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Embedded Muse 37 Copyright 1999 TGG September 13, 1999

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EDITOR: Jack Ganssle,

- Embedded Seminars in Chicago and Boston
- Book Review
- Write Only Memory
- Thought for the Week
- About The Embedded Muse

Embedded Seminars in Chicago and Boston

I’ll present the seminar "The Best Ideas for Developing Better Firmware Faster” in Chicago and Boston on November 8 and 9, 1999.

The focus is uniquely on embedded systems. I'll talk about ways to link the hardware and software, to identify and stamp out bugs, to manage risk, and to meet impossible deadlines. If you’re interested reserve early as these seminars fill completely.

For more information check out or email

A lot of folks have asked me to bring this seminar to their company. Email me at if you’re interested.

Book Review

An excellent new book, “An Embedded Software Primer”, by David E. Simon (1999, Addison, Wesley, ISBN 0-201-61653-X) came across my desk this month. Embedded titles are becoming more common – not so long ago ANYTHING embedded was worthy of attention – but this book is a standout.

It’s aimed at the novice or nearly novice embedded person, one with experience in C but little feel for the unique issues of embedded systems. The book starts with the standard introduction to microprocessor hardware (which could have been left out), but quickly moves on to a very good description of interrupts; this section alone is quite worthwhile.

Three of the 11 chapters are devoted to real time operating systems. The included CD has a copy of the older version of Jean LaBrosse’s uC/OS RTOS. Whether you use uC/OS or a commercial product, Mr. Simon’s discussion of RTOS issues is a very good introduction to the subject.

If you’ve never used an RTOS, this is a pretty good reference (but also check out MicroC/OS-II, LaBrosse’s new companion volume to his upgraded RTOS). If you’re trying to figure out what firmware is all about, and get a sense of how one should write code, this book is for you.

Write Only Memory
Many years ago Signetics issued a data sheet for their “write only memory” (think about it!), a device appropriately introduced on April fools’ day. It’s an amazing part, which requires the normal 5 volt power as well as 6.3 volts AC (for the filaments), and whose reliability is shown as a function of what customers pay for it.

Years ago I had the datasheet posted on another web site. Quite a few folks have written and asked for a link to that site, which is now defunct. So it’s now back on-line, at http:\\ Follow the link under “Articles About Embedded Systems”.

Thought for the Week


All those backups seemed a waste of pay.
Now my database has gone away.
Oh I believe in yesterday.

There's not half the files there used to be,
And there's a milestone
hanging over me
The system crashed so suddenly.

I pushed something wrong
What it was I could not say.

Now all my data's gone
and I long for yesterday-ay-ay-ay.

The need for back-ups seemed so far away.
I knew my data was all here to stay,
Now I believe in yesterday.