[geeks] WANTED: chip level design software for UNIX/Linux

[Charles Shannon Hendrix]

Thu, 10 May 2007 @ 08:48 +0300, Geoffrey S. Mendelson said:

> On Wed, May 09, 2007 at 08:12:15PM -0400, Charles Shannon Hendrix wrote:
> > I've been playing with more low level toys lately, so I have some
> > questions about learning small computers.  I know that Bill mentioned
> > Z80 stuff in the past and some of the rest of you, so I figure you'll
> > have some ideas at least.
> 
> I have some suggestions:
> 
> 1. Look at the following: I was looking at them for using on my MAC and for
>    analog circuts, but some have Windows or Linux versions, are free or
>    cheap for students (including self-educating ones).
> 
> 	http://www.swcp.com/~jchavez/osmond.html

Neat... I have a use of my remaining Mac IIci now.

Doesn't do simulation though.

> 	http://www.mccad.com/

Likewise.  Spice does simulation, but not of semiconductor parts.

What would be really nice is to be able to simulate a board as you
design it, 6502, chips, etc. I guess that's asking too much.

> 	http://geda.seul.org/

Thanks for the links.  Need to find a monitor for the IIci to play with
some of those.  Some of the Windows stuff might run under emulation.

> 2. Ask around in the computer experimenter and HAM community and see if there
>    is someone local who does one-off boards for experimenters. They may
>    suggest a program for you to use. 

Unfortunately, that's about dead in this area, or I'd probably not be
asking here.

> 3, Look at the Z8. It's still in use as a microcontroller, there are
>    lots of documents, projects, and programing for it. You can download
>    PDF files of all the documents, a free software development kit,
>    and last I checked buy a simple test kit for about $40.

OK.

> > First thing: I'm going back and relearning basic computer circuits. I
> > can't really afford to set up the real hardware since I've gradually
> > thinned out my parts over the last 15 years.
> 
> Things have changed, you don't need a lot of hardware. There are
> zillions of emebeded chips, development tools and systems available
> now. Microprocessors are so cheap and powerfull these days that ASIC
> (application specific IC) design is becoming a lost art.

There are two parts to what I want though: part of it is just learning
more about embedded systems, and yes, that part has changed.

However, the other part is learning the base components, with the
eventual goal (which I may never reach) of building my own computer, CPU
and all, out of base parts.

> Old chips live on in cheap low power versions. One famous ham radio

Oh sure, all over the place.

Technically the Model M keyboard I'm typing this on has an embedded CPU,
and the other day I found a website where a guy loaded his own code on
one for kicks.

I thought it was too limited to do much besides decode keystrokes, but
evidently it can do more.

> > In college we used Cadence, but that was mega expensive back then, and I
> > imagine still would be.
> 
> You should contact the company they may have a student version or
> a demo you can use. 

I suppose. It was over 1 million US dollars when our school got it in
1990.  I remeber we got some "screaming fast" Sparc 2 system to run it.

One guy designed a 32-bit CPU while getting his masters degree, and we
sent the files off to a local fab, and then sent us 5 CPUs.  They
worked.

I thought that was the coolest damned thing I'd ever seen.

I've also used computers at work where the CPU was all discrete logic,
the whole thing.  Some were amazingly fast too, with fairly high clocks.

Of course, now and then we'd hear something go "spack", and have to
search for a burned spot where a 74 series blew its mind.

It's amazing to see a complete computer, where every chip's model number
starts with 74.

> http://en.wikipedia.org/wiki/Don_Lancaster 

He's an interesting fellow.

> Again, ask. Sometimes the companies will provide you with free tech
> support, samples, etc. 

If they'd send me a trainer board, that would be great... :)

> Another thing you can do is collect broken iPods and Palm pilots.
> iPods, etc use ARM processors, Palms, 68000. Pocket PCs use ARMs too.

Base parts are not really a problem, but the boards are.

I used to college old computer parts locally and strip them.  I've used
all those parts up in the years since.

I really can't believe I used to spend that much time on it. I took a
68000 out of some kind of automotive analyzer and replaced a friend's
dead Mac CPU with it. 

Back in the 80s at local computer clubs, we used to have people bring in
their systems and repair them, often using parts from other systems.

Manufacturers sometimes used rare 74 series and other chips, and
we'd have to find the closest match and use jumper wires to make it
compatible.

One guy at the Atari club figured out how to get a hi rez graphics mode
on the Atari by a couple dozen jumpers between Antic, GTIA, and 6502,
and an extra GTIA chip.

Those were the days... :)

-- 
shannon
     \                         | And in billows of might swell the Saxons 
<===>|==Downfall of the Gael=> | before her,-- Unite, oh unite!
     /                         | Or the billows burst o'er her!