25 Jan
1999
25 Jan
'99
10:06 a.m.
ard(a)p850ug1.demon.co.uk (Tony Duell) wrote:
What's the real difference between a 1702 and a 1702A? I must admit that
I am not a great one for historical correctness, so I tend to use
'updated' parts if I happen to have them to hand
> Dwight
-tony
Hi Tony
1702's use a different programming algorithm than the
1702A's. Otherwise they work the same. Only a few
1702 were made, making them quite rare. Most have been
melted down for the gold that Intel used in
early packaging.
I'm looking for the non-A types because I have an
old 4004 development system that has a programming
board on it. Of course, the board was designed to do
1702's and not 1702A's. It had a selector to select
another PROM type that looked like it would work but
the signal levels still were not correct. I suspect that
they intend it to work but didn't understand the changes
the chip designers were up to. It does part of the needed
changes but not all.
Thanks
Dwight