Replacing a 27C256 with a 28C256

[Tedscj at aol.com]

Hi,
Does anyone know if it is possible to replace the 27C256 Eprom with a 28C256
EEprom on a Memcal for a 7730 ECM?
The reason I'm asking is that I can get a EEPROM programmer for $49 rather
than a EPROM programmer for $150 to $200 PLUS $50 for the UV eraser.

Here is something I got off the net on the subject:
The most important pin we must consider is pin 27. On the 2764, pin 27 is the
'program' pin. On the 2864 pin 27 is the 'write' pin. If pin 27 on the 2764 is
low, the system cannot read the program data in the 2764 and for this reason
pin 27 is usually wired directly to pin 28 (+5 volts). As long as pin 27 is hi
when pin 28 is hi, a 2864 should reliably replace a 2764. If pin 27 is allowed
to go low when pin 28 is hi. It is possible a 'write' could occur in the 2864
corrupting the data. In most systems, pin 27 is wired directly to pin 28 or
thru a resistor to pin 28.

I don't know what impact this would have on the Memcal.  I basically don't
know much of anything on this subject.
I am just looking for a more economical way to start exploring and playing
with the calibrations in my 730 ECM.

Thanks,
Ted