I agree the Z-80 was the greatest microprocessor - its rich assembly langauge was a high level language in itself. It was not however a great microcontroller.

The 8051 is a strange collection of opcodes and many times it appears to be in the way of doing commmon tasks like block copies in external ram. But the more you look at it, you'll discover that it is well tailored for the microCONTROLLER job.

Its a great machine for automata applications wherein you aren't supposed to require banks of memory; monitor inputs, use a little memory and clever algorithms to create smart output. If you need an 8 bit bus... for heaven sakes use something better.

I've said before that most micro applications use too much ram. My office saying is, "If you want that much RAM you haven't thought up a good solution yet."

Opinions differ and I know that annoys many but its quite true. We've had that discussion, I'll leave it there.

One nice difference I noticed after using an 8051... I keep looking for additional schematic pages that aren't there and not required. A true mark of a good microcontroller solution - simplicity.

-Jay C. Box

PS: - - - - - -

My mentor, a great machevellian design engineer once named Tom Thalley said of his company:

(") The reason we succeeded rather than our competition is that we chose a fast bit-banger micro with only eight instructions (8x300) whereas they designed their own bit-slice processor.

Our micro gave us nothing to do but draw the signals to its pins and then start programming. Never overlook the advantage of simplicity.

The competition spent twice as long and introduced a dual-board product. A design failure. {"}

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Unknown to my mentor, I was interviewing with the competition at the time and had heard the stories of how they had wasted almost a year designing their bit-slice opcodes by committee. 8-)

Simplify...

And take what you learn to the competition for a big salary boost! heehehehe