Old 486 Board for ECU??

TK terryk at foothill.net
Tue May 2 04:21:28 GMT 2000


I agree with you Ludis. It seems to me that you would need to take over NMI
to guarantee a consistent timing loop. Well, there goes RAM refresh. If the
BIOS was re-written to do a CAS only refresh, the problem might be solved.
The problem to me is that you couldn't have a large RAM space. When we add
the IO servicing into the problem, gulp.

Might as well start with a new design with ROM code and the tiniest of RAM
to avoid being interrupted for RAM refresh all of the time.

The PC design is not a good solutions IMHO.

At the same time, if the crank/dist triggered NMI and that routine serviced
the fuel and spark first and then timers triggered to service the
TPS/MASS/MAP/temp sensors and outputs the IAC/fans/etc, it might work. Have
the NMI at ring 0 and each timing loop outside that in doubling sizes. You'd
be counting clock cycles very close.

It would still require a new BIOS and hardware changes.

Or maybe it won't work ................

Terry



----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list