Dot allowed as characters allowed in netlist?

Den onsdag den 14. marts 2018 kl. 00.03.58 UTC+1 skrev Joerg:
> On 2018-03-13 15:11, Lasse Langwadt Christensen wrote:
> > Den tirsdag den 13. marts 2018 kl. 22.38.37 UTC+1 skrev Joerg:
> >> On 2018-03-13 08:43, John Larkin wrote:
> >>> On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
> >>> wrote:
> >>>
> >>>> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
> >>>>
> >>>>> The original justification was that decimal points were somehow
> >>>>> fragile and got lost on drawings, so the wrong parts values got
> >>>>> installed. It was nonsense of course.
> >>>>
> >>>> Too young to recall thermal fax machines?
> >>>> Lines that crossed got rather fat at the intersection,
> >>>> and the images faded over time.
> >>>
> >>> I started with hand-drawn schematics on vellum, and blueprint
> >>> machines. And I still use both. And I never lose or mistake decimal
> >>> points or tie points. Maybe that's because I had two semisters of
> >>> engineering drawing in college.
> >>>
> >>> I don't think that a D-size schematic could be FAXd, then or now.
> >>>
> >>> A lot of current "wisdom" is left over from olden days, and especially
> >>> bad, amateur habits of olden days. We have computers now. Parts lists
> >>> are generated automatically from our schematics, and computers don't
> >>> mistake decimal points for coffee stains. Software gets the net lists
> >>> right even when two wires cross.
> >>>
> >>
> >> I have found bugs in netlists. Mostly where wires looked like they
> >> connected to a component but didn't. I check every schematic on all my
> >> designs against the netlist by hand. Doing one right now. It's tedious
> >> grunt work but better safe that sorry.
> >
> > missing connections to a component should be caught by ERC
> >
> 
> Not if, for example, the pin is declared as output in the symbol because 
> leaving outputs unconnected is perfectly ok. Same for I/O or passive.

I have to put a "not connected" X on pins that aren't used

https://imgur.com/a/6zNk7

On 2018-03-13 16:15, John Larkin wrote:
> On Tue, 13 Mar 2018 15:57:28 -0700, Joerg <news@analogconsultants.com>
> wrote:
>
>> On 2018-03-13 15:36, John Larkin wrote:
>>> On Tue, 13 Mar 2018 22:38:57 +0100, Gerhard Hoffmann
>>> <gerhard@hoffmann-hochfrequenz.de> wrote:
>>>
>>>> Am 13.03.2018 um 22:20 schrieb Joerg:
>>>>
>>>>> It's worse. LTSpice cannot distinguish between milli and mega if you use
>>>>> m and M. It'll always see that as milli. You have to write MEG or e6,
>>>>> else it'll go wrong.
>>>>
>>>> That is the correct behavior. Changing that would break old decks
>>>> that used to work for 40 years.
>>>>
>>>> Gerhard
>>>
>>> 029 keypunch machines didn't have lowercase.
>>>
>>
>> :-))
>>
>> Almost spilled my glass of water here ...
>>
>> But yeah, got to keep the old stuff humming. We still fly DC-3's in the
>> US, profitably.
>
> "Deck" means "punched card deck." Punch cards were a huge improvement
> over paper tape.
>

That's how I learned the first steps in programming. The EE department 
of our university had only a few punch machines. The IBM's always worked 
but were always occupied. The Juki's conked out regularly so I always 
brought a tool kit, made sure no supervisors were around, repaired one 
and then got first dibs. The out of order sign had "casually fallen" to 
the floor.

-- 
Regards, Joerg

http://www.analogconsultants.com/

Am 13.03.2018 um 23:57 schrieb Joerg:
> On 2018-03-13 15:36, John Larkin wrote:
>> On Tue, 13 Mar 2018 22:38:57 +0100, Gerhard Hoffmann
>> <gerhard@hoffmann-hochfrequenz.de> wrote:
>>
>>> Am 13.03.2018 um 22:20 schrieb Joerg:
>>>
>>>> It's worse. LTSpice cannot distinguish between milli and mega if you 
>>>> use
>>>> m and M. It'll always see that as milli. You have to write MEG or e6,
>>>> else it'll go wrong.
>>>
>>> That is the correct behavior. Changing that would break old decks
>>> that used to work for 40 years.
>>>
>>> Gerhard
>>
>> 029 keypunch machines didn't have lowercase.
>>
> 
> :-))
> 
> Almost spilled my glass of water here ...
> 
> But yeah, got to keep the old stuff humming. We still fly DC-3's in the 
> US, profitably.
> 

I did learn Fortran and Spice on 029 keypunches. :-)

And it's not only old libraries. There are also
spice back ends in circuit and parasitic extractors
from chip layout that work for eons and that nobody
will want to touch again. Not for an ambiguity that
is arbitrarily created.

On 2018-03-13 16:47, Gerhard Hoffmann wrote:
> Am 13.03.2018 um 23:57 schrieb Joerg:
>> On 2018-03-13 15:36, John Larkin wrote:
>>> On Tue, 13 Mar 2018 22:38:57 +0100, Gerhard Hoffmann
>>> <gerhard@hoffmann-hochfrequenz.de> wrote:
>>>
>>>> Am 13.03.2018 um 22:20 schrieb Joerg:
>>>>
>>>>> It's worse. LTSpice cannot distinguish between milli and mega if
>>>>> you use
>>>>> m and M. It'll always see that as milli. You have to write MEG or e6,
>>>>> else it'll go wrong.
>>>>
>>>> That is the correct behavior. Changing that would break old decks
>>>> that used to work for 40 years.
>>>>
>>>> Gerhard
>>>
>>> 029 keypunch machines didn't have lowercase.
>>>
>>
>> :-))
>>
>> Almost spilled my glass of water here ...
>>
>> But yeah, got to keep the old stuff humming. We still fly DC-3's in
>> the US, profitably.
>>
>
> I did learn Fortran and Spice on 029 keypunches. :-)
>
> And it's not only old libraries. There are also
> spice back ends in circuit and parasitic extractors
> from chip layout that work for eons and that nobody
> will want to touch again. Not for an ambiguity that
> is arbitrarily created.
>

Often they can't anymore because the guys who created these are in 
nursing homes or no longer on earth. Sometimes part of the (mental) 
documentation goes with them into their grave.

I just had my comeuppance regarding "modernization". I recently updated 
recently and some of my RF sim files no longer worked. Even after 
re-creating the symbols they axed I get the message "This schematic uses 
symbols that couldn't be found. Saving it will remove reference to these 
symbols from the schematic!" and then there isn't anything removed. The 
message doesn't always show. Something must have been broken.

-- 
Regards, Joerg

http://www.analogconsultants.com/

On Tue, 13 Mar 2018 14:38:35 -0700, Joerg <news@analogconsultants.com>
wrote:

>On 2018-03-13 08:43, John Larkin wrote:
>> On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
>> wrote:
>>
>>> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
>>>
>>>> The original justification was that decimal points were somehow
>>>> fragile and got lost on drawings, so the wrong parts values got
>>>> installed. It was nonsense of course.
>>>
>>> Too young to recall thermal fax machines?
>>> Lines that crossed got rather fat at the intersection,
>>> and the images faded over time.
>>
>> I started with hand-drawn schematics on vellum, and blueprint
>> machines. And I still use both. And I never lose or mistake decimal
>> points or tie points. Maybe that's because I had two semisters of
>> engineering drawing in college.
>>
>> I don't think that a D-size schematic could be FAXd, then or now.
>>
>> A lot of current "wisdom" is left over from olden days, and especially
>> bad, amateur habits of olden days. We have computers now. Parts lists
>> are generated automatically from our schematics, and computers don't
>> mistake decimal points for coffee stains. Software gets the net lists
>> right even when two wires cross.
>>
>
>I have found bugs in netlists. Mostly where wires looked like they 
>connected to a component but didn't. I check every schematic on all my 
>designs against the netlist by hand. Doing one right now. It's tedious 
>grunt work but better safe that sorry.
>
>On the last one I found a bug that was my fault. The eye sight isn't 
>getting better and I thought one node was connected to -12V where in 
>reality it was +12V. Going through the netlist that jumped right at me 
>... whew.

I had one, some years ago (and I'm using the board again now) where
the datasheet for an audio amplifier had pins labeled Vcc+ and Vcc-.
So, not thinking, I connected the Vcc+ pins to the most positive rail
(+12V) and Vcc- to the most negative rail (ground).  Nerp!  Vcc+ was
fine but the Vcc- pins were the Vcc pins for the "negative" half
bridge.  They were both supposed to go to the positive rail.
Fortunately, the pins were adjacent and it was a QFP part, so the pins
could lifted and moved over to the adjacent pins.  The netlist didn't
help (though it has in the past).

>Down to my last crayon pencil now. It is still from my old 1st grade kit 
>and I thought they'd last until retirement. A new set of 12 is en route 
>from China, $1.87 free ship, couldn't believe it. That should last me 
>for netlist checks until I am 120.
>
>
>> Scientific notation and SI units are correct. The 4K7 thing is amateur
>> audio nonsense.
>>
>
>It was worse in the old days. Often a schematic said .001 with no units 
>whatsoever and you had to guess from the function of the circuit what 
>that meant. Not a problem for us seasoned guys but that could throw 
>freshly minted engineers a curve.

There was usually a note that said something like "all capacitance
values in microfarads and all resistance values in k-ohms, unless
otherwise noted).

On Tue, 13 Mar 2018 15:11:04 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

>Den tirsdag den 13. marts 2018 kl. 22.38.37 UTC+1 skrev Joerg:
>> On 2018-03-13 08:43, John Larkin wrote:
>> > On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
>> > wrote:
>> >
>> >> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
>> >>
>> >>> The original justification was that decimal points were somehow
>> >>> fragile and got lost on drawings, so the wrong parts values got
>> >>> installed. It was nonsense of course.
>> >>
>> >> Too young to recall thermal fax machines?
>> >> Lines that crossed got rather fat at the intersection,
>> >> and the images faded over time.
>> >
>> > I started with hand-drawn schematics on vellum, and blueprint
>> > machines. And I still use both. And I never lose or mistake decimal
>> > points or tie points. Maybe that's because I had two semisters of
>> > engineering drawing in college.
>> >
>> > I don't think that a D-size schematic could be FAXd, then or now.
>> >
>> > A lot of current "wisdom" is left over from olden days, and especially
>> > bad, amateur habits of olden days. We have computers now. Parts lists
>> > are generated automatically from our schematics, and computers don't
>> > mistake decimal points for coffee stains. Software gets the net lists
>> > right even when two wires cross.
>> >
>> 
>> I have found bugs in netlists. Mostly where wires looked like they 
>> connected to a component but didn't. I check every schematic on all my 
>> designs against the netlist by hand. Doing one right now. It's tedious 
>> grunt work but better safe that sorry.
>
>missing connections to a component should be caught by ERC

"Should".  I agree.  However, depending on the schematic capture
package...

>> 
>> On the last one I found a bug that was my fault. The eye sight isn't 
>> getting better and I thought one node was connected to -12V where in 
>> reality it was +12V. Going through the netlist that jumped right at me 
>> ... whew.
>
>that is hard to catch, sorta a like spellchecker can't pick the right word 
>for you 

His point is well taken, though.  A nicely formatted netlist can show
a lot of errors.  It's worth a good look.

On Tue, 13 Mar 2018 15:33:12 -0700, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

>On Tue, 13 Mar 2018 15:11:04 -0700 (PDT), Lasse Langwadt Christensen
><langwadt@fonz.dk> wrote:
>
>>Den tirsdag den 13. marts 2018 kl. 22.38.37 UTC+1 skrev Joerg:
>>> On 2018-03-13 08:43, John Larkin wrote:
>>> > On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
>>> > wrote:
>>> >
>>> >> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
>>> >>
>>> >>> The original justification was that decimal points were somehow
>>> >>> fragile and got lost on drawings, so the wrong parts values got
>>> >>> installed. It was nonsense of course.
>>> >>
>>> >> Too young to recall thermal fax machines?
>>> >> Lines that crossed got rather fat at the intersection,
>>> >> and the images faded over time.
>>> >
>>> > I started with hand-drawn schematics on vellum, and blueprint
>>> > machines. And I still use both. And I never lose or mistake decimal
>>> > points or tie points. Maybe that's because I had two semisters of
>>> > engineering drawing in college.
>>> >
>>> > I don't think that a D-size schematic could be FAXd, then or now.
>>> >
>>> > A lot of current "wisdom" is left over from olden days, and especially
>>> > bad, amateur habits of olden days. We have computers now. Parts lists
>>> > are generated automatically from our schematics, and computers don't
>>> > mistake decimal points for coffee stains. Software gets the net lists
>>> > right even when two wires cross.
>>> >
>>> 
>>> I have found bugs in netlists. Mostly where wires looked like they 
>>> connected to a component but didn't. I check every schematic on all my 
>>> designs against the netlist by hand. Doing one right now. It's tedious 
>>> grunt work but better safe that sorry.
>>
>>missing connections to a component should be caught by ERC
>
>How does that work?

Nothing connected to the pin, maybe?

Am 14.03.2018 um 00:29 schrieb Joerg:

> That's how I learned the first steps in programming. The EE department 
> of our university had only a few punch machines. The IBM's always worked 
> but were always occupied. The Juki's conked out regularly so I always 
> brought a tool kit, made sure no supervisors were around, repaired one 
> and then got first dibs. The out of order sign had "casually fallen" to 
> the floor.
> 

Some of us EE students were even officially allowed to operate
the TR4 alone, outside the business hours.

So, in a sense, the TR4 was my first personal computer, with
card readers, mag tapes, disks, chain printer and a neon lamp
for every register bit.

It had 48 bit word size, quite an illumination.   :-)


Gerhard

On Tue, 13 Mar 2018 16:03:57 -0700, Joerg <news@analogconsultants.com>
wrote:

>On 2018-03-13 15:11, Lasse Langwadt Christensen wrote:
>> Den tirsdag den 13. marts 2018 kl. 22.38.37 UTC+1 skrev Joerg:
>>> On 2018-03-13 08:43, John Larkin wrote:
>>>> On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
>>>> wrote:
>>>>
>>>>> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
>>>>>
>>>>>> The original justification was that decimal points were somehow
>>>>>> fragile and got lost on drawings, so the wrong parts values got
>>>>>> installed. It was nonsense of course.
>>>>>
>>>>> Too young to recall thermal fax machines?
>>>>> Lines that crossed got rather fat at the intersection,
>>>>> and the images faded over time.
>>>>
>>>> I started with hand-drawn schematics on vellum, and blueprint
>>>> machines. And I still use both. And I never lose or mistake decimal
>>>> points or tie points. Maybe that's because I had two semisters of
>>>> engineering drawing in college.
>>>>
>>>> I don't think that a D-size schematic could be FAXd, then or now.
>>>>
>>>> A lot of current "wisdom" is left over from olden days, and especially
>>>> bad, amateur habits of olden days. We have computers now. Parts lists
>>>> are generated automatically from our schematics, and computers don't
>>>> mistake decimal points for coffee stains. Software gets the net lists
>>>> right even when two wires cross.
>>>>
>>>
>>> I have found bugs in netlists. Mostly where wires looked like they
>>> connected to a component but didn't. I check every schematic on all my
>>> designs against the netlist by hand. Doing one right now. It's tedious
>>> grunt work but better safe that sorry.
>>
>> missing connections to a component should be caught by ERC
>>
>
>Not if, for example, the pin is declared as output in the symbol because 
>leaving outputs unconnected is perfectly ok. Same for I/O or passive.

These pins should (have to) be marked as not connected.  

>>> On the last one I found a bug that was my fault. The eye sight isn't
>>> getting better and I thought one node was connected to -12V where in
>>> reality it was +12V. Going through the netlist that jumped right at me
>>> ... whew.
>>
>> that is hard to catch, sorta a like spellchecker can't pick the right word
>> for you
>>
>
>Operator error is one of the reasons why I will always hand-check 
>netlists after finishing a circuit design. Bugs in CAD systems are the 
>other.
>
>Today's netlist went through sans error. Those color pencils really seem 
>to be made only for kids. It says name, class and school on the box, in 
>Chinese.

On Tue, 13 Mar 2018 20:15:03 -0400, krw@notreal.com wrote:

>On Tue, 13 Mar 2018 15:33:12 -0700, John Larkin
><jjlarkin@highland_snip_technology.com> wrote:
>
>>On Tue, 13 Mar 2018 15:11:04 -0700 (PDT), Lasse Langwadt Christensen
>><langwadt@fonz.dk> wrote:
>>
>>>Den tirsdag den 13. marts 2018 kl. 22.38.37 UTC+1 skrev Joerg:
>>>> On 2018-03-13 08:43, John Larkin wrote:
>>>> > On Mon, 12 Mar 2018 17:43:07 -0700 (PDT), whit3rd <whit3rd@gmail.com>
>>>> > wrote:
>>>> >
>>>> >> On Sunday, March 11, 2018 at 1:59:26 PM UTC-7, John Larkin wrote:
>>>> >>
>>>> >>> The original justification was that decimal points were somehow
>>>> >>> fragile and got lost on drawings, so the wrong parts values got
>>>> >>> installed. It was nonsense of course.
>>>> >>
>>>> >> Too young to recall thermal fax machines?
>>>> >> Lines that crossed got rather fat at the intersection,
>>>> >> and the images faded over time.
>>>> >
>>>> > I started with hand-drawn schematics on vellum, and blueprint
>>>> > machines. And I still use both. And I never lose or mistake decimal
>>>> > points or tie points. Maybe that's because I had two semisters of
>>>> > engineering drawing in college.
>>>> >
>>>> > I don't think that a D-size schematic could be FAXd, then or now.
>>>> >
>>>> > A lot of current "wisdom" is left over from olden days, and especially
>>>> > bad, amateur habits of olden days. We have computers now. Parts lists
>>>> > are generated automatically from our schematics, and computers don't
>>>> > mistake decimal points for coffee stains. Software gets the net lists
>>>> > right even when two wires cross.
>>>> >
>>>> 
>>>> I have found bugs in netlists. Mostly where wires looked like they 
>>>> connected to a component but didn't. I check every schematic on all my 
>>>> designs against the netlist by hand. Doing one right now. It's tedious 
>>>> grunt work but better safe that sorry.
>>>
>>>missing connections to a component should be caught by ERC
>>
>>How does that work?
>
>Nothing connected to the pin, maybe?

I meant, what is ERC?


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com