date:20150930

Hey guys,

I'm fairly certain this is a serial board - mostly because the PO told me
so, and when I received it, it had a 25-pin male connector on a three-wire
cable carelessly soldered to the pads behind one of the cable headers on
the top edge. But the cable was removed as a matter of course when I was
prepping the machine for a rebuild. I mistakenly assumed that the docs
would be trivial to locate - so no need to record the original wiring
connections.

.

On Thu, Oct 1, 2015 at 12:26 AM, tony duell  wrote:

>
> > I couldn't spot how they did level shifting to RS232 levels.  The SI
> > signal appears to go to a 7400 next to one of the Uarts.
>
> There are a couple of 8 pin ICs near the 10 pin headers, they look to
> be 1458 dual op-amps (I can't exactly make out the numbers...).
>
> Op-amps were often used as RS232 drivers. Give them +/-12V supplies,
> feed a TTL signal into one of the inputs, connect the other input to a
> voltage between the TTL levels (potential divider from the 5V line) and
> apply no negative feedback. The Op-amp output will swing between the
> supply rails.
>
> -tony
>

RE: One more try - Can you ID this S-100 Serial board?

2015-09-30 Thread tony duell


> I couldn't spot how they did level shifting to RS232 levels.  The SI
> signal appears to go to a 7400 next to one of the Uarts.

There are a couple of 8 pin ICs near the 10 pin headers, they look to
be 1458 dual op-amps (I can't exactly make out the numbers...). 

Op-amps were often used as RS232 drivers. Give them +/-12V supplies,
feed a TTL signal into one of the inputs, connect the other input to a
voltage between the TTL levels (potential divider from the 5V line) and
apply no negative feedback. The Op-amp output will swing between the
supply rails.

-tony

Re: One more try - Can you ID this S-100 Serial board?


On Wed, 30 Sep 2015, jwsmobile wrote:

I couldn't spot how they did level shifting to RS232 levels.  The SI 
signal appears to go to a 7400 next to one of the Uarts.


One of the Uarts is one which requires it would seem 12 v as well, but 
it doesn't do the levels for rs232 (AY-3-1015)


I'd need sharper images and possession of the board to peer at it for an 
hour or so to try to figure it out.


Also the edge card space from the dual 50 pin headers seem to be 
suspicious. i don't have an S100 spec to look at handy, but I was going 
to see if there is any decoding going on, or maybe this is just a buffer 
board to go to another system.  There seems to be a lot of LS244 and so 
forth going on on the way to the edge card connectors, which smells more 
like a buffer board than a serial board.  that is is not populated but 
for the two 10 pin connectors is more interesting.


Maybe someone else will figure out more or know more.


The resistor networks connected to those traces are also not populated.

Wonder what the deal is with the missing C2 right next to the crystal 
though? Broken off?

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

Well, it's all the same Linux kernel; for each branch of each distribution,
they pick a kernel train they want to run with and then backport patches as
required for security or device driver support from more modern kernels ...
Nothing to stop you from running X kernel (or Z window manager) on Y
distribution, generally. The primary differentiator is really the packaging
scheme; whether it uses the Debian style (*.deb) or the Red Hat (*.rpm)
style or perhaps something more basic (*.tar.gz) like Slackware.

While there are a few "forks" of BSD, there never was a proliferation of
various "distributions"; that is to say, there is only one, definitive
FreeBSD, one, definitive NetBSD and one, definitive OpenBSD. All are
significantly stripped of crud out of the box compared to Linux.

Ironically, I had to migrate a few of my home servers _to_ Linux _from_
FreeBSD (with some reticence) because FreeBSD dropped support for my Fore
PCA-200E cards and I didn't want to stop running OC-3 MM ATM at home :O

I do still run some FreeBSD systems at home but just as ESXi VMs.

Best,

Sean

On Wed, Sep 30, 2015 at 6:42 PM, Chuck Guzis  wrote:

> On 09/30/2015 02:50 PM, Sean Caron wrote:
>
>> Just the whole idea of so many Linux distributions makes me bang my
>> head against the coffee table. One thing I greatly admire about the
>> *BSD projects has been the strong arm of unification, all
>> contributors are working towards one goal... It just so happened that
>> Linux was the "free UNIX that took off" (just like i386 was the
>> "architecture that won") and we have to live with the repercussions
>> of that in IT ops every day for better or for worse ... But that's
>> just my two cents and no more ... I know this topic can get
>> religious! :O
>>
>
> I find that most of the difference between Linuces lies in the GUI, not in
> the "guts" of the system.  Many, if not, most use a Debian-based kernel
> with other stuff bolted on--and even that's not cast in Sakrete.  I'm
> sitting at a system now running Ubuntu with the XFCE desktop (I can't stand
> Unity).  At the command-line level, there's little that's substantially
> different among Linuces.
>
> Anent BSD, you'll find considerable differences in approaches to OpenBSD
> compared with FreeBSD.  OpenBSD is conservative to the point of being
> almost paranoid, an approach I greatly admire.  OpenBSD management seems to
> despise virtualization in any form, so no Wine for you, much less
> VirtualBox.  Ftp is not officially supported, etc.  Compared to OpenBSD,
> FreeBSD is a painted whore.
>
> It's been a long time since I've updated my systems with NetBSD, so it's
> hard to say much there.
>
> Linux is getting to be (or has gotten to be) the host of the latest shiny
> toy.  They no longer support older chipsets, such as the VIA 8237A
> nothbridge (it was just ripped out without commentary, so you have no hard
> disk access).  The BSDs--and even Windows seem to have kept it.
>
> --Chuck
>

Re: One more try - Can you ID this S-100 Serial board?

2015-09-30 Thread jwsmobile

I couldn't spot how they did level shifting to RS232 levels.  The SI 
signal appears to go to a 7400 next to one of the Uarts.


One of the Uarts is one which requires it would seem 12 v as well, but 
it doesn't do the levels for rs232  (AY-3-1015)


I'd need sharper images and possession of the board to peer at it for an 
hour or so to try to figure it out.


Also the edge card space from the dual 50 pin headers seem to be 
suspicious.  i don't have an S100 spec to look at handy, but I was going 
to see if there is any decoding going on, or maybe this is just a buffer 
board to go to another system.  There seems to be a lot of LS244 and so 
forth going on on the way to the edge card connectors, which smells more 
like a buffer board than a serial board.  that is is not populated but 
for the two 10 pin connectors is more interesting.


Maybe someone else will figure out more or know more.

thanks
Jim


On 9/30/2015 6:22 PM, drlegendre . wrote:

In fact, I did not. Thanks for the tip! ;-)

On Wed, Sep 30, 2015 at 8:18 PM, william degnan 
wrote:


Did you try asking @ retrotechnology.com

Bill Degnan
twitter: billdeg
vintagecomputer.net
On Sep 30, 2015 8:52 PM, "drlegendre ."  wrote:


(Months along, posts to several boards / lists, still no help on this

one..

so I'm giving it another shot. I'd really like to use this board)

Been trying to no avail to find any info on this 'MCT' S-100 serial card.
I'm pretty sure the card works, as it came from a previously-working

system

- but all documents are missing, and without the info, I have no idea how
to put it to use. Photos are here:

https://nerp.net/~legendre/altair/mct_serial_01.jpg
https://nerp.net/~legendre/altair/mct_serial_02.jpg

Other than what I believe is an artwork / batch number on the rear, the
only marking is "Assy 105510" on the front silk screen. My hunch is that
this may have been a fairly generic 'OEM' type card which could have been
re-badged and sold under one or more different names. So perhaps the docs
exist under a name other than MCT?

Any help greatly appreciated - thanks!

-Bill

Re: ESR Meter Recommendations


On Wed, 30 Sep 2015, John Robertson wrote:

On 09/30/2015 5:22 PM, Tothwolf wrote:

I bought a kit from anatekcorp.com last year to replace my Dick Smith 
version that spouted legs and was rather disappointed with how it had 
been kitted up. A lot of the components were very low quality or did 
not fit the board properly, so I substituted my own. Even the 9V 
battery snap was made wrong (bad quality wire and the snap was made 
backwards). Another oddity was the kit included two 18 pin dip sockets 
instead of an 18 pin and a 16 pin (I used some 3M dual wipe sockets 
that I had anyway).


One thing that really bothered me about the 'Blue ESR' variation 
compared to the original Dick Smith version was the lack of banana 
jacks, however I found some shrouded jacks which fit the blue Hammond 
enclosure.


If there is any interest in the changes I made to my meter, I'll see 
about digging up my notes/parts list and the photos I took during 
assembly.


The new kit makers seem to be doing a good job on fitting the kits out 
properly, had a little trouble with the first batch and they quickly 
sent me missing parts. Heck, I remember problems I had with Dick Smith 
kits back in the early 00s - missing circuit boards, wrong parts, etc. 
However DS (and Anatek) ALWAYS made good on shortages.


It wasn't really a case of missing parts, just really poor quality parts 
apparently purchased in bulk based on price and little else (which may 
also be the reason why my kit had two 18 pin sockets in it). Some of the 
parts also looked suspiciously like the really junk stuff you find from 
the far-east eBay resellers. The capacitors they included did not match 
the lead spacing on the board (cheaper off-brand 5mm dia, 2mm ls parts 
instead of low profile 6.3mm dia 2.5mm ls), although I had no trouble at 
all finding the correct low-profile parts from Mouser that the board 
seemed to be designed for (IIRC, Nichicon SA and SR series electrolytics). 
Even the trimmer resistors were the wrong format for the board, which I 
replaced with some high quality Bourns parts that fit perfectly. Heck, 
even the Omron button cap was selected based on price...a tiny square cap 
intended to poke through a round hole? I used a larger round button cap 
from Omron.


Plus Bob Parker is still helping folks with his kit, he has a great 
support site in AU for these kits.


http://members.ozemail.com.au/~bobpar/esrmeter.htm (note the lack of 
twitter or facebook links - "This web page is for grownups"!)


FYI the kit leads have banana sockets on them...so you can quick connect 
the optional probes or use your own.


...yeah. About that...those leads and banana plugs are *terrible*. 
Absolutely junk. [Not to mention if you plug the "banana plugs" they 
include into the test probes they offer, there is no safety shroud at the 
plug to probe connection.] The little short wires they included were 
kinked, sticky, and were /never/ going to work out well. Maybe they would 
be find for a hobbyist who uses the tool every once in awhile, but for 
daily use? No way.


I also wanted to be able to use my Probe Master and Parrot Clip test leads 
with it. The original Dick Smith version had banana jacks, although they 
weren't shrouded and weren't standard 0.75" spacing, however the shrouded 
jacks I added to my Blue ESR meter are standard 0.75" spacing, so I can 
use double-banana plugs with them if I want to.


I took lots of photos and notes with the intent to write up a full 
critical review of it, but I've just been too busy with other projects. My 
personal opinion is the fit and finish of the Blue ESR meter out of the 
box isn't up to par and they charge way too much for the kit to be 
substituting in low quality components.

Re: One more try - Can you ID this S-100 Serial board?

In fact, I did not. Thanks for the tip! ;-)

On Wed, Sep 30, 2015 at 8:18 PM, william degnan 
wrote:

> Did you try asking @ retrotechnology.com
>
> Bill Degnan
> twitter: billdeg
> vintagecomputer.net
> On Sep 30, 2015 8:52 PM, "drlegendre ."  wrote:
>
> > (Months along, posts to several boards / lists, still no help on this
> one..
> > so I'm giving it another shot. I'd really like to use this board)
> >
> > Been trying to no avail to find any info on this 'MCT' S-100 serial card.
> > I'm pretty sure the card works, as it came from a previously-working
> system
> > - but all documents are missing, and without the info, I have no idea how
> > to put it to use. Photos are here:
> >
> > https://nerp.net/~legendre/altair/mct_serial_01.jpg
> > https://nerp.net/~legendre/altair/mct_serial_02.jpg
> >
> > Other than what I believe is an artwork / batch number on the rear, the
> > only marking is "Assy 105510" on the front silk screen. My hunch is that
> > this may have been a fairly generic 'OEM' type card which could have been
> > re-badged and sold under one or more different names. So perhaps the docs
> > exist under a name other than MCT?
> >
> > Any help greatly appreciated - thanks!
> >
> > -Bill
> >
>

Re: One more try - Can you ID this S-100 Serial board?

2015-09-30 Thread william degnan

Did you try asking @ retrotechnology.com

Bill Degnan
twitter: billdeg
vintagecomputer.net
On Sep 30, 2015 8:52 PM, "drlegendre ."  wrote:

> (Months along, posts to several boards / lists, still no help on this one..
> so I'm giving it another shot. I'd really like to use this board)
>
> Been trying to no avail to find any info on this 'MCT' S-100 serial card.
> I'm pretty sure the card works, as it came from a previously-working system
> - but all documents are missing, and without the info, I have no idea how
> to put it to use. Photos are here:
>
> https://nerp.net/~legendre/altair/mct_serial_01.jpg
> https://nerp.net/~legendre/altair/mct_serial_02.jpg
>
> Other than what I believe is an artwork / batch number on the rear, the
> only marking is "Assy 105510" on the front silk screen. My hunch is that
> this may have been a fairly generic 'OEM' type card which could have been
> re-badged and sold under one or more different names. So perhaps the docs
> exist under a name other than MCT?
>
> Any help greatly appreciated - thanks!
>
> -Bill
>

Re: ESR Meter Recommendations


On 09/30/2015 5:22 PM, Tothwolf wrote:

On Wed, 30 Sep 2015, John Robertson wrote:

On 09/29/2015 2:59 PM, Jay West wrote:


This is the one I have used for years.

http://clientes.netvisao.pt/greenpal/evb1.htm

About $88 USD


That is an authorized Bob Parker variation of his original Dick Smith 
ESR meter kit. On this side of the pond they were made by Anatek 
until the owner was killed in an accident, then the series (now 
called the Blue ESR) is made by Alltronics and sold by dealers such 
as I. These all use Bob's licensed code, just different box and PCB 
layouts.


If you want a Blue ESR I sell them on my web site's catalogue 
section, or you can order the EVB from Portugal if you are on the 
east side of the pond.


I've been selling variations (evolution by intelligent design) of 
Bob's ESR meter kit since 1999!


I bought a kit from anatekcorp.com last year to replace my Dick Smith 
version that spouted legs and was rather disappointed with how it had 
been kitted up. A lot of the components were very low quality or did 
not fit the board properly, so I substituted my own. Even the 9V 
battery snap was made wrong (bad quality wire and the snap was made 
backwards). Another oddity was the kit included two 18 pin dip sockets 
instead of an 18 pin and a 16 pin (I used some 3M dual wipe sockets 
that I had anyway).


One thing that really bothered me about the 'Blue ESR' variation 
compared to the original Dick Smith version was the lack of banana 
jacks, however I found some shrouded jacks which fit the blue Hammond 
enclosure.


If there is any interest in the changes I made to my meter, I'll see 
about digging up my notes/parts list and the photos I took during 
assembly.


The new kit makers seem to be doing a good job on fitting the kits out 
properly, had a little trouble with the first batch and they quickly 
sent me missing parts. Heck,  I remember problems I had with Dick Smith 
kits back in the early 00s - missing circuit boards, wrong parts, etc. 
However DS (and Anatek) ALWAYS made good on shortages.


Plus Bob Parker is still helping folks with his kit, he has a great 
support site in AU for these kits.


http://members.ozemail.com.au/~bobpar/esrmeter.htm  (note the lack of 
twitter or facebook links - "This web page is for grownups"!)


FYI the kit leads have banana sockets on them...so you can quick connect 
the optional probes or use your own.


John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

RE: ESR Meter Recommendations

2015-09-30 Thread Marc Verdiell

I have been using the BK Precision 879B:
http://www.testequipmentdepot.com/bk-precision/lcr/879b.htm?ref=gbase&gclid=
CKj82-uIoMgCFRNrfgodYOYOvA
It's at a completely different price point ($250-ish), and much more than an
ESR meter - but it's a bargain for a full R,C,L,Z meter. Very useful to know
not only the ESR, but the actual value of the capacitance (which for big
power supply caps could have diminished significantly over the years). It
can measure components at 100Hz, 1000Hz and 10Khz. You could not justify it
for a single power supply repair, but if you do a lot of old electronics
restoration projects, it is a precious tool to have. I couldn't live without
it now.
You can see it in action in the middle of this video here, in this case
exonerating a capacitor that I sure thought was the cause of my power
problem, but turned out to be perfectly good:
https://www.youtube.com/watch?v=lqD6xVI6qNs

Marc

 ==
From: Ken Seefried 
Subject: ESR Meter Recommendations

I'm going to be working on my 11/730s power supply, so I'm in the
market for an ESR meter.  I've seen some (older) recommendations for
the AnaTek 'Blue' and various 'Dick Smith' derivatives.  However, eBay
is flooded with knockoff Mega328 based ESR/Transistor/SCR/etc. testers
all looking like:

http://www.amazon.com/DROK-Multifunction-Mega328-Transistor-Capacitor/dp/B00
NKY3M1W/ref=sr_1_16?ie=UTF8&qid=1443561246&sr=8-16&keywords=esr+meter
Anyone had any experience with one of these devices?

KJ
=

One more try - Can you ID this S-100 Serial board?

(Months along, posts to several boards / lists, still no help on this one..
so I'm giving it another shot. I'd really like to use this board)

Been trying to no avail to find any info on this 'MCT' S-100 serial card.
I'm pretty sure the card works, as it came from a previously-working system
- but all documents are missing, and without the info, I have no idea how
to put it to use. Photos are here:

https://nerp.net/~legendre/altair/mct_serial_01.jpg
https://nerp.net/~legendre/altair/mct_serial_02.jpg

Other than what I believe is an artwork / batch number on the rear, the
only marking is "Assy 105510" on the front silk screen. My hunch is that
this may have been a fairly generic 'OEM' type card which could have been
re-badged and sold under one or more different names. So perhaps the docs
exist under a name other than MCT?

Any help greatly appreciated - thanks!

-Bill

RE: ESR Meter Recommendations


On Wed, 30 Sep 2015, Jay West wrote:

Question - I could be mistaken, but I think someone mentioned that these 
were not good for testing caps that had a higher operating voltage. Is 
that correct? My understanding was that the testing method used by this 
ESR meter was valid for most all the large electrolytics...?


You can measure the ESR of any capacitor, however for large filter 
capacitors, a leakage tester is likely to be more important.

Re: ESR Meter Recommendations


On Wed, 30 Sep 2015, John Robertson wrote:

On 09/29/2015 2:59 PM, Jay West wrote:


This is the one I have used for years.

http://clientes.netvisao.pt/greenpal/evb1.htm

About $88 USD


That is an authorized Bob Parker variation of his original Dick Smith 
ESR meter kit. On this side of the pond they were made by Anatek until 
the owner was killed in an accident, then the series (now called the 
Blue ESR) is made by Alltronics and sold by dealers such as I. These all 
use Bob's licensed code, just different box and PCB layouts.


If you want a Blue ESR I sell them on my web site's catalogue section, 
or you can order the EVB from Portugal if you are on the east side of 
the pond.


I've been selling variations (evolution by intelligent design) of Bob's 
ESR meter kit since 1999!


I bought a kit from anatekcorp.com last year to replace my Dick Smith 
version that spouted legs and was rather disappointed with how it had been 
kitted up. A lot of the components were very low quality or did not fit 
the board properly, so I substituted my own. Even the 9V battery snap was 
made wrong (bad quality wire and the snap was made backwards). Another 
oddity was the kit included two 18 pin dip sockets instead of an 18 pin 
and a 16 pin (I used some 3M dual wipe sockets that I had anyway).


One thing that really bothered me about the 'Blue ESR' variation compared 
to the original Dick Smith version was the lack of banana jacks, however I 
found some shrouded jacks which fit the blue Hammond enclosure.


If there is any interest in the changes I made to my meter, I'll see about 
digging up my notes/parts list and the photos I took during assembly.

Re: Ping to Tim Shoppa

2015-09-30 Thread Jerome H. Fine

>Jerome H. Fine wrote:

>Eric Christopherson wrote:

On Tue, Sep 29, 2015, Jerome H. Fine wrote:

This post is for Tim Shoppa.

This have seen your replies every so often on classiccmp, so you
don't seem to be totally out of touch.

If you are reading this, Alan Frisbie and I would appreciate
some help.

Allan can be reached at the address to which I sent a copy.

If you CCed someone, that seems to have been stripped by the mailing
list.

I sent an e-mail directly to Tim this morning. I have seen
replies from Tim in the past, so I know he must watch
these posts.

Has anyone located a PDF on the internet for the RT-11
Release Notes from the V05.07 DOC set in October 1998?

On reading my reply again, I probably did not respond very accurately.

I did NOT CC Tim Shoppa when I sent my second e-mail to
classiccmp SINCE, as I did state in my first response that I
had sent my initial request directly to Tim Shoppa at the last
e-mail address that I did have.

As to the real reason why I am clarifying, Tim Shoppa has already
responded and has sent a PDF file of the V05.07 Release Notes
to Al Kossow and myself. Al Kossow may have already placed
the PDF file on the bitsavers archive. However, at the trailing-edge
mirror, the new file is DEFINITELY already there! Since some
individuals might have been following this thread rather than the
thread about PDF for RT-11 V05.07 Release Notes, I am
updating the information here as well.

All of the V05.06 RT-11 DOC set manuals are available at:
<>http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.6_Aug91/

EXCEPT for the V05.06 RT-11 System Release Notes manual,
ALL of the other manuals are IDENTICAL for the V05.07 RT-11
DOC set manuals.

The old and new PDF files, respectively, along with the links are:
AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.6_Aug91/AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf

AA-5286M-TC_RT-11_System_Release_Notes_Aug98.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.7_Aug98/AA-5286L-TC_RT-11_System_Release_Notes_Aug98.pdf

A BIG THANK YOU to Tim Shoppa for making this PDF available.

Jerome Fine

Re: ESR Meter Recommendations

Good primer paper from Sencore (manufacturer of instruments, not
capacitors..) on the nature, causes and effects of ESR:

http://patriotgaming.com/manuals/gaming_monitors/sencore_instruments/LC103/TT104-4416.pdf

On Wed, Sep 30, 2015 at 5:50 PM, drlegendre .  wrote:

> "How are
> folks testing the very large electrolytics in the 25,000, 80,000 or even
> 100,000 uF range that are encountered in the power supplies of some of
> these old machines?"
>
> The method I use is pretty close to what you mention, though I lack an
> electronic load. Here are some thoughts...
>
> For measuring capacity - on these rather large-value caps, it's quite
> acceptable to time their discharge rate through a known, stable resistance
> of some reasonable value based on the marked capacitance. Make several runs
> and average them out. Calculating value is then simple arithmetic - C=T/R.
>
> For leakage, I use a variable voltage-regulated PSU with current-viewing
> resistor in series. At what percent of marked voltage does leakage clear
> the noise? At what voltage does it become significant and at what point
> does it exceed allowable? All electrolytics leak, and the larger value the
> part, the more expected leakage. Check a datasheet, or just use your
> experience and make educated guesses - hint: how much power (as in heat
> rejection) is the cap dissipating at working voltages vs. its marked value
> and physical size?
>
> And as you suggest, watching supply ripple on the scope, with the cap
> under some nominal load, is a tried & true method. It's usually my first
> step, if I think a cap might be in trouble.
>
> (I was certain that I'd have to replace the 30 yr-old 95,000uF part in my
> Altair.. but the dang thing proofed out just fine. Ran it for a day at 10%
> over working voltage, and leakage sat right where it was when I began the
> test. )
>
> On Wed, Sep 30, 2015 at 1:35 PM, Chris Elmquist  wrote:
>
>> On Wednesday (09/30/2015 at 10:54AM -0700), John Robertson wrote:
>> >
>> > As for testing large capacitors, about the highest value that gives
>> useful
>> > readings is around 10,000ufd. Larger than that and the ESR is too close
>> to
>> > zero ohms unless the cap is really bad...
>>
>> And that seems to be the usual situation for most ESR meters.  How are
>> folks testing the very large electrolytics in the 25,000, 80,000 or even
>> 100,000 uF range that are encountered in the power supplies of some of
>> these old machines?
>>
>> One approach I use has been to isolate the supply and then fire it up
>> with an electronic load while looking at voltage sag and ripple on a
>> scope while that load is swept from min to max capability of the supply.
>>
>> There is also the Sencore LC53 "Z Meter" which can test large caps up
>> to 200,000 uF out of circuit but these are typically a $400+ instrument
>> on the used market.
>>
>> http://bama.edebris.com/download/sencore/lc53/LC53%20OPS.pdf
>>
>> Chris
>> --
>> Chris Elmquist NØJCF
>>
>>
>

Re: ESR Meter Recommendations

"How are
folks testing the very large electrolytics in the 25,000, 80,000 or even
100,000 uF range that are encountered in the power supplies of some of
these old machines?"

The method I use is pretty close to what you mention, though I lack an
electronic load. Here are some thoughts...

For measuring capacity - on these rather large-value caps, it's quite
acceptable to time their discharge rate through a known, stable resistance
of some reasonable value based on the marked capacitance. Make several runs
and average them out. Calculating value is then simple arithmetic - C=T/R.

For leakage, I use a variable voltage-regulated PSU with current-viewing
resistor in series. At what percent of marked voltage does leakage clear
the noise? At what voltage does it become significant and at what point
does it exceed allowable? All electrolytics leak, and the larger value the
part, the more expected leakage. Check a datasheet, or just use your
experience and make educated guesses - hint: how much power (as in heat
rejection) is the cap dissipating at working voltages vs. its marked value
and physical size?

And as you suggest, watching supply ripple on the scope, with the cap under
some nominal load, is a tried & true method. It's usually my first step, if
I think a cap might be in trouble.

(I was certain that I'd have to replace the 30 yr-old 95,000uF part in my
Altair.. but the dang thing proofed out just fine. Ran it for a day at 10%
over working voltage, and leakage sat right where it was when I began the
test. )

On Wed, Sep 30, 2015 at 1:35 PM, Chris Elmquist  wrote:

> On Wednesday (09/30/2015 at 10:54AM -0700), John Robertson wrote:
> >
> > As for testing large capacitors, about the highest value that gives
> useful
> > readings is around 10,000ufd. Larger than that and the ESR is too close
> to
> > zero ohms unless the cap is really bad...
>
> And that seems to be the usual situation for most ESR meters.  How are
> folks testing the very large electrolytics in the 25,000, 80,000 or even
> 100,000 uF range that are encountered in the power supplies of some of
> these old machines?
>
> One approach I use has been to isolate the supply and then fire it up
> with an electronic load while looking at voltage sag and ripple on a
> scope while that load is swept from min to max capability of the supply.
>
> There is also the Sencore LC53 "Z Meter" which can test large caps up
> to 200,000 uF out of circuit but these are typically a $400+ instrument
> on the used market.
>
> http://bama.edebris.com/download/sencore/lc53/LC53%20OPS.pdf
>
> Chris
> --
> Chris Elmquist NØJCF
>
>

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Chuck Guzis


On 09/30/2015 02:50 PM, Sean Caron wrote:

Just the whole idea of so many Linux distributions makes me bang my
head against the coffee table. One thing I greatly admire about the
*BSD projects has been the strong arm of unification, all
contributors are working towards one goal... It just so happened that
Linux was the "free UNIX that took off" (just like i386 was the
"architecture that won") and we have to live with the repercussions
of that in IT ops every day for better or for worse ... But that's
just my two cents and no more ... I know this topic can get
religious! :O


I find that most of the difference between Linuces lies in the GUI, not 
in the "guts" of the system.  Many, if not, most use a Debian-based 
kernel with other stuff bolted on--and even that's not cast in Sakrete. 
 I'm sitting at a system now running Ubuntu with the XFCE desktop (I 
can't stand Unity).  At the command-line level, there's little that's 
substantially different among Linuces.


Anent BSD, you'll find considerable differences in approaches to OpenBSD 
compared with FreeBSD.  OpenBSD is conservative to the point of being 
almost paranoid, an approach I greatly admire.  OpenBSD management seems 
to despise virtualization in any form, so no Wine for you, much less 
VirtualBox.  Ftp is not officially supported, etc.  Compared to OpenBSD, 
FreeBSD is a painted whore.


It's been a long time since I've updated my systems with NetBSD, so it's 
hard to say much there.


Linux is getting to be (or has gotten to be) the host of the latest 
shiny toy.  They no longer support older chipsets, such as the VIA 8237A 
nothbridge (it was just ripped out without commentary, so you have no 
hard disk access).  The BSDs--and even Windows seem to have kept it.


--Chuck

Re: PDF for RT-11 V05.07 Release Notes

2015-09-30 Thread Jerome H. Fine

>Jerome H. Fine wrote:

This request is for Al Kossow. However, if anyone else knows
where AA-5286M-TC is located as a PDF on the internet, it
would be appreciated.

I have downloaded the V05.06 PDF from one of the mirrors:
AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.6_Aug91/AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf

THANK YOU very much for making this PDF available.

However, I don't see the V05.07 PDF of the RT-11 Release
Notes anywhere. If there is a copy, could you please provide
the link?

I presumed that if it existed, that PDF file would have been at:

AA-5286M-TC_RT-11_V5.7_Release_Notes_Oct98.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.7_Oct98/AA-5286M-TC_RT-11_V5.7_Release_Notes_Oct98.pdf

but that sub-directory does not exist.

As I have mentioned in a previous post, the RT-11 DOC set
manuals for V05.06 and V05.07 are IDENTICAL except for:
AA-5286L-TC RT-11 Release Notes for V05.06 of RT-11
which was dated August 1991 and
AA-5286M-TC RT-11 Release Notes for V05.07 of RT-11
which was dated October 1998.

Does anyone else know if the V05.07 RT-11 Release Notes
manual is available as a PDF? If so, could it be added to
the bitsavers mirrors?

I have corrected the name of the PDF file and the link for the V05.07
RT-11 Release Notes. BUT I did not correct the text when I attempted
to send myself the e-mail to be sure that the link was correct.

Al Kossow JUST received the new PDF file for the V05.07 RT-11
Release Notes and placed them on the web site. OR, perhaps Tim
Shoppa placed them on the mirror for bitsavers.

In any case, the new PDF file name and the link are correct, the file
is NOW there and can be downloaded.

Jerome Fine

Re: PDF for RT-11 V05.07 Release Notes

2015-09-30 Thread Jerome H. Fine


>Jerome H. Fine wrote:


This request is for Al Kossow.  However, if anyone else knows
where AA-5286M-TC is located as a PDF on the internet, it
would be appreciated.

I have downloaded the V05.06 PDF from one of the mirrors:
AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.6_Aug91/AA-5286L-TC_RT-11_System_Release_Notes_Aug91.pdf 



THANK  YOU very much for making this PDF available.

However, I don't see the V05.07 PDF of the RT-11 Release
Notes anywhere.  If there is a copy, could you please provide
the link?

I presumed that if it existed, that PDF file would have been at:

AA-5286M-TC_RT-11_V5.7_Release_Notes_Oct98.pdf
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rt11/v5.7_Oct98/AA-5286M-TC_RT-11_V5.7_Release_Notes_Oct98.pdf 



but that sub-directory does not exist.

As I have mentioned in a previous post, the RT-11 DOC set
manuals for V05.06 and V05.07 are IDENTICAL except for:
AA-5286L-TC  RT-11 Release Notes for V05.06 of RT-11
which was dated August 1991 and
AA-5286M-TC  RT-11 Release Notes for V05.07 of RT-11
which was dated October 1998.

Does anyone else know if the V05.07 RT-11 Release Notes
manual is available as a PDF?  If so, could it be added to
the bitsavers mirrors?


Check

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

Just the whole idea of so many Linux distributions makes me bang my head
against the coffee table. One thing I greatly admire about the *BSD
projects has been the strong arm of unification, all contributors are
working towards one goal... It just so happened that Linux was the "free
UNIX that took off" (just like i386 was the "architecture that won") and we
have to live with the repercussions of that in IT ops every day for better
or for worse ... But that's just my two cents and no more ... I know this
topic can get religious! :O

Best,

Sean


On Wed, Sep 30, 2015 at 5:20 PM, Jay Jaeger  wrote:

> On 9/30/2015 3:13 PM, Liam Proven wrote:
> > On 30 September 2015 at 17:08, Noel Chiappa 
> wrote:
> >
> >> I am _very much_ in sympathy with the complaints here; I too feel that
> modern
> >> computers are too complex, etc. (Although some of it, like the entire
> computer
> >> turning into a single chip, were/are inevitable/unavoidable.)
> >
> > Indeed so.
> >
> >> I like the functionality of modern system, but I feel they are _more
> complex
> >> than they need to be_ to generate that level of functionality.
> >
> > Absolutely -- and there is a *lot* of legacy stuff that we could do
> > away with now.
> >
> > Even though I'm a former Red Hat employee, I have long favoured
> > Ubuntu. Fedora's always been way too bleeding-edge for me. However, I
> > approve of one change they made recently: they've merged /bin into
> > /usr/bin and /usr/sbin into /usr/sbin. I think they're merging
> > /usr/sbin and /usr/bin as well. The argument is that the root
> > filesystem is huge anyway, and there's no longer any benefit to having
> > them separated, the distinction not being clear in any case.
> >
>
> I generally agree about the distros - the issue for me wasn't so much
> that Fedora is "bleeding edge" but more that patch support only lasts
> around a year, as compared to Ubuntu LTS.
>
> As for the directories, some of what you wrote confused me a little
> (e.g. and /usr/sbin into /usr/sbin seems to be a NOP.  ;)  I suspect
> /sbin was supposed to appear in there somewhere...  ).
>
> Anyway, there was more to this than just the location of the
> directories.  The original idea of the "sbin" directories that they were
> only in root's path, and not in the path of ordinary users.  So one
> side-effect of this change will be commands that used to be less visible
> to ordinary users (and their command completion) will now be visible.
> Also, historically, /bin was that which was necessary for the system to
> boot and run - predates even the existence of the sbins.
>
> They had also better make sure that they put in links from the
> "deprecated" directories to where the stuff actually ended up, or they
> will break *tons* of shell scripts.
>
> Finally, I expect this will break a *ton* of ./configure scripts for
> software installation.
>
> Overall, I am not so sure this is such a great idea.
>
> JRJ
>

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

You can still have a useful machine without it being connected to the
public Internet. Network access is indeed very important, Internet
connectivity, less so.

I too rue the loss of simplicity ... and this has been voiced by many
people much more luminous than I ... Ken Thompson, for one, has commented
about the size and complexity in contemporary UNIX implementations ... This
is one reason why I love Plan 9 so much ... it takes you back a little bit
to when it was a pleasure to bang out a little code and you don't have to
deal with so much nonsense to get a little application that actually does
something, built.

Best,

Sean


On Wed, Sep 30, 2015 at 11:08 AM, Noel Chiappa 
wrote:

> > From: Liam Proven
>
> I am _very much_ in sympathy with the complaints here; I too feel that
> modern
> computers are too complex, etc. (Although some of it, like the entire
> computer
> turning into a single chip, were/are inevitable/unavoidable.)
>
> I like the functionality of modern system, but I feel they are _more
> complex
> than they need to be_ to generate that level of functionality.
>
> However, one thing I am going to quibble with:
>
> > This is a nice explanatory quote:
>
> >  The main reasons TempleOS is simple and beautiful are because it's
> >  ring-0-only .. Linux wants to be a secure, multi-user mainframe. ...
> >  It was simple, open and hackable. It was not networked. ... It was
> ^
> >  simple and unsecure. If you don't have malware and you don't have
> >  bugs, protection just slows things down and makes the code
> complicated.
>
> Note the part I highlighted. If you want to have a system that's
> network-capable, which is pretty much mandatory for a _really_ usable
> system
> in this day and age, i) that means Web-capable, and ii) if it's Web-capable
> today, it has to be able to handle what I dub 'active content' (JavaScript,
> etc) - i.e. content coming off the network which contains code, which runs
> in
> the local machine.
>
> To paraphrase a certain well-known SF work, IMO active content is probably
> the
> worst idea since humans' fore-fathers crawled out of the mud. It's
> _potentially_ a giant, gaping security hole - one that in today's OS's is
> responsible for a huge share of security issues. (There _is_ a way to have
> systems which aren't as vulnerable, but it means having military-grade
> security on everyone's machine - and no, I don't mean crypto; probably not
> likely, alas.) I mourn the early days of the Web, when there was no active
> content - just text, images, etc, etc. But no, they had to add all sorts of
> flashy eye candy - and did so in a way that makes basically all modern
> machines horribly insecure. But let me dispense with the soap box...
>
> Anyway, the inevitable consequence is that if you want a networked machine,
> it's _not_ going to be simple. Alas.
>
> You're basically sharing the machine with _lots_ of other people -
> effectively, every Tom, Dick and Jane out there in the Internet. In other
> words, you need everything one normally saw/sees in a time-sharing machine.
> (And I'm not talking about wimpy ones like Unix/Linux. I mean industrial
> strength ones like Multics.)
>
> Noel
>

Re: ESR Meter Recommendations

2015-09-30 Thread Tapley, Mark

I can put in another vote of confidence for this one. I have one from Portugal 
(because I didn’t know about the this-side-of-the-pond source) and it works as 
advertised.
- Mark


On Sep 30, 2015, at 12:54 PM, John Robertson  wrote:

> On 09/30/2015 7:14 AM, Jay West wrote:
>> John wrote
>> 
>> That is an authorized Bob Parker variation of his original Dick Smith ESR 
>> meter kit. On this side of the pond they were made by Anatek until the owner 
>> was killed in an accident, then the series (now called the Blue ESR) is made 
>> by Alltronics and sold by dealers such as I. These all use Bob's licensed 
>> code, just different box and PCB layouts.
>> 
>> If you want a Blue ESR I sell them on my web site's catalogue section, or 
>> you can order the EVB from Portugal if you are on the east side of the pond.
>> 
>> I've been selling variations (evolution by intelligent design) of Bob's ESR 
>> meter kit since 1999!
>> 
>> That is great info, thanks!
>> 
>> Question - I could be mistaken, but I think someone mentioned that these 
>> were not good for testing caps that had a higher operating voltage. Is that 
>> correct? My understanding was that the testing method used by this ESR meter 
>> was valid for most all the large electrolytics...?
>> 
>> J
>> 
>> 
> 
> As for testing large capacitors, about the highest value that gives useful 
> readings is around 10,000ufd. Larger than that and the ESR is too close to 
> zero ohms unless the cap is really bad...
> 
> One other unmentioned (I keep forgetting to add it to the list) benefit to 
> the meter is it does read down to 0.01 ohms which can be handy when looking 
> for shorts.
> 
> Blue ESR Kit Manual:
> 
> https://www.flippers.com/pdfs/BlueESR.pdf
> 
> John :-#)#
> 
> -- 
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com
> "Old pinballers never die, they just flip out"
>

Re: Active content [was Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers]

Plus a million. You can still view my personal page and get the full
experience in Netscape 2.0, Mosaic and so forth :O

Best,

Sean


On Wed, Sep 30, 2015 at 11:38 AM, Mouse  wrote:

> > If you want to have a system that's network-capable, which is pretty
> > much mandatory for a _really_ usable system in this day and age, i)
> > that means Web-capable, and ii) if it's Web-capable today, it has to
> > be able to handle what I dub 'active content' (JavaScript, etc) -
> > i.e. content coming off the network which contains code, which runs
> > in the local machine.
>
> Fortunately, neither part of that is actually true, unless you swallow
> today's mass-market propaganda that the Web is the Internet and the
> Internet is the Web, the Web is the One True Interface for anyone to
> anything, that the world is divided into content producers (large
> companies) and content consumers (end users), and that the consumer is
> obliged to tolerate whatever crap the producer feels like inflicting.
>
> As a refutation to part (i), I offer two of the computers on my desk
> today.  I don't know whether they're Web-capable, because I've never
> even tried to do anything Web with either one (I know they're
> HTTP-capable, but it's an abuse of HTTP, since it's used to transport
> config files rather than hypertext, and is not the Web).  As I have
> them configured, they speak SIP, RTP, FTP, and SNTP, and I think that's
> it.  I find them highly useful.  (Well, one of them's broken at the
> moment, but before it broke)
>
> As a refutation to part (ii), I point out that what little Web I do I
> do with lynx, which (as I have it set up) does not support any kind of
> active content - and I want it that way.
>
> Perhaps you feel you "need" to do things that can't be done within that
> paradigm.  If so, this is because of your idea of "usable", which not
> everyone shares.
>
> > To paraphrase a certain well-known SF work, IMO active content is
> > probably the worst idea since humans' fore-fathers crawled out of the
> > mud.
>
> I agree.  That's why I will have no truck with it.
>
> > I mourn the early days of the Web, when there was no active content -
> > just text, images, etc, etc.
>
> You can still live there, if you're willing to.  I am - and, watching
> over others' shoulders, I believe I am far happier this way than I
> would be if I had the likes of Facebook and YouTube infesting my
> "experience".  (I do wish I could find a copy of Mosaic source,
> though.)
>
> Of course, like everything, it comes at a price.  I find that price far
> lower than the prices that would be involved in putting up with today's
> mass-market Web.
>
> /~\ The ASCII Mouse
> \ / Ribbon Campaign
>  X  Against HTMLmo...@rodents-montreal.org
> / \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B
>

Re: ESR Meter Recommendations


On 09/30/2015 7:14 AM, Jay West wrote:

John wrote

That is an authorized Bob Parker variation of his original Dick Smith ESR meter 
kit. On this side of the pond they were made by Anatek until the owner was 
killed in an accident, then the series (now called the Blue ESR) is made by 
Alltronics and sold by dealers such as I. These all use Bob's licensed code, 
just different box and PCB layouts.

If you want a Blue ESR I sell them on my web site's catalogue section, or you 
can order the EVB from Portugal if you are on the east side of the pond.

I've been selling variations (evolution by intelligent design) of Bob's ESR 
meter kit since 1999!

That is great info, thanks!

Question - I could be mistaken, but I think someone mentioned that these were 
not good for testing caps that had a higher operating voltage. Is that correct? 
My understanding was that the testing method used by this ESR meter was valid 
for most all the large electrolytics...?

J




The only caveat is to discharge the capacitor first before testing. The 
meter does not like anything over 50VDC across the probes...tends to let 
the smoke out.


You can use the Blue ESR meter to check the internal resistance of 
batteries - I suspect one could use that info to build a chart of 
remaining life in a lead acid battery or ni-cad, but I never tried that.


Link for some background info:

http://flippers.com/BlueEsr.html

Sales...

http://www.flippers.com/catalog/product_info.php/blue-meter-p-2

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: ESR Meter Recommendations


On 09/30/2015 7:14 AM, Jay West wrote:

John wrote

That is an authorized Bob Parker variation of his original Dick Smith ESR meter 
kit. On this side of the pond they were made by Anatek until the owner was 
killed in an accident, then the series (now called the Blue ESR) is made by 
Alltronics and sold by dealers such as I. These all use Bob's licensed code, 
just different box and PCB layouts.

If you want a Blue ESR I sell them on my web site's catalogue section, or you 
can order the EVB from Portugal if you are on the east side of the pond.

I've been selling variations (evolution by intelligent design) of Bob's ESR 
meter kit since 1999!

That is great info, thanks!

Question - I could be mistaken, but I think someone mentioned that these were 
not good for testing caps that had a higher operating voltage. Is that correct? 
My understanding was that the testing method used by this ESR meter was valid 
for most all the large electrolytics...?

J




As for testing large capacitors, about the highest value that gives 
useful readings is around 10,000ufd. Larger than that and the ESR is too 
close to zero ohms unless the cap is really bad...


One other unmentioned (I keep forgetting to add it to the list) benefit 
to the meter is it does read down to 0.01 ohms which can be handy when 
looking for shorts.


Blue ESR Kit Manual:

https://www.flippers.com/pdfs/BlueESR.pdf

John :-#)#

--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
 www.flippers.com
"Old pinballers never die, they just flip out"

Re: ESR Meter Recommendations

2015-09-30 Thread Chris Elmquist

On Wednesday (09/30/2015 at 10:54AM -0700), John Robertson wrote:
> 
> As for testing large capacitors, about the highest value that gives useful
> readings is around 10,000ufd. Larger than that and the ESR is too close to
> zero ohms unless the cap is really bad...

And that seems to be the usual situation for most ESR meters.  How are
folks testing the very large electrolytics in the 25,000, 80,000 or even
100,000 uF range that are encountered in the power supplies of some of
these old machines?

One approach I use has been to isolate the supply and then fire it up
with an electronic load while looking at voltage sag and ripple on a
scope while that load is swept from min to max capability of the supply.

There is also the Sencore LC53 "Z Meter" which can test large caps up
to 200,000 uF out of circuit but these are typically a $400+ instrument
on the used market. 

http://bama.edebris.com/download/sencore/lc53/LC53%20OPS.pdf

Chris
-- 
Chris Elmquist NØJCF

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Jay Jaeger

On 9/30/2015 3:13 PM, Liam Proven wrote:
> On 30 September 2015 at 17:08, Noel Chiappa  wrote:
> 
>> I am _very much_ in sympathy with the complaints here; I too feel that modern
>> computers are too complex, etc. (Although some of it, like the entire 
>> computer
>> turning into a single chip, were/are inevitable/unavoidable.)
> 
> Indeed so.
> 
>> I like the functionality of modern system, but I feel they are _more complex
>> than they need to be_ to generate that level of functionality.
> 
> Absolutely -- and there is a *lot* of legacy stuff that we could do
> away with now.
> 
> Even though I'm a former Red Hat employee, I have long favoured
> Ubuntu. Fedora's always been way too bleeding-edge for me. However, I
> approve of one change they made recently: they've merged /bin into
> /usr/bin and /usr/sbin into /usr/sbin. I think they're merging
> /usr/sbin and /usr/bin as well. The argument is that the root
> filesystem is huge anyway, and there's no longer any benefit to having
> them separated, the distinction not being clear in any case.
> 

I generally agree about the distros - the issue for me wasn't so much
that Fedora is "bleeding edge" but more that patch support only lasts
around a year, as compared to Ubuntu LTS.

As for the directories, some of what you wrote confused me a little
(e.g. and /usr/sbin into /usr/sbin seems to be a NOP.  ;)  I suspect
/sbin was supposed to appear in there somewhere...  ).

Anyway, there was more to this than just the location of the
directories.  The original idea of the "sbin" directories that they were
only in root's path, and not in the path of ordinary users.  So one
side-effect of this change will be commands that used to be less visible
to ordinary users (and their command completion) will now be visible.
Also, historically, /bin was that which was necessary for the system to
boot and run - predates even the existence of the sbins.

They had also better make sure that they put in links from the
"deprecated" directories to where the stuff actually ended up, or they
will break *tons* of shell scripts.

Finally, I expect this will break a *ton* of ./configure scripts for
software installation.

Overall, I am not so sure this is such a great idea.

JRJ

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Liam Proven

On 30 September 2015 at 17:08, Noel Chiappa  wrote:

> I am _very much_ in sympathy with the complaints here; I too feel that modern
> computers are too complex, etc. (Although some of it, like the entire computer
> turning into a single chip, were/are inevitable/unavoidable.)

Indeed so.

> I like the functionality of modern system, but I feel they are _more complex
> than they need to be_ to generate that level of functionality.

Absolutely -- and there is a *lot* of legacy stuff that we could do
away with now.

Even though I'm a former Red Hat employee, I have long favoured
Ubuntu. Fedora's always been way too bleeding-edge for me. However, I
approve of one change they made recently: they've merged /bin into
/usr/bin and /usr/sbin into /usr/sbin. I think they're merging
/usr/sbin and /usr/bin as well. The argument is that the root
filesystem is huge anyway, and there's no longer any benefit to having
them separated, the distinction not being clear in any case.

> However, one thing I am going to quibble with:
>
> > This is a nice explanatory quote:
>
> >  The main reasons TempleOS is simple and beautiful are because it's
> >  ring-0-only .. Linux wants to be a secure, multi-user mainframe. ...
> >  It was simple, open and hackable. It was not networked. ... It was
> ^
> >  simple and unsecure. If you don't have malware and you don't have
> >  bugs, protection just slows things down and makes the code complicated.
>
> Note the part I highlighted. If you want to have a system that's
> network-capable, which is pretty much mandatory for a _really_ usable system
> in this day and age, i) that means Web-capable, and ii) if it's Web-capable
> today, it has to be able to handle what I dub 'active content' (JavaScript,
> etc) - i.e. content coming off the network which contains code, which runs in
> the local machine.

Mere point of reference: Acorn RISC OS still has a small active user
community. Its primary native web browsers, Oregano and NetSurf, don't
have a document object model and don't run Javascript. There's an
elderly port of Firefox but it's not maintained or current -- the hero
developer of the RISC OS Unix porting tools got a job in the states
and had to abandon the project, and in the insular world of RISC OS,
nobody else really understands the importance of it.

So, the old-fashioned pre-Web 2.0 WWW is still useful. More than you
might expect.

> To paraphrase a certain well-known SF work, IMO active content is probably the
> worst idea since humans' fore-fathers crawled out of the mud.

Just out of curiosity -- who? I can't place it.

> It's
> _potentially_ a giant, gaping security hole - one that in today's OS's is
> responsible for a huge share of security issues. (There _is_ a way to have
> systems which aren't as vulnerable, but it means having military-grade
> security on everyone's machine - and no, I don't mean crypto; probably not
> likely, alas.) I mourn the early days of the Web, when there was no active
> content - just text, images, etc, etc. But no, they had to add all sorts of
> flashy eye candy - and did so in a way that makes basically all modern
> machines horribly insecure. But let me dispense with the soap box...

All agreed with!

But OTOH a machine whose lowest level isn't a C-like language is in
principle immune to buffer overflows, stack-smashing, etc.

> Anyway, the inevitable consequence is that if you want a networked machine,
> it's _not_ going to be simple. Alas.

Conceded.

> You're basically sharing the machine with _lots_ of other people -
> effectively, every Tom, Dick and Jane out there in the Internet. In other
> words, you need everything one normally saw/sees in a time-sharing machine.
> (And I'm not talking about wimpy ones like Unix/Linux. I mean industrial
> strength ones like Multics.)

:-)

-- 
Liam Proven • Profile: http://lproven.livejournal.com/profile
Email: lpro...@cix.co.uk • GMail/G+/Twitter/Flickr/Facebook: lproven
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Re: ESR Meter Recommendations

2015-09-30 Thread Charles Anthony

On Wed, Sep 30, 2015 at 12:31 PM, ben  wrote:

> On 9/30/2015 12:24 PM, W2HX wrote:
>
>> Essentially these are two different measurements meant to measure a
>> different property of the capacitor. Capacitors have many properties,
>> many we know such as capacitance, working voltage, temp coefficient,
>> etc. Add to that list both leakage current (parallel resistance) and
>> ESR (series resistance). They tell you different things about the
>> capacitor's behavior.
>>
>> Hope this helps. Regards Eugene
>>
> Unless he's testing a flux capacitor...
>  roll that bench to 88 miles an hour



Since they made 3 of them, we can conclude that flux capacitors have low
ESR, yes?

-- Charles

Re: ESR Meter Recommendations

2015-09-30 Thread ben


On 9/30/2015 12:24 PM, W2HX wrote:

Essentially these are two different measurements meant to measure a
different property of the capacitor. Capacitors have many properties,
many we know such as capacitance, working voltage, temp coefficient,
etc. Add to that list both leakage current (parallel resistance) and
ESR (series resistance). They tell you different things about the
capacitor's behavior.

Hope this helps. Regards Eugene

Unless he's testing a flux capacitor...
 roll that bench to 88 miles an hour
Ben.

RE: ESR Meter Recommendations

2015-09-30 Thread W2HX

Essentially these are two different measurements meant to measure a different 
property of the capacitor. Capacitors have many properties, many we know such 
as capacitance, working voltage, temp coefficient, etc. Add to that list both 
leakage current (parallel resistance) and ESR (series resistance). They tell 
you different things about the capacitor's behavior.

Hope this helps.
Regards
Eugene

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Noel Chiappa
Sent: Wednesday, September 30, 2015 12:49 PM
To: cctalk@classiccmp.org
Cc: j...@mercury.lcs.mit.edu
Subject: Re: ESR Meter Recommendations

From: Eugene (W2HX)

> to model this using ideal components, we show a resistor in parallel to
> the capacitor ... This modeled parallel resistor represents the leakage
> current.
> ...
> because it is not ideal, some power is dissipated. This dissipated
> power is represented by a series resistance. Because an idealized
> circuit with a cap and a resistor in series will not pass DC current,
> this circuit must be tested at AC.

So I'm slightly confused; you talk about the model being a parallel resistor 
(which I get), but then switch to a series resistor. Why the switch?

Noel

Active content [was Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers]

2015-09-30 Thread Mouse

> If you want to have a system that's network-capable, which is pretty
> much mandatory for a _really_ usable system in this day and age, i)
> that means Web-capable, and ii) if it's Web-capable today, it has to
> be able to handle what I dub 'active content' (JavaScript, etc) -
> i.e. content coming off the network which contains code, which runs
> in the local machine.

Fortunately, neither part of that is actually true, unless you swallow
today's mass-market propaganda that the Web is the Internet and the
Internet is the Web, the Web is the One True Interface for anyone to
anything, that the world is divided into content producers (large
companies) and content consumers (end users), and that the consumer is
obliged to tolerate whatever crap the producer feels like inflicting.

As a refutation to part (i), I offer two of the computers on my desk
today.  I don't know whether they're Web-capable, because I've never
even tried to do anything Web with either one (I know they're
HTTP-capable, but it's an abuse of HTTP, since it's used to transport
config files rather than hypertext, and is not the Web).  As I have
them configured, they speak SIP, RTP, FTP, and SNTP, and I think that's
it.  I find them highly useful.  (Well, one of them's broken at the
moment, but before it broke)

As a refutation to part (ii), I point out that what little Web I do I
do with lynx, which (as I have it set up) does not support any kind of
active content - and I want it that way.

Perhaps you feel you "need" to do things that can't be done within that
paradigm.  If so, this is because of your idea of "usable", which not
everyone shares.

> To paraphrase a certain well-known SF work, IMO active content is
> probably the worst idea since humans' fore-fathers crawled out of the
> mud.

I agree.  That's why I will have no truck with it.

> I mourn the early days of the Web, when there was no active content -
> just text, images, etc, etc.

You can still live there, if you're willing to.  I am - and, watching
over others' shoulders, I believe I am far happier this way than I
would be if I had the likes of Facebook and YouTube infesting my
"experience".  (I do wish I could find a copy of Mosaic source,
though.)

Of course, like everything, it comes at a price.  I find that price far
lower than the prices that would be involved in putting up with today's
mass-market Web.

/~\ The ASCII Mouse
\ / Ribbon Campaign
 X  Against HTMLmo...@rodents-montreal.org
/ \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Noel Chiappa

> From: Liam Proven

I am _very much_ in sympathy with the complaints here; I too feel that modern
computers are too complex, etc. (Although some of it, like the entire computer
turning into a single chip, were/are inevitable/unavoidable.)

I like the functionality of modern system, but I feel they are _more complex
than they need to be_ to generate that level of functionality.

However, one thing I am going to quibble with:

> This is a nice explanatory quote:

>  The main reasons TempleOS is simple and beautiful are because it's
>  ring-0-only .. Linux wants to be a secure, multi-user mainframe. ...
>  It was simple, open and hackable. It was not networked. ... It was
^
>  simple and unsecure. If you don't have malware and you don't have
>  bugs, protection just slows things down and makes the code complicated.

Note the part I highlighted. If you want to have a system that's
network-capable, which is pretty much mandatory for a _really_ usable system
in this day and age, i) that means Web-capable, and ii) if it's Web-capable
today, it has to be able to handle what I dub 'active content' (JavaScript,
etc) - i.e. content coming off the network which contains code, which runs in
the local machine.

To paraphrase a certain well-known SF work, IMO active content is probably the
worst idea since humans' fore-fathers crawled out of the mud. It's
_potentially_ a giant, gaping security hole - one that in today's OS's is
responsible for a huge share of security issues. (There _is_ a way to have
systems which aren't as vulnerable, but it means having military-grade
security on everyone's machine - and no, I don't mean crypto; probably not
likely, alas.) I mourn the early days of the Web, when there was no active
content - just text, images, etc, etc. But no, they had to add all sorts of
flashy eye candy - and did so in a way that makes basically all modern
machines horribly insecure. But let me dispense with the soap box...

Anyway, the inevitable consequence is that if you want a networked machine,
it's _not_ going to be simple. Alas.

You're basically sharing the machine with _lots_ of other people -
effectively, every Tom, Dick and Jane out there in the Internet. In other
words, you need everything one normally saw/sees in a time-sharing machine.
(And I'm not talking about wimpy ones like Unix/Linux. I mean industrial
strength ones like Multics.)

Noel

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Liam Proven

On 30 September 2015 at 16:55, Eric Christopherson
 wrote:
>> The keyboard is one of these:
>>
>> http://www.computinghistory.org.uk/det/12269/LMT-68FX2-Keyboard-for-the-Spectrum/
>
> That's cool; but that is the strangest layout I've seen for arrow keys.

Yes, as I recall, it took a *lot* of getting used to, and never was great.

However, the keyboard was /massively/ better than the rubber-key
Spectrum, famously one of the worst keyboards ever made.

Which is why I'm mystified that people are now painstakingly
recreating the thing. You can buy a Bluetooth version now:

http://sinclair.recreatedzxspectrum.com/

And a cut-down miniaturised one with an ARM-based emulator inside:

http://retro-computers.co.uk/

-- 
Liam Proven • Profile: http://lproven.livejournal.com/profile
Email: lpro...@cix.co.uk • GMail/G+/Twitter/Flickr/Facebook: lproven
MSN: lpro...@hotmail.com • Skype/AIM/Yahoo/LinkedIn: liamproven
Cell/Mobiles: +44 7939-087884 (UK) • +420 702 829 053 (ČR)

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread David Williams



On 30/09/2015 15:55, Eric Christopherson wrote:
://www.computinghistory.org.uk/det/12269/LMT-68FX2-Keyboard-for-the-Spectrum/ 


That's cool; but that is the strangest layout I've seen for arrow keys.

This is a case for a ZX Spectrum. When it comes to anything Sinclair, 
strange is the norm!  :)

Re: A new Lisp-based OS that hearkens back to the old days of comprehensible computers

2015-09-30 Thread Eric Christopherson

On Wed, Sep 30, 2015 at 9:31 AM, Liam Proven  wrote:
> On 29 September 2015 at 19:06, SPC  wrote:
>> Very interesting. I must do an end-of-training project this year involving
>> Rapsberry Pi devices. Perhaps I'll give it a try.
>
>
> I just ordered a Pi 2, fitted inside a modified replacement keyboard
> for a ZX Spectrum that I found when packing up my house before leaving
> the UK. It's required a little bit of case modification to the
> keyboard, which is a slightly shame, but it was not particularly
> valuable and I have no other use for it.
>
> The keyboard is one of these:
>
> http://www.computinghistory.org.uk/det/12269/LMT-68FX2-Keyboard-for-the-Spectrum/

That's cool; but that is the strangest layout I've seen for arrow keys.

>
> And the conversion was done by Tynemouth Software:
>
> http://blog.tynemouthsoftware.co.uk/
>
> Dave Curran of Tynemouth refurbishes dead 8-bits either as USB
> keyboards for modern computers, or fits RasPis into them to bring them
> back to life.
>
> https://www.etsy.com/uk/shop/TynemouthSoftware

-- 
Eric Christopherson

Re: ESR Meter Recommendations