clifto wrote:
Chuck Harris wrote:
Spice is an interpreter.

SPICE makes sense as an interpreter. Compilers are best for programs you
write once and use several times; interpreters are best for programs you
run once but write several of. If you consider every change to a circuit
to be a separate program you run once (which makes perfect sense when you
consider you would be recompiling it every time you made a change), and
you consider that once the circuit works to your liking you probably won't
be running that simulation often, then an interpreter is perfect for the
job and a compiler would be slow and inconvenient.

There is an additional, very important reason to use an interpreter:
Ease of debugging. An interpreter knows exactly what is happening in
all of the data spaces, indexes, jumps, subroutines, etc. at all times.
That factor makes it easy to debug. Interpreted languages, such as Python,
Perl, and apl have extensive debugging facilities available. Debugging with
a compiler is a much more complicated matter.

-Chuck

Chuck Harris wrote:

snip

It sure will, and just like good old DOS Orcad, you will have some people
who keep around old legacy DOS systems just so they can use it.

I would have loved having DOS Orcad; I used to use the demo version
which wouldn't save or print, by using a video printer for output.

I have rather a lot of software that was written for Windows 95,
that is no longer usable with NT, XP, or Vista. Am I supposed to
keep a '95 box around just to run it?

Why not run the old O/Ses on virtual machines? I know quite a few
folks who have a boatload of old O/S and apps running under VMWare.

Regards,

Michael

msg wrote:
Chuck Harris wrote:

snip

It sure will, and just like good old DOS Orcad, you will have some people
who keep around old legacy DOS systems just so they can use it.

You are in luck, it is available. Check out the OldDosOrcad group on Yahoo.
Even DOS OrCAD's author appears there from time-to-time.

I would have loved having DOS Orcad; I used to use the demo version
which wouldn't save or print, by using a video printer for output.

I have rather a lot of software that was written for Windows 95,
that is no longer usable with NT, XP, or Vista. Am I supposed to
keep a '95 box around just to run it?

Why not run the old O/Ses on virtual machines? I know quite a few
folks who have a boatload of old O/S and apps running under VMWare.

And I am doing just that, with linux and Wine. Wine allows me to run
a windows program as it existed on the day it was written, but does nothing
to help me if I need some changes.

-Chuck

Marra wrote:
I suspect a lot of these old and free PCB CAD packages are not taking
full advantage of the current PC hardware.


PC's have bags of memory now so the old pin limited packages are out
of date.


That is certain to be true.

Yet another argument in favor of open source.

-Chuck

I suspect a lot of these old and free PCB CAD packages are not taking
full advantage of the current PC hardware.


PC's have bags of memory now so the old pin limited packages are out
of date.

Things like vast processing power can be done to do things like auto
placing of components.

In my software I also added right click context menus which are very
user friendly.

www.murtonpikesystems.co.uk

Chuck Harris wrote:
clifto wrote:
Chuck Harris wrote:
Spice is an interpreter.

SPICE makes sense as an interpreter. Compilers are best for programs you
write once and use several times; interpreters are best for programs you
run once but write several of. If you consider every change to a circuit
to be a separate program you run once (which makes perfect sense when you
consider you would be recompiling it every time you made a change), and
you consider that once the circuit works to your liking you probably won't
be running that simulation often, then an interpreter is perfect for the
job and a compiler would be slow and inconvenient.

There is an additional, very important reason to use an interpreter:
Ease of debugging. An interpreter knows exactly what is happening in
all of the data spaces, indexes, jumps, subroutines, etc. at all times.
That factor makes it easy to debug. Interpreted languages, such as Python,
Perl, and apl have extensive debugging facilities available. Debugging with
a compiler is a much more complicated matter.

You're right. In a way that's what one is doing when changing a SPICE
simulation repeatedly while testing/modifying a circuit.

--
A staffer for Democrat Senator Maria Cantwell of Washington has been
arrested for trying to arrange a sexual tryst with a 13-year old boy.
http://www.thesmokinggun.com/archive...72senate1.html

"Marra" wrote in message
...
I suspect a lot of these old and free PCB CAD packages are not taking
full advantage of the current PC hardware.

Possibly true, although I can comment that "PCB Artist" which is the free PCB
package Advanced Circuits has wouldn't fall into that category: It's really a
version of EasyPC (from Number One Systems / WestDev) in disguise, and quite
sophisticated.

PC's have bags of memory now so the old pin limited packages are out
of date.

Pin limiting has, in the past decade or so, always been a means of
artificially restricting users based on how much they were willing to pay for
a license and has nothing to do with not taking advantage of the hardware.

Things like vast processing power can be done to do things like auto
placing of components.

I've yet to see an auto-placer that's worth using, but I'd admit that I
haven't used yours.

In my software I also added right click context menus which are very
user friendly.

Most Windows software did this around 1995-2000...

(Of course, there's still overpriced stuff like PADS out there that TO THIS
VERY DAY cannot be installed in a directory that has a space in its names...
like, oh, say, c:\program files...)

---Joel

PC's have bags of memory now so the old pin limited packages are out
of date.

Some of the free packages are based around DOS or early windows where
a megabyte of memory was the limiting factor.

Anyone who has put the effort into writing a "full" PCB software
package is not going to give it away.
It just doesnt make sense, they would be better off pulling pints at
the local pub to make money.
The pin limitation was used to offer cheaper packages to people but
even some of the larger packages I have seen have limitations on them.
I think my software tops out at 32000 pins per package which is an IC
I am eager to see !
In fact you run out of room on the 50 inches by 50 inches layour
before you run out of memory !

Marra wrote:
Anyone who has put the effort into writing
a "full" PCB software package is not going to give it away.

You are so full of ****.
http://www.google.com/search?q=gEDA+free
http://www.google.com/search?q=KiCAD+free

"Marra" wrote in message
...
Anyone who has put the effort into writing a "full" PCB software
package is not going to give it away.

This is true, but from an *end user* perspective something like what
ExpressPCB and Advanced Circuits does might as well be the next best thing to
free: They create or license reasonably full PCB software (especially in the
case of Advanced Circuits) and presumably pay for it off of profits made from
fabricating the boards... which ends up being much cheaper (really, probably
no more than a few dollars per design) for a hobbyist who isn't cranking out
dozens of PCB designs every year and doesn't have particularly high-end
requirements.