On Jun 4, 14:14, Joe R. wrote:
> Dwight,
>
> I have a programmer that's suppsoed to be for the intel 2704 and
2708.
> I've never seen any info on the 2704 and I've never seen one but I'm
> guessing that it's a half bad 2708. Do you know any more about it?
Maybe. If so it must have been identified before the leads were added,
because the Intel Data Catalogue 1976 lists both 2704 and 2708 on the
same page, and the only difference is pin 22. On a 2708, that's A9, on
a 2704 it's always 0V (always 0V, cf 2716/2758 below). No pictures,
unfortunately, so no immediate way to tell if the dies look the same.
Interestingly, the 1976 book doesn't list anything bigger than a 2708.
So a 2708 obviously wasn't a half-bad 2716 (at least, Intel ones
weren't).
The 1979 Data Catalogue lists the 2704 only as a footnote to the 2708
description, and the 2716 appears only as a single-rail version. I
thought they did both, but I must have been thinking of another
manufacturer.
The 1979 book lists 2716, 2732, and 2578. The 2758 has exactly the
same power consumption, access times, programming, and pinout as the
2716, except that pin 19 is A10 on a 2716 and is AR on a 2758. AR is
"select reference input voltage". The tables show this as always Vil
(ie, 0V) but in one place only, the small print says that it's always
0V *except* for devices labelled "2758 S1865", when it needs to be Vih
(+5V). Hmm, that sounds exactly like Dwight's description of a half
bad chip to me :-)
--
Pete Peter Turnbull
Network Manager
University of York
Received on Fri Jun 04 2004 - 16:24:31 BST