The difference is, that the RD2/ED2 chips are in fact descendants of the Temic line of '51s (Atmel bought Temic several years ago), so it is a different core.

I still wouldn't call this a flaw, the chip does exactly what it is supposed to do: /EA low means external execution, lockbit means no external fetches - for me it means this combination is beyond the specifications, so its behaviour is undetermined as per datasheet.

But you can of course go and try out all the Philips, SST and Winbond RD2s and see, which will satisfy you - but be warned, if it is not in the datasheet, or you don't get it approved by the manufacturer in some way, it is simply not guaranteed to work, and may not work e.g. under marginal conditions.

Jan Waclawek

PS: what's wrong in tying that $&@# /EA pin to VCC???