8 Aug
2008
8 Aug
'08
6:58 p.m.
On Friday 08 August 2008 21:44, Eric Smith wrote:
Roy J. Tellason wrote:
My first TTL databook was from TI, and I believe there was some small number
of 24-pin devices in there, like the 74154 and similar. (Hope I'm
remembering right here. :-)
The other thing that I took some notice of was
mention of an 18-pin chip
package as "recently developed" at one point in the story, and later on
the mention of the 40-pin package as being then available.
The 18 pin-per-package limit claims regarding the 4004 and 8008 have
been around for a long time, and I think they came from interviews with
Intel's founders and/or early employees, but I think they're factually
incorrect, at least as commonly stated.
The 24-pin DIP was very well established by 1968, and was already used
by TI at that time. There were certainly higher pin-count packages at that
time also. I'm not
sure about the 40-pin DIP, but in 1969 Fairchild was shipping at least one
memory chip in a 36-pin DIP, though that particular package never became
popular.
There were also those "flatpacks" which I never could figure out. A precursor
to surface mount? Something else?
Possibly whatever specific company Intel was
contracting with to supply
lead frames and ceramic packages didn't yet offer higher pin count
packages, but they obviously were available from some vendors since
other semiconductor companies like Fairchild and TI were using them.
I guess a large part of it was the machinery to handle that stuff too,
besides the lead frames themselves. I don't know much about that stuff so I
don't know if any given production machinery would be adaptable to many
different sizes or if you'd need a different bigger machine to handle them.
If the latter was the case then I can see where they might be reluctant if
there weren't a lot of demand.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin