[Coco] EEPROM replacement for 27C256

Dave Philipsen dave at davebiz.com
Sun Jun 28 00:17:40 EDT 2015


There is a 28C256 that is as probably as close as you'll get in terms of 
pinout.  It won't be an exact drop-in replacement, though, as the A14 
pin changes position and you'll have to come up with a write enable as, 
obviously, the 27C256 which is a primarily read-only device does not 
have.  I have a 28C256 floating around here somewhere that I used in a 
custom circuit I built one time but I've never tried to wire it up to a 
CoCo3.  One thing for sure, you'd have to make sure that any changes 
written to the EEPROM contain no undesirable code that could cause the 
CoCo to become unbootable.  Otherwise you'd have to pull the 28C256 and 
re-program it out of circuit.

Dave Philipsen

On 6/25/2015 2:43 PM, John B wrote:
> Does anyone know of a suitable EEPROM replacement for the 27C256 found in
> the CoCo3?
>



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