Fast 27c128's a problem for Pocket Pro?

[Craig Moates]

Regarding my difficulty with the Cypress Semiconductor CY27C128-70ns, indeed
it is a 70ns, and it defaults to all zeroes instead of ones upon erasure.
Cypress is reportedly different than other EPROMS in this respect. The folks
at Intronics (George) have a workaround though, under 'E' menu in their
programming app, which allows programming of the CY devices. Problem solved.

-Craig

-----Original Message-----
From: Shannen Durphey <shannen at grolen.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Monday, November 22, 1999 10:01 PM
Subject: Re: Fast 27c128's a problem for Pocket Pro?


>Craig Moates wrote:
>>
>> Folks,
>>
>> Against better advice, I purchased a pocket programmer. It works fine so
far with some 150ns 27c128's I used. I purchased some 120ns chips of the
same type, and received what appears to be 70ns. They are by Cypress
Semiconductor. Anyhow, they don't check out on a blank-check, even after
erasure for over 1 hour. The 150ns variety (different mfr. - AM..). The zero
check yields 'found 00, looking for FF'. The program verify also does not
check out. Haven't tried to see if programmed chips work yet. Anyone else
see this? Suggestions, other than 'we told you so..'? What, do I need slower
chips?
>>
>BTW, the 27128 is the only chip I've had problems with.  All the
>problems went away after switching programs.
>HTH.
>Shannen
>> Thanks,
>> -Craig
>>
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