PC's and EFI

Thu Mar 19 05:38:25 GMT 1998

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I'd just like to second the notion of using "a little external
hardware - very stupid" with a PC system.

My own favorite thing is to get a   JDR Microdevices  PC wire
wrap card (with bus buffering and address decoding) and add my
external hardware on that. It is very little work to add things
like A/D, pwm, shift registers, and such.

If a slave microprocessor is necessary, I use an 8742, because it
already has a compatable bus interface and interrupt line built
in (use a pseudoSAM assembler - public domain - JDR's FTP site
has it- and resist doing anything that doesn't sound easy, even
in assembler). Any program spends 90% of the time in 10% of the
code. Figure out which 10% and put it in the coprocessor.

I have done things that make the processor workload associated
with EFI  look easy, using this method. Think about what is going
on in your video card for example, then think about what would
have happened if they had tried to do that in software, using the
main CPU, and you will have to agree that it's a powerful
technique, and the JDR card makes it easy.

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<HTML>
I'd just like to second the notion of using "a little external hardware
- very stupid" with a PC system.

<P>My own favorite thing is to get a&nbsp;&nbsp; <A HREF="www.jdr.com">JDR
Microdevices</A>&nbsp; PC wire wrap card (with bus buffering and address
decoding) and add my external hardware on that. It is very little work
to add things like A/D, pwm, shift registers, and such.

<P>If a slave microprocessor is necessary, I use an 8742, because it already
has a compatable bus interface and interrupt line built in (use a pseudoSAM
assembler - public domain - JDR's FTP site has it- and resist doing anything
that doesn't sound easy, even in assembler). Any program spends 90% of
the time in 10% of the code. Figure out which 10% and put it in the coprocessor.

<P>I have done things that make the processor workload associated with
EFI&nbsp; look easy, using this method. Think about what is going on in
your video card for example, then think about what would have happened
if they had tried to do that in software, using the main CPU, and you will
have to agree that it's a powerful technique, and the JDR card makes it
easy.</HTML>

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