>I've got 8 chips exhibiting this behaviour, and I tried erasing for 20 min.
>without success.  I'm using relatively old chips, I believe, but even with
>the code protection, would 20 min. be reasonable?

If they aren't "A" suffix parts, should be fine.  Try a longer exposure, or
a new bulb.  How quickly do other chips erase for you?

Andy


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Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
          Hardware & Software for Industry & R/C Hobbies
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