sourcing Atmel 29Cxxx series flash roms

[allison]

On 3/13/17 12:39 PM, Jon Elson via cctalk wrote:
> On 03/13/2017 02:23 AM, David Griffith via cctalk wrote:
>>
>> I'm almost out of Atmel 29C256 flash roms.  I use these primarily for 
>> P112 boot roms.  I'd like some more because I still have P112 boards 
>> to sell... and I want them for other projects.  Mouser, Digikey, and 
>> Jameco don't have it anymore. What are you guys doing to get these 
>> and equivalent chips?
>>
>>
> I have some 27C256, don't know if those are compatible. Alltronics in 
> San Jose (or thereabouts) used to have a massive stock of older chips.
>
> Jon
>
>
FYI:

27Cxxx is an EPprom
28Cxxx is an EEprom
29Cxxx is a  flash prom

Then can be pin compatible in SOME system but they program very differently.
IT the system expects to be able to rewrite some locatons then you need 
EEPROM.
If the system expects to be able to rewrite blocks then it s flash.
If you put a Eprom in you can do none of those things without a UVlamp 
and an external programmer(most cases).

The P112 can use all or any save for being in system writable if needed.

Allison