Re: [N8VEM-S100:588] Re: S-100 8086 Up and Running

[Bill Lewis <wrl...@gmail.com>]

35 years ago I left a 2716 or 2532 or something of that ilk outside
"in the sun" for a week.  Granted, this was in gloomy Upstate NY.
But it was not erased.

Question on erasing though.  Is exposure cumulative?
If you put a chip in the eraser for 1/2 the require time, and stop.
When you start again, will it require the full time, or only half?

Bill

On Mon, Dec 26, 2011 at 11:28 PM, John Monahan <mon...@vitasoft.org> wrote:

FWIW Leon, the newer high capacity EPROMS have tiny cells and so are much
more susceptible to UV exposure. The old 2716's etc. were hard to erase even
with a proper UV lamp!  Remember with erasing, you move electrons into an
isolated charged island  on a silicon insulator.  It's not an all or nothing
effect, as the charge builds up the cells with 0's  will be unreliable at
high speed reads.

John