Well, if you are *really* concerned about radiation, you might inquire
within microchip to make a few mask rommed parts.  These are parts where
the code is part of the silicon when the chip is made.

But they might not have the ability (or desire) to make just a few for
you...

-Adam

Lea wrote:
>
>         Hi, all.
> I'm on a proyect to build a small and very dumb controller to drive a stepper
> motor, the program just start when one pin go to low state and move the
> motor at about 80pps for 10 seconds, that part is O.k. works fine,
> but It must work fine at the space for about a week, shuttle nominal
> altitude, so the question is: which kind of device to do this is better:
> EEPROM, EPROM or FLASH??.
>
> I know that radiation and high enery particles erases most memories but
> if the enclosure is good they will need more than a month, may be more to
> erase at least 1 bit (I'm talking about EPROM) but I have no idea about
> the other kind of memories EEPROM and FLASH.
> have someone an idea which will be the difference in this enviroment?
> I need to make a decision about the pic to use for that app.
> thanks!.
>    Leandro J. Laporta (LU2AOQ)
>    mail: lu2aoq@yahoo.com
>    wrk: Arg. Assoc. for Space Technology.
>    ham: TCP/IP high speed group HSG