replace an EPROM with an EEPROM?

[David A. Cooley]

Where'd you find a 28 pin 28C256?
They are 32 pin devices. The 28C64 and 28C128 are 28 pin like the 27C64.

At 07:28 PM 1/31/99 -0600, you wrote:
>I used a 28C256 ( 28 pin 32Kx8 EEPROM chip) in place of a 2764 in an ECM.  I 
>was
>lucky as the board had the unused pins of the 2764 pulled high ( /WE and the
>highest 1 or 2 address lines of the 28C256.) I believe the only odd thing
I did
>was to load the program at 2 differant offsets to get it right.  This worked 
>fine
>once the offset was correct.  You shouldn't have to play with offsets if you 
>are
>using the same size of chips.  Just get the pinout correct when making the
>adapter.
>
>I did put ZIF sockets into this ECM as the original chips were soldered
in.  No
>more bending of leads.

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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
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       I am Pentium of Borg...division is futile...you will be approximated.
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