On Wed, 13 Aug 1997, Andy Kunz wrote:

> >I have a dozen 'c54 chips that won't erase. I'm thinking I probably fried
> >them with too much current...
>
> Probably.  '54 usually is a couple minutes, even when cp'd
>
> Andy

Couple minutes?? Wow. I find they need at least 20. I wonder if it's
possible to damage them by UV exposure, or  by just leaving them
under normal flourscent lighting.. I usually don't cover the window when
testing.

-Shane.