On Wed, 22 Jul 2015, tony duell wrote:
On Wed, 22 Jul 2015, Noel Chiappa wrote:
I am way out of my knowledge range in this discussion, but here's
something I wanted to ask about: how do you reconcile this observation
(assertion?) with the observations from several people (e.g. the PDP-1
On 7/22/15 7:12 AM, Noel Chiappa wrote:
So, I noticed that on some QBUS cards DEC used a quad transceiver with
tri-state output (on the card side), the AM2908PC. It has separate tri-state
drive enable, and bus drive enable, pins. The FPGA we were looking at
supports bi-directional pins
On Wed, 22 Jul 2015, tony duell wrote:
I think he did answer it. If the unit is operating correctly then the
capacitors must be sufficiently good at that time for that unit.
Now, whether they will go on working is something that is very hard to
tell. But that applies to every other component
Date: Mon, 20 Jul 2015 14:11:46 +
From: tony duell a...@p850ug1.demon.co.uk
Subject: RE: PDP 11 gear finally moved
Replace - yes, *especially* if you don't have a big budget. Aluminum
electrolytic capacitors are CHEAP and easy to obtain. Replacement
semiconductors by comparison are
On Jul 22, 2015, at 12:04 PM, Nigel Williams
n...@retrocomputingtasmania.com wrote:
On 23 Jul 2015, at 12:02 am, dwight dkel...@hotmail.com wrote:
I'm curious, does anyone program in Ada?
http://www.seas.gwu.edu/~mfeldman/ada-project-summary.html
Also, to pick one example, GHDL, the
On 23 Jul 2015, at 12:02 am, dwight dkel...@hotmail.com wrote:
I'm curious, does anyone program in Ada?
http://www.seas.gwu.edu/~mfeldman/ada-project-summary.html
I know a friend who worked on a contract for a project related to
aircraft info. They had all the code done in Ada for their project.
The intent was to allow access to the Norad tracking data at a time when
such as Flightaware and the like were just coming into being as well.
The product
Tail and signaling lights put much more stress on the filament. The
headlights are burned steady in practice and will burn out when they
burn out.
I never replace both, and seldom see any correlation. I just put the
spare in the trunk with the kit to get at the lights when they do fail.
I
On Wed, 22 Jul 2015, tony duell wrote:
Given that a typical aluminum electrolytic capacitor costs anywhere
from $0.12-$0.15 (4mm or 5mm diameter radials) to about $1.00 (12mm or
16mm diameter radial), it also doesn't make much sense to desolder a 20
year old part, spend at a minimum 5 or more
On Wed, Jul 22, 2015 at 12:48 AM, Nigel Williams
n...@retrocomputingtasmania.com wrote:
The 43201 has 4K words of 16 bits of vertical microcode ROM, however
Do you know if this was where the so-called “SiliconOS” was stored? was it
simply mixed in with the regular instruction set? For others
I changed the subject line since unless you recognise 43201 others might not
make the connection :-)
On 22 Jul 2015, at 4:18 pm, Eric Smith space...@gmail.com wrote:
now, I have just wired up the 43201 on a breadboard in microcode ROM
dump mode, and captured the ROM contents using a logic
that are running perfectly just in case...
How do you -know- they are running perfectly? Just because a widget
itself is functioning, you have no way of knowing if that capacitor is
working 100% properly /unless/ you actually remove it from circuit and run
a full battery of tests on it.
I might think twice about doing a board that was fragile with age, but
otherwise, change 'em all. Like replacing both headlight bulbs if one
goes out--it's just a matter of time before the other one goes.
Do you seriously replace both headlight bulbs when one fails? I know of
nobody who
They reliably do what they're supposed to do.
You didn't answer the question. How do you know those aluminum
electrolytic capacitors are functioning just as good as they did when they
were new? Unless you've tested them out of circuit, you simply cannot make
That, actually, is the wrong
From: Tothwolf
How do you know those aluminum electrolytic capacitors are functioning
just as good as they did when they were new? Unless you've tested them
out of circuit ...
... aluminum electrolytic capacitors by their very electrochemical
nature degrade as they
really good caps are better than specs and thus deteriorate into
specs over time, but all fade eventually. Some may have connectors
that die before the cap inside. Rarely does a cap actually measure
the same exactly as what is printed on the label. The ESR value vs.
the capacity is the factor,
From: Tothwolf
How do you know those aluminum electrolytic capacitors are functioning
just as good as they did when they were new? Unless you've tested them
out of circuit ...
... aluminum electrolytic capacitors by their very electrochemical
nature degrade as
Do you seriously replace both headlight bulbs when one fails? I know of
nobody who does that. Generally you carry a spare bulb kit and a screwdriver
and if a bulb fails, pull over and change it.
and - like the capacitor replacement question this is an it depends.
For some cars -
From: tony duell a...@p850ug1.demon.co.uk
To: General Discussion: On-Topic and Off-Topic Posts cctalk@classiccmp.org
Sent: Wednesday, 22 July, 2015 12:39:42 PM
Subject: RE: PDP 11 gear finally moved
I might think twice about doing a board that was fragile with age, but
otherwise, change 'em
Anyone have a datasheet for the NCR83C11? I believe it is a SCSI transceiver.
On Wed, Jul 22, 2015 at 9:33 AM, Tothwolf tothw...@concentric.net wrote:
The only
thing we could know today is if the capacitor passes industry standard tests
and if the power supply those capacitors are a part of functions correctly
when fully loaded.
We built a dummy load for testing the
On 07/22/2015 10:09 PM, Tothwolf wrote:
One example I can give are some Pentium P55C architecture (Socket 7)
systems which I've been running with minimal downtime for ~15 years. The
original power supplies with their original (and relatively low quality)
capacitors lasted about 15 to 17 years
On Wed, 22 Jul 2015, tony duell wrote:
On Wed, 22 Jul 2015, ANDY HOLT wrote:
Do you seriously replace both headlight bulbs when one fails? I know of
nobody who does that. Generally you carry a spare bulb kit and a screwdriver
and if a bulb fails, pull over and change it.
and - like the
On 7/22/15 7:43 AM, Tothwolf wrote:
I can't say I've previously heard of that being done with automotive bulbs
Then why are tail light bulbs sold in pairs?
I just had one go, and replaced both sides.
On 2015-07-22 08:02, dwight wrote:
I recall that everyone was thinking the military would switch to
ADA and the 432 was groomed for that.
It was believed that more correct software could be created that
way. At least the generals bought it.
Was a wonderful idea, but the performance of the 432
Hi Eric
It sounds like your making progress on your 432 studies.
I recall trading a board with one of the 432 family parts with you
years ago for a disk drive unit.
It sounds like you've made progress since then.
I recall that everyone was thinking the military would switch to
ADA and the 432 was
This thread has gone on for a while and I think we all get the points
here, but one other consideration - how will removing and replacing a
component damage the board? Damage the board and it's game over. One
should always take the overall board's ability to handle replacement.
With the board in
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