhat
On 2016-Apr-08, at 11:58 AM, Bill Sudbrink wrote:
> I don't know why I bothering to be coy about it...
>
> My unit here:
>
> http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060005.JPG
> http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060006.JPG
>
> Actually, I'm further along
Thanks everyone who replied. The seller stopped communicating with me so
this time it's a no-go.
But I'm sure there will be a next time :)
/P
On 04/01/2016 11:48 AM, Pontus Pihlgren wrote:
Hi.
I'm considering to ship an empty full height rack from the USA to Sweden. It is
definitely somethin
On 2016-Apr-08, at 11:27 AM, Mouse wrote:
>> I archive all data sheets I run across and I found this information
>> on both TI and Fairchild data sheets for the 78H05, LM340 and LM78XX
>> devices - it is usually under a heading called Application Hints and
>> for some reason Fairchild have removed
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Sean Caron
Sent: Friday, April 08, 2016 4:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: really old test equip
On Fri, 8 Apr 2016, Cindy Croxton wrote:
> When I was at the recycl
On Fri, 8 Apr 2016, Cindy Croxton wrote:
When I was at the recycler last week, I saw a lot of really OLD test
equipment. I started looking through it to see if there were things I could
recognize, but the closest thing I could figure out was a 1940s telephone
equipment tester. All of these were
When I was at the recycler last week, I saw a lot of really OLD test
equipment. I started looking through it to see if there were things I could
recognize, but the closest thing I could figure out was a 1940s telephone
equipment tester. All of these were portable, with lids that closed with
latches
So I just had the incredibly amusing experience of managing to repair an
-11/04 CPU by un-soldering a chip, putting in a socket, and putting _the same
chip_ back in that socket!
Before you go 'WTF?!?!', let me explain what happened.
The CPU wouldn't run, and in poking around, I stumbled on the ca
> > > 1) I have a 12 volt DC supply. 12 volts seems to be
> > >within the VIN range for the 7805s whose data
> > >sheets I've now read. Can I simply apply 12 volts?
> >
> > Yes, but that regulator might get mighty hot! I would
> > not do this for fear of cooking the poor thing.
>
> That
On 04/08/2016 12:11 PM, Tom Gardner wrote:
> Sorry, to a EE they are all epoxies, but:
Gorilla glue is an epoxy? News to me.
Polyurethane is far from stable over the long term and exhibits
hygroscopic properties:
For example, vide:
http://www.ptonline.com/knowledgecenter/Plastics-Drying/Resin-
>
> First, a few quick "whys":
>
> 1) The 7805 is actually a Motorola MC7805CP, date
>code 7308 with gold leads. Very hard to exactly
>replace.
Any reason why it would have to be an exact replacement?
In any case, the behaviour of the 7805 if you apply a
voltage to the output with the
> On Apr 8, 2016, at 3:11 PM, Tom Gardner wrote:
>
> Sorry, to a EE they are all epoxies, but:
>
> "BINDER: A polymer such as polyester-polyurethane used to bind magnetic
> particles together and adhere them to the base film in the manufacturing of
> magnetic media."
> http://www.fujifilmusa.co
>> Entropy: Could the rust on the cookie be de-oxidizing, and turning back int$
> No. If that were true, iron ore would spontaneously turn into iron. Unfort$
Anyone keep their floppies in a hydrogen (or, more generally, reducing)
atmosphere? (Cue xkcd #1426. :-)
/~\ The ASCII
Sorry, to a EE they are all epoxies, but:
"BINDER: A polymer such as polyester-polyurethane used to bind magnetic
particles together and adhere them to the base film in the manufacturing of
magnetic media."
http://www.fujifilmusa.com/shared/bin/Magnetic_Media_Terminology.pdf
"Polyester polyuretha
* On Fri, Apr 08, 2016 at 02:33:25PM -0400, Mouse
wrote:
> > Today, for whatever reason, my Variac was turned down to 110V, and I
> > didn't notice. I turned on the ADM 3a, and... it's fine. [...]
>
> Fascinating!
>
> I have trouble imagining what sort of fault could cause those symptoms.
> I
I don't know why I bothering to be coy about it...
My unit here:
http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060005.JPG
http://wsudbrink.dyndns.org:8080/images/cyclops-latest/P4060006.JPG
Actually, I'm further along than that, but I
don't have more recent photos.
Original unit here
William Donzelli wrote:
> > 1) The 7805 is actually a Motorola MC7805CP, date
> >code 7308 with gold leads. Very hard to exactly
> >replace.
>
> Is that the big flat plastic package with the wide
> flat leads?
Nope, purple ceramic. The heat transfer plate is gold
plated too.
> > 1) I h
Silly question, but then I'm feeling silly today:
Why not just connect the output and input of the 7805 together and power
from the normal +8 line with your +5 supply?
--Chuck
> 1) The 7805 is actually a Motorola MC7805CP, date
>code 7308 with gold leads. Very hard to exactly
>replace.
Is that the big flat plastic package with the wide flat leads? I might
have a few of those around, but I agree, not an easy variant to find.
> 1) I have a 12 volt DC supply. 12
> Today, for whatever reason, my Variac was turned down to 110V, and I
> didn't notice. I turned on the ADM 3a, and... it's fine. [...]
Fascinating!
I have trouble imagining what sort of fault could cause those symptoms.
I would have agreed with whoever (tony, I think) said that if you have
HV t
> I archive all data sheets I run across and I found this information
> on both TI and Fairchild data sheets for the 78H05, LM340 and LM78XX
> devices - it is usually under a heading called Application Hints and
> for some reason Fairchild have removed these Hints from the sheets
> you quote.
> In
First, a few quick "whys":
1) The 7805 is actually a Motorola MC7805CP, date
code 7308 with gold leads. Very hard to exactly
replace.
2) As per the design of the unit, the 7805 is soldered
to the foil side of a single sided, copper clad
circuit board with no through hole plating. Li
Keep in mind that "not powered" and "open" are very different things.
What do the data sheets say?
I will admit that this is all careening towards the academic at this point...
--
Will
On Fri, Apr 8, 2016 at 1:31 PM, John Robertson wrote:
> On 04/08/2016 8:54 AM, wulfman wrote:
>>
>> https://ww
On 04/08/2016 8:54 AM, wulfman wrote:
https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf
http://www.ti.com/lit/ds/symlink/lm78l05.pdf ( page 8 gives you the
internals for a low power version )
Nothing in the data sheet saying you cant apply voltage to the output.
As per the low power versi
OK, I made a very interesting discovery today.
When I'm working on a project on my workbench, I normally have it
plugged into a Variac. This ADM 3a is no exception. I bring up voltage
slowly on any unknown old electronics, and then let it sit at our
normal wall voltage - which currently reads 121V
> If one were to use a dumb CRT terminal from the early '70s regularly in
> this day and age, would it be more prone to hardware failure than if it
> were kept in storage or just kept to look at but powered off?
If you never turn it on, how will you know if the hardware has failed?
More seriiousl
If one were to use a dumb CRT terminal from the early '70s regularly in
this day and age, would it be more prone to hardware failure than if it
were kept in storage or just kept to look at but powered off?
--
Eric Christopherson
https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf
http://www.ti.com/lit/ds/symlink/lm78l05.pdf ( page 8 gives you the
internals for a low power version )
Nothing in the data sheet saying you cant apply voltage to the output.
As per the low power version circuit diagram i cant see how you ca
That's pretty nearly what it says. I'd tweak it as follows.
paul
> On Apr 8, 2016, at 8:42 AM, R SMALLWOOD wrote:
>
>
>> > historische Computer und Rechentechnik>
> The Vintage Computing - Berlin (VCFB) is an event for collectors of old
> computers and calculators.
...an exhibition
>
> This particular 3a has no horizontal scan. None at all. I just get a
> vertical line down the center of the screen. First thing I checked was
> the horizontal deflector on the yoke, which seems secure.
I am going to assume this is a conventional design, I would be very
surprised if not. In wh
On Fri, Apr 08, 2016 at 05:33:43AM -0700, Charles Anthony wrote:
>
> http://www.chdickman.com/pdp8/spacewar/ built his own VC8/I for his PDP-8
> and runs the PDP-8 version of space war on it. He lists the IOT
> instructions for the VC8/I; they are similar to the 338.
Ohh, that looks very doable,
Yo,
When I lived in Florida, I would see Joe several times a year. Since I
moved 10 years ago, we have lost contact.
His wife Sherry, daughter Amy, and Son Adam, do have facebook profiles.
Just do a search for "Rigdon Oviedo" (Florida) and you can find some
links to those family members but
The Vintage Computing - Berlin (VCFB) is an event for collectors of old
computers and calculators.
From : stuebera...@yahoo.de
Date : 06/04/2016 - 23:56 (GMTDT)
To : cctalk@classiccmp.org
Subject : VCF Europe, April 30th - May 1st, Munich + registration for VCF Berlin
Hi list,
the 17th editio
On Thu, Apr 7, 2016 at 9:35 PM, Pontus Pihlgren wrote:
> On Thu, Apr 07, 2016 at 04:08:42PM -0700, Charles Anthony wrote:
> >
> > I have some code that does an X-11 emulation of the Atari Tempest vector
> > graphics display; I'm thinking of wedging it into the simh PDP8 code to
> > emulate the 33
>
> I've been on a tear trying to resurrect old projects here, and next on
> the list is an ADM 3a.
>
> This particular 3a has no horizontal scan. None at all. I just get a
> vertical line down the center of the screen. First thing I checked was
> the horizontal deflector on the yoke, which seems s
On 04/07/2016 4:41 PM, William Donzelli wrote:
Does this warning assume that there is something on Vin, and not open?
With a quick look at the internal schematic of an old-school 7805, it
seems like what Bill suggests (leaving Vin open) will not actually do
much.
--
Will
This warning is for some
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