On 7/23/2015 12:06 AM, William Donzelli wrote:
As Eric, I'm a member of the PDP-1 Restoration Team. The PDP-1 restoration was
completed in 2005 - and annually we check the power supplies for voltage,
ripple, etc. Not one of the re-formed capacitors have failed in the ten years
since the comple
After having repaired six of these DEC PC05 papertape reader/puncher for
PDP-11, I hacked together a few web pages about my work.
It's not too impressive at the moment, but the info about model variants
and the failure list may be of interest.
See http://retrocmp.com/stories/dec-pc05-papertape
> As Eric, I'm a member of the PDP-1 Restoration Team. The PDP-1 restoration
> was completed in 2005 - and annually we check the power supplies for voltage,
> ripple, etc. Not one of the re-formed capacitors have failed in the ten years
> since the completion of the restoration.
Did the team ev
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 (I
On Tue, 21 Jul 2015, Lyle Bickley wrote:
On Mon, 20 Jul 2015 23:14:36 -0600 Eric Smith wrote:
On Mon, Jul 20, 2015 at 4:46 PM, Rich Alderson
wrote:
industry white papers with tables of decay rates for the aluminum
electrolytics that indicate that, *no matter what*, they lose
capacitance ov
On Wed, Jul 22, 2015 at 9:33 AM, Tothwolf 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 DEC Type 728 power sup
Anyone have a datasheet for the NCR83C11? I believe it is a SCSI transceiver.
Is it an image available?
On Wed, Jul 22, 2015 at 8:32 AM, emanuel stiebler wrote:
> Was a wonderful idea, but the performance of the 432 wasn't nearly what was
> promised.
I'm updating my dictionary to quote that as an example under the
definition of "understatement".
See "Performance Effects of Architectural Complexity
On Wed, Jul 22, 2015 at 8:02 AM, dwight wrote:
> I recall trading a board with one of the 432 family parts with you
> years ago for a disk drive unit.
Thanks again! I've lost track of which 432-related hardware I got
from whom, but I remember that some of it came from you.
> I recall that every
On Wed, Jul 22, 2015 at 12:48 AM, Nigel Williams
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 the SiliconOS
> provided q
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 (i.
> On Jul 22, 2015, at 12:04 PM, Nigel Williams
> wrote:
>
>
>> On 23 Jul 2015, at 12:02 am, dwight 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 open source VHDL simulator, is implemente
> On 23 Jul 2015, at 12:02 am, dwight wrote:
> I'm curious, does anyone program in Ada?
http://www.seas.gwu.edu/~mfeldman/ada-project-summary.html
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 07/22/2015 04:39 AM, tony duell 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.
Why not change all other bulbs on the car at the same time
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
peopl
> From: tony duell
> it's quite possible they started off at the top end of that range, have
> deteriorated over the years, and are still within spec. Of course
> nobody can prove that (unless there are records of the values meaured
> 50 years ago)
Well, I don't know about 50
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
> 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 expensive an
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 was
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 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 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 capaci
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
> From: Guy Sotomayor
> I haven't looked, but I think the Unibus and QBus are comparable in
> terms of pin count.
Well... the QBUS does have those shared address/data lines, so its 'raw'
count (i.e. number of wired-or broadcast bus lines) is somewhat lower (-16
data pins, but +4 addre
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
> > 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: 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
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 fact
> 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 t
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
From: "tony duell"
To: "General Discussion: On-Topic and Off-Topic Posts"
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 all. Like replacing both headlight
> > 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 wr
>
> 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
> > 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 test
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