RadioBanter - View Single Post - "MARTHA" RF/Microwave CAD Using APL -- Free!

AF6AY

From: (Doug White) on Sun, Dec 2 2007 6:22 pm

MARTHA is NOT for everyone. It doesn't have fancy schematic capture or
PCB layout features. It also requires learning at least a little about
the APL computer language (which could be considered a worthwhile
exercise in its own right). There is no canned installation routine that
will magically get it all up & running on your computer, but there are
procedures & batch files to try to make it as painless as possible.

That's interesting that the 35-year-old A Programming Language (APL)
is still around somewhere. I learned of it way back when in '72 while
employed by RCA Corporation...and getting interested in programming
after a very satisfactory and productive introduction to 'LECAP,'
RCA's
frequency-domain version of the original ECAP from IBM.

However, today's desktop PCs have MORE speed, mass memory, RAM storage
than any mainframe computer of 35 years ago at less than $1K US new
off-the-shelf (today's Fry's Electronics ad had a PC with LCD monitor
for $400). We don't really need Interpreter-based high-level
languages now. My circa-1979 Apple ][+ needed those to work with its
fantastic clock rate of a whole MegaHertz and 48 KBytes of RAM! My 4-
year-old PC box with 1 GHz clock rate, 100 MHz RAM access rate, 2 MB
RAM, and small 40 GB hard disk can handle 50-node SPICE circuits with
perhaps 2000 time increments in a couple of seconds...and store the
results in a file. shrug

Three decades ago the UC Berkeley group came up with SPICE and made
the core of that program FREE, no restrictions (source code available
for the cost of paper reproduction and mailing). SPICE derivatives
are the electronics industry standard today. Linear Technology
Corporation has a working, auto-installable, schematic capture
enhanced (or manual netlist entry for die-hards) absolutely FREE.
"LTSpice" available at Linear Technology's website as a single
download. Many commonly-used semiconductor component models are
available as part of that. A tube-oriented audiophile website in the
UK even has several vacuum tube SPICE models (they call tubes 'valves'
- :-) for LTSpice.

As a long-time homebrewer and electronics experimenter (since 1947),
a knowledge of programming languages is not a priority to homebrewing;
that is a separate subject, interesting in itself, but not germane. A
full-blown, working, easier-to-use SPICE derivative that if FREE is
more suited (I think) to homebrewers. I've used LTSpice myself,
compared its calculations to actual, working hardware and find NO
discrepancies.

SPICE derivative programs all allow netlist descriptions of component
characteristics in algebraic form plus a shorthand that is common to
all SPICE forms for special Models. There is no need to learn FORTRAN
(SPICE core's original language) or versions written in C++ (which are
available now), or any other high-level language. For my programming
needs today, Assembler-level source code for PIC or ATMEL
microcontrollers is more germane to homebrewing. Some of those are
also FREE.

At least two PCB fabrication companies have FREE PCB layout
programs available without ordering any boards. Transferring a
schematic from LTSpice to theirs is just a schemtic redrawing
task, usually a one-shot task.

I don't mean to diminish any importance of programming languages
or any different CADs or CAEs, but, let's face it, APL is an old
high-level language. I still have the 100 W American Beauty soldering
iron I got in 1948 but it is out-of-date for soldering parts on a PCB
now.

73, Len AF6AY