"John Larkin" wrote in message
...
RS-232 and optionally Ethernet. We wrote a flash upgrade program for
Windows. But our customers may be running Windows, RT Linux, an RTOS,
or a PLC with ladder logic. A physical eprom is easy to explain.

More seriously... perhaps a good approach would be to keep a socketed flash
ROM inside? That way people with "easy" connectivity back to your boxes could
re-flash them from firmware upgrades downloaded from your web site, whereas
there's still the option to physically replace the ROM if that's not
desirable.

Do you not have customers asking for field-upgradeability (without opening the
box)? If not I suppose this is all rather moot...