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From: darrylo@hpnmdla.HP.COM (Darryl Okahata)
Newsgroups: comp.sys.handhelds
Subject: Re: **** SPICE FOR HP28S or 48SX By Grapevine Pub.??? ****
Message-ID: <1570008@hpnmdla.HP.COM>
Date: 13 Sep 90 16:39:48 GMT
References: <1990Sep13.000321.10513@ux1.cso.uiuc.edu>
Organization: HP Network Measurements Div, Santa Rosa, CA
Lines: 42

In comp.sys.handhelds, gcw20877@uxa.cso.uiuc.edu (George Wang) writes:

> I recently found out that some sort of SPICE circuit analysis
> program exists for the HP28s.. It's a book called Software
> Power Tools made by Grapevine Publications and can be brought
> from Educalc or Grapevine direct...
> 
> My first question is... SPICE for a HP28S with 32K RAM??
> Is that possible?? Surely it's not a full version... if not,
> how much can it actually do?? Does it handle transitors, transient
> analysis, ac analyis, diodes, etc??  Has anyone used this
> program and have any comments on it??

     I have not seen such a program, but, if one existed, I'd like to
make the following comments.

     Writing an AC or DC analysis program for *LINEAR* circuit elements
(caps, inductors, resistors, etc.) is actually quite trivial.  I imagine
that most of the work in writing such a program would be in writing a
user interface (entering circuits, displaying Bode plots, etc.), as the
"simulator" would consist of a simple routine to solve a complex matrix
(and we all know how good the 48SX is at solving matrices :-).  It would
be slow, though.  Some people would probably find the speed acceptable,
however.

     Handling nonlinear circuit elements (transistors, diodes, etc.) in
an AC or DC analysis *may* be possible, but it's not trivial.  It would
probably run very, very slow.

     Handling transient analyses may also be possible (for small
circuits only), but you would need *LOTS* of memory (128K?  256K?), and
it would probably run slower than frozen molasses in January (unless it
was written in assembly language).  You would probably be better off
watching grass grow.

     -- Darryl Okahata
	UUCP: {hplabs!, hpcea!, hpfcla!} hpnmd!darrylo
	Internet: darrylo%hpnmd@hp-sde.sde.hp.com

DISCLAIMER: this message is the author's personal opinion and does not
constitute the support, opinion or policy of Hewlett-Packard or of the
little green men that have been following him all day.