Ken Garlington wrote:
>
> > Philip Johnson wrote:

I appologize.  Apparently I did not differentiate sufficiently between
the
two controller domains.

> > I have some embedded systems that have
> > a limited control domain (raise/lower, open/close) that is very small
> > and runs in 256 bytes of memory located on the processor.

                                  ^
                                  |
This is the square inch controller domain.  All of the code is
assembler.


> > I mostly
> > have embedded control systems that have a real-time executive in EEROM
> > that provides the OS functions with limited multitasking (8-16 tasks).
> > The RT OS calls can be implemented in the system package, etc.

                                  ^
                                  |
This is the single/multiboard [mezzenine] controller domain.  The EEPROM
is
32Kb.  This code is a mix of assembler, Pascal, and Modula-2.  I have a
prototype project that is planned as an Ada testbed.  It is about a
month away
from start but I will keep you posted on my progress.  This will be a
rewrite
of the Pascal code. The Real-Time executive is assembler.  It might be
interesting to do a rewrite of the RT exec in Ada.

>
> You can do 8-16 tasks with 256 bytes (not Kbytes, but bytes) of RAM,
> and still leave the user space for a stack and a heap?

I only wish that I was that good.  8^{)

> How big are your TCBs? How much space do you allocate for each entry? Could
> you post the source for the system packages you used to implement this?

I will post anything I can get a company OK from.

Phil
--
 _______________________________________________________________________
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|                Ada, Perl, and Java! It can't get any better.
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|Philip Johnson                             Telco: (205) 890-1178
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|Sr. Software Engineer                      Fax  : (205) 890-1174
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|International Space Systems Inc.           email: [log in to unmask]
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|Huntsville, AL
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