Intersil EPROM

Allison ajp166 at
Tue Jun 16 10:52:17 CDT 2009

Ethan Dicks wrote:
> On Tue, Jun 16, 2009 at 3:42 AM,
> Scanning<steven.alan.canning at> wrote:
>> Chuck,
>> You are correct sir. I had forgotten about the dark ages of 4000 Series 10
>> Volt Bulk CMOS. It's all coming back to me now, the night sweats and the
>> flashbacks....  I think I even have a 10 Volt CDP1802 lurking in a drawer
>> somewhere...
> I have one 1802D in a ceramic package.  ISTR it will push to 10V
> (which is required to take it much above 1MHz).

That is in error.   The 1802D early versions ran to 3.2mhz accoring to 
the data sheet
at 5V.  In practice it was more like 3mhz.   I have an elf built back 
when using the 1802D
running at 2mhz which was the commonly used frequency.  It still works!

>> I've been looking for another 10 Volt CMOS EPROM without any luck. Looks
>> like building a programmer for the parts he has might be the best approach.
>> If we knew the source for the EPROM data we might be able to kludge up a
>> Willem ( sp? ) programmer to program a part....
> You don't have to program a CMOS EPROM at 10V Vcc to use it at 10V
> Vcc.  It's not 10V *only*, it should take any voltage in a wide range
> (the exact min and max Vcc depends on exactly what family the part is
> from, but 3V-15V is common).
> Why wouldn't a 27C64 work?  (admittedly, I don't have the data sheet
> in front of me).  You'd have to make a pin swabber for the destination
> machine, but electrically, it's a "C" part, not an "HCT", so I'd
> expect it to work at 10V, but the datasheet will say for sure.
> -ethan

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