LTSpice Automation

[legg]

On Wed, 17 Feb 2010 15:33:11 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I


Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...


You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?

They were still torturing tech students that way in the 80s.

RL

 

[Joerg]

Jim Thompson wrote:

On Wed, 17 Feb 2010 16:51:58 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency
that Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I
couldn't have done it...

You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA
card. I had the deluxe edition, a CRT in nicotine-yellow

Well, I did lots of *real design* before committing spice, which
happened on the late, maybe 10 years ago...

I often do complicated projects where many design options have to be
studied, and when the GUI stands in the way, it's a no-no.

The small sensor I'm finishing right now is a good example.
As was also the PSU that powers the DUTs on testers used to wafer
test the INTEL and AMD CPUs. (Yep, all your nice CPUs are tested by
my design

I always knew that the Romans never completely subdued you guys and
you'd come back


When I did that (circa 2000) I estimated it would have taken 3 to 4
more time on the design pass with another spice, not even speaking of
LTspice.

Much of my stuff can't even possibly be simulated. Like a lot of
transducers.

Sure it can. Well, most of it. That's just a matter of model development
and will it pay back to do so or not. And when it's done, it's done

We are doing that as I write this, or rather, a client does. But it has
its limits. If you want to perfect it you may slip the time-to-market
schedule too much. In the old days it was even worse, once we blew up a
Pentium-I during a sim (back when those were just out and really
expensive). The client wasn't exactly happy when that happened.


I usually have big time developing adequate models (well, less and less
since I now have plenty). Then, with realistic models you gain a lot of
insight and have much better designs with less bench work.
For ex. it's easier to measure components at high temp, use spice and
have it right first time, than discovering pbs when baking the proto,
even without saying that investigating at high temp is slow and painful.

If you design super small stuff with lots of electronics, yes. Poring
over one of those right now, custom chips with a few hundred channels
that must fit into a little less than 2.5mm diameter tube. Flip-chip
bonding these will be fun.

I didn't do ANY simulation until around 1977-78. Prior to that was
all hand drawings and math solving; and bread-boarding... so that
covers all of my Motorola standard I/C products without a single
simulation.

I still "think by hand", but I don't know how you can get by without a
simulator when you're talking literally thousands of transistors.

This one will have tens of thousands ...

<bead of sweat dropping off forehead>

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Phil Hobbs]

On 2/17/2010 7:35 PM, Joerg wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 16:10:13 -0800, Joerg <invalid@invalid.invalid
wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency
that Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I
couldn't have done it...

You guys are spoiled, or too young. Back when I started the "GUI"
of PSpice consisted of a rather small green CRT hanging off some
CGA card. I had the deluxe edition, a CRT in nicotine-yellow
Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?

A friend of mine tried this with a Commodore daisy wheel printer,
same that I used to have. It could do microstepping and he just used
the dot. Which consequently wore out real fast ...

My first forays in to computing was writing Fortran. Using a Juki
punch card machine.

Summer of 1961 I took a sequence of courses on the Institute's first
transistorized mainframe (IIRC IBM 709 ?), FAP (machine language) and
FORTRAN... lots of punched cards... don't drop your stack ;-)


Old trick: _Immediately_ number the cards after taking off the machine.
Else on turfing during the bicycle ride and it's all over.

You guys obviously went to the wrong school. We just shoved the cards
through the verifier, and it not only numbered but decoded and printed
them. Of course that was 1977, and I was the last one using cards at
the entire school--I thought they were fun and didn't want to miss the
party.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs at electrooptical dot net
http://electrooptical.net

 

[Jim Thompson]

On Wed, 17 Feb 2010 17:37:57 -0800, Joerg <invalid@invalid.invalid>
wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 16:51:58 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency
that Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I
couldn't have done it...

You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA
card. I had the deluxe edition, a CRT in nicotine-yellow

Well, I did lots of *real design* before committing spice, which
happened on the late, maybe 10 years ago...

I often do complicated projects where many design options have to be
studied, and when the GUI stands in the way, it's a no-no.

The small sensor I'm finishing right now is a good example.
As was also the PSU that powers the DUTs on testers used to wafer
test the INTEL and AMD CPUs. (Yep, all your nice CPUs are tested by
my design

I always knew that the Romans never completely subdued you guys and
you'd come back


When I did that (circa 2000) I estimated it would have taken 3 to 4
more time on the design pass with another spice, not even speaking of
LTspice.

Much of my stuff can't even possibly be simulated. Like a lot of
transducers.

Sure it can. Well, most of it. That's just a matter of model development
and will it pay back to do so or not. And when it's done, it's done

We are doing that as I write this, or rather, a client does. But it has
its limits. If you want to perfect it you may slip the time-to-market
schedule too much. In the old days it was even worse, once we blew up a
Pentium-I during a sim (back when those were just out and really
expensive). The client wasn't exactly happy when that happened.


I usually have big time developing adequate models (well, less and less
since I now have plenty). Then, with realistic models you gain a lot of
insight and have much better designs with less bench work.
For ex. it's easier to measure components at high temp, use spice and
have it right first time, than discovering pbs when baking the proto,
even without saying that investigating at high temp is slow and painful.

If you design super small stuff with lots of electronics, yes. Poring
over one of those right now, custom chips with a few hundred channels
that must fit into a little less than 2.5mm diameter tube. Flip-chip
bonding these will be fun.

I didn't do ANY simulation until around 1977-78. Prior to that was
all hand drawings and math solving; and bread-boarding... so that
covers all of my Motorola standard I/C products without a single
simulation.

I still "think by hand", but I don't know how you can get by without a
simulator when you're talking literally thousands of transistors.


This one will have tens of thousands ...

bead of sweat dropping off forehead

Characterize, then convert the digital to behavioral models, then
it'll be easy ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[legg]

On Mon, 15 Feb 2010 16:30:09 -0600, Tim Wescott <tim@seemywebsite.com>
wrote:

Does LTSpice have much in the way of automation capabilities?

I'm working on a switcher design, half in mathemagic land, half in grotty
old real circuits land -- I want to simulate the controller with PWM
voltages, and look at how the circuit responds. So I'd like to run the
circuit with a bunch of different duty cycles. But it's a complex
circuit, so I need a bunch of different PWM's, all synchronized
together. Is there a way to get LTSpice to carry a variable, use that
variable in it's .trans card, and either set it once and run a
simulation, or (better) run a simulation from the command line?

OK, so now that we've all found the help files, can anyone explain
what a 'global parameter' is, and how do you make a simulation swallow
a .step param xxx statement for a specific component?

RL

 

[JosephKK]

On Wed, 17 Feb 2010 12:14:27 -0800, Fred Abse <excretatauris@invalid.invalid> wrote:

On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I

OOOPS!

And thanks again, i am getting my Fourier analyses and THD numbers versus load now.

 

[JosephKK]

On Wed, 17 Feb 2010 15:33:11 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I


Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...


You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?

...Jim Thompson

Yep, but my spice versions were ISspice 1.94 and ISSpice 386/4
I also had tabular numeric data. Core engine Spice 2f4 and 2g6 IIRC.

 

[JosephKK]

On Wed, 17 Feb 2010 17:31:31 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

On Wed, 17 Feb 2010 16:10:13 -0800, Joerg <invalid@invalid.invalid
wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...

You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?


A friend of mine tried this with a Commodore daisy wheel printer, same
that I used to have. It could do microstepping and he just used the dot.
Which consequently wore out real fast ...

My first forays in to computing was writing Fortran. Using a Juki punch
card machine.

Summer of 1961 I took a sequence of courses on the Institute's first
transistorized mainframe (IIRC IBM 709 ?), FAP (machine language) and
FORTRAN... lots of punched cards... don't drop your stack ;-)

...Jim Thompson

I quickly got the habit of carrying them with three fresh rubber bands
holding them together, in order. Plus small stacks in envelopes, and
large stacks in boxes.

 

[Jim Thompson]

On Wed, 17 Feb 2010 21:06:56 -0500, legg <legg@nospam.magma.ca> wrote:

On Mon, 15 Feb 2010 16:30:09 -0600, Tim Wescott <tim@seemywebsite.com
wrote:

Does LTSpice have much in the way of automation capabilities?

I'm working on a switcher design, half in mathemagic land, half in grotty
old real circuits land -- I want to simulate the controller with PWM
voltages, and look at how the circuit responds. So I'd like to run the
circuit with a bunch of different duty cycles. But it's a complex
circuit, so I need a bunch of different PWM's, all synchronized
together. Is there a way to get LTSpice to carry a variable, use that
variable in it's .trans card, and either set it once and run a
simulation, or (better) run a simulation from the command line?


OK, so now that we've all found the help files, can anyone explain
what a 'global parameter' is, and how do you make a simulation swallow
a .step param xxx statement for a specific component?

RL

In PSpice, you must first "declare" the parameter, very much C-like.

While don't you pursue this in the LTspice Yahoo Group?

I subscribe to their daily digests... lots of good stuff there, even
for non-LTspice users.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Joel Koltner]

"Tim Williams" <tmoranwms@charter.net> wrote in message
news:hlhqvs$cte$1@news.eternal-september.org...

I'm astonished that the book is only 1989, and not older!

Those text-mode graphs persisted until the mid-'90s and perhaps even late-'90s
at times -- particularly at schools where there's sometimes not the budget or
personnel to upgrade the software. In the early '90s while I was an
undergraduate, some of the grad students were still actively writing new
software for PDP-11s...

 

[Joerg]

Jim Thompson wrote:

On Wed, 17 Feb 2010 17:37:57 -0800, Joerg <invalid@invalid.invalid
wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 16:51:58 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Joerg a écrit :
Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency
that Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I
couldn't have done it...

You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA
card. I had the deluxe edition, a CRT in nicotine-yellow

Well, I did lots of *real design* before committing spice, which
happened on the late, maybe 10 years ago...

I often do complicated projects where many design options have to be
studied, and when the GUI stands in the way, it's a no-no.

The small sensor I'm finishing right now is a good example.
As was also the PSU that powers the DUTs on testers used to wafer
test the INTEL and AMD CPUs. (Yep, all your nice CPUs are tested by
my design
I always knew that the Romans never completely subdued you guys and
you'd come back


When I did that (circa 2000) I estimated it would have taken 3 to 4
more time on the design pass with another spice, not even speaking of
LTspice.

Much of my stuff can't even possibly be simulated. Like a lot of
transducers.

Sure it can. Well, most of it. That's just a matter of model development
and will it pay back to do so or not. And when it's done, it's done

We are doing that as I write this, or rather, a client does. But it has
its limits. If you want to perfect it you may slip the time-to-market
schedule too much. In the old days it was even worse, once we blew up a
Pentium-I during a sim (back when those were just out and really
expensive). The client wasn't exactly happy when that happened.


I usually have big time developing adequate models (well, less and less
since I now have plenty). Then, with realistic models you gain a lot of
insight and have much better designs with less bench work.
For ex. it's easier to measure components at high temp, use spice and
have it right first time, than discovering pbs when baking the proto,
even without saying that investigating at high temp is slow and painful.

If you design super small stuff with lots of electronics, yes. Poring
over one of those right now, custom chips with a few hundred channels
that must fit into a little less than 2.5mm diameter tube. Flip-chip
bonding these will be fun.
I didn't do ANY simulation until around 1977-78. Prior to that was
all hand drawings and math solving; and bread-boarding... so that
covers all of my Motorola standard I/C products without a single
simulation.

I still "think by hand", but I don't know how you can get by without a
simulator when you're talking literally thousands of transistors.

This one will have tens of thousands ...

bead of sweat dropping off forehead

Characterize, then convert the digital to behavioral models, then
it'll be easy ;-)

It's not digital, the digital parts are a piece of cake :-(

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Fred Abse]

On Wed, 17 Feb 2010 14:25:26 -0800, Joerg wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I


Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...


You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Back when I started, a GUI was a foot long, and made of wood ;-)

First network analysis software I had, I wrote myself. A node-admittance
matrix thingy using LU decomposition, in TRS-80 BASIC. Still no GUI.

I still use Berkeley Spice 3f4 occasionally, 'cos it'll do things LTSpice
won't,like PZ analysis.

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)

 

[Fred Abse]

On Wed, 17 Feb 2010 15:33:11 -0700, Jim Thompson wrote:

On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I


Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...


You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?

Yup.

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)

 

[krw]

On Wed, 17 Feb 2010 16:10:13 -0800, Joerg <invalid@invalid.invalid>
wrote:

Jim Thompson wrote:
On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.
T'warn't Fred Bartoli,t'was I

Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...

You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?


A friend of mine tried this with a Commodore daisy wheel printer, same
that I used to have. It could do microstepping and he just used the dot.
Which consequently wore out real fast ...

When I first started with IBM, we used communicating Selectrics and
2741s (a bullet-proofed Selectric sort of thing) for this. Overnight
runs used a different simulator and chain printers. The printing was
the same as above, though, and printouts were often a foot thick.

My first forays in to computing was writing Fortran. Using a Juki punch
card machine.

We used IBM 029s in high school and college with a 360/75 (amazing
beast) at the business end.

 

[krw]

On Wed, 17 Feb 2010 20:15:04 -0500, legg <legg@nospam.magma.ca> wrote:

On Wed, 17 Feb 2010 15:33:11 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

On Wed, 17 Feb 2010 14:25:26 -0800, Joerg <invalid@invalid.invalid
wrote:

Fred Bartoli wrote:
Fred Abse a écrit :
On Wed, 17 Feb 2010 07:26:20 -0800, JosephKK wrote:

Geez, did everybody forget the three phase rectifier efficiency that
Fred Bartoli did for me? Note the stepped load on the right.

T'warn't Fred Bartoli,t'was I


Oh, I thought even I forgot about it

Well, I don't use much LTspice thanks to its poor GUI, so I couldn't
have done it...


You guys are spoiled, or too young. Back when I started the "GUI" of
PSpice consisted of a rather small green CRT hanging off some CGA card.
I had the deluxe edition, a CRT in nicotine-yellow

Sheeeesh! When I started using Spice I drew schematics on paper pads,
numbered the nodes, typed in the netlist and ran it under DOS.

Aaron eased my pain by writing a pre/post version controller which
numbered all the .CIR and .DAT files so I could keep track of all the
changes.

Data spewed forth from a tractor feed printer:

.001 *
.002 *
.003 *
.004 *

etc. Anyone else remember those days?

They were still torturing tech students that way in the 80s.

Didn't everyone have PCs by then?

 

[Joel Koltner]

"krw" <krw@att.bizzzzzzzzzzz> wrote in message
news:rtkrn51hvfcfm17cjrvhp0uf9o81koupr0@4ax.com...

Didn't everyone have PCs by then?

In 1994, when I received my BSEE, of the engineering students I knew, I doubt
that even half had their own PCs. That was still the era of very large
computer labs -- I took some computer science class to learn C, Pascal, and
FORTRAN (probably in 1992), and while I had a good enough job that I could
afford to buy copies of Turbo C and Turbo Pascal for DOS, I knew FORTRAN was a
pretty dead language already and used the college's computer lab. FORTRAN was
taught on Macs and the main lab was a huge, poorly-ventilated room in the
basement of a ugly concrete building with literally hundreds of Macs and
students side-by-side. It wasn't exactly a nice atmosphere!

The next semester I took "assembly langauge on a VAX" -- a room of a couple
dozen terminals, much more room per student -- and "data structures and
algorithms" -- a room of perhaps 50 HP PA-RISC workstations running HPUX --,
and those were actually pretty nice environments.

I had an Amiga 3000 at the time... and while Berkeley SPICE was available, the
guys with PCs were already running the free version of PSpice which had much
better graphing abilities.

Laptops were quite new and insanely expensive (and machines mere mortals could
afford had the crappy highly-multiplexed monochrome LCDs). How far we've
come -- today I'd wager >99% of engineering students have PCs, almost all of
those are laptops (all active-matrix LCDs now), and nearly all campuses have
ubiquitous WFi.

---Joel

 

[Joel Koltner]

Thinking back, at the time a desktop PC still cost the equivalent of perhaps
30 college textbooks. Today, a reasonable laptop is perhaps all of 5...!

 

[krw]

On Thu, 18 Feb 2010 16:39:51 -0800, "Joel Koltner"
<zapwireDASHgroups@yahoo.com> wrote:

"krw" <krw@att.bizzzzzzzzzzz> wrote in message
news:rtkrn51hvfcfm17cjrvhp0uf9o81koupr0@4ax.com...
Didn't everyone have PCs by then?

In 1994, when I received my BSEE, of the engineering students I knew, I doubt
that even half had their own PCs.

Amazing. Where did you go to school?

That was still the era of very large
computer labs -- I took some computer science class to learn C, Pascal, and
FORTRAN (probably in 1992), and while I had a good enough job that I could
afford to buy copies of Turbo C and Turbo Pascal for DOS, I knew FORTRAN was a
pretty dead language already and used the college's computer lab. FORTRAN was
taught on Macs and the main lab was a huge, poorly-ventilated room in the
basement of a ugly concrete building with literally hundreds of Macs and
students side-by-side. It wasn't exactly a nice atmosphere!

Being forced to sit in a room full of Mac-heads? ...I can only
imagine. ;-)

The next semester I took "assembly langauge on a VAX" -- a room of a couple
dozen terminals, much more room per student -- and "data structures and
algorithms" -- a room of perhaps 50 HP PA-RISC workstations running HPUX --,
and those were actually pretty nice environments.

We had a few rooms of 029s (perhaps sixty). They were clean and very
bright, if littered with cards and chad. I only took one CS course
(well, I started a PDP-8 assembly course but got sick so dropped it).

I had an Amiga 3000 at the time... and while Berkeley SPICE was available, the
guys with PCs were already running the free version of PSpice which had much
better graphing abilities.

Laptops were quite new and insanely expensive (and machines mere mortals could
afford had the crappy highly-multiplexed monochrome LCDs). How far we've
come -- today I'd wager >99% of engineering students have PCs, almost all of
those are laptops (all active-matrix LCDs now), and nearly all campuses have
ubiquitous WFi.

Sure. That stuff is all cheap now. OTOH, PCs have always been cheap
compared to tuition. Even in '82 an entry level machine was about the
same (in the same $$) as my HP45 in '73.

 

[krw]

On Thu, 18 Feb 2010 16:42:27 -0800, "Joel Koltner"
<zapwireDASHgroups@yahoo.com> wrote:

Thinking back, at the time a desktop PC still cost the equivalent of perhaps
30 college textbooks. Today, a reasonable laptop is perhaps all of 5...!

Textbooks have gotten expensive. ;-)

 

[Jim Thompson]

On Thu, 18 Feb 2010 16:42:27 -0800, "Joel Koltner"
<zapwireDASHgroups@yahoo.com> wrote:

Thinking back, at the time a desktop PC still cost the equivalent of perhaps
30 college textbooks. Today, a reasonable laptop is perhaps all of 5...!

My first 386 with a 387 co-processor cost me around $4K, and it was a
clone (~1987)

...Jim Thompson
--
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