--- Sellam Ismail <foo_at_siconic.com> wrote:
> On Tue, 15 May 2001, Hans Franke wrote:
>
> > When where the first 74xx ICs released / designed ?
First? Don't know. As has been mentioned, the M series of FLIP-CHIPs
from DEC used TTL (7400, 7404, 7474, etc.) Mine have date codes in the
range of 1968-1969. I don't recall if there are any in my machines with
codes prior to 1968. I would have to look.
> > Especialy when where complex chips like 744x, 748x or
> > 74181 first mentioned/available ?
No idea. If I had to guess, I'd say 1970.
> > ... so all I have is my personal guess (~1970)
Ah! Good guess.
> > Anyone more informed ?
>
> I think you guys are going to have to use DTL. If TTL was even around in
> 1970, it was probably pretty expensive at first.
>From http://www.faqs.org/faqs/dec-faq/pdp8-models/
Subject: What is a PDP-8/L?
Date of introduction: 1968 (Announced before August '68)
Date of withdrawal: 1971.
Total production run: 3902.
Price: $8,500
... and...
Subject: What is a PDP-8/I?
Date of introduction: 1968 (Announced before December '67)
Date of withdrawal: 1971.
Total production run: 3698.
Technology: DEC M-series logic modules, called M-series flip-chips
as the term flip-chip was applied to the module format instead
of to DEC's hybrid integrated circuits. M-series modules used
TTL chips, with a +5 volt supply, packaged on the same board
format used with the original flip-chips, but with double-sided
card-edge connectors (36 contacts instead of 18). Modules were
limited to typically 4 SSI ICs each. The M113, a typical
M-series module, had 10 2-input nand gates and cost $23 in 1967
(the price fell to $18 in 1970). Wire-wrapped backplanes used
30-gauge wire.
So here is evidence that in 1967, DEC was shipping modules with TTL parts
on them, and that the cost was probably a small number of dollars per part,
certainly less than $10/chip for some of the simpler ones. The M113 has
three 7400 chips on it, does it not? Based on the price of $23, I'd expect
that the IC were a few dollars each and the rest of the price was for
the PCB and assembly, testing, storage, shipping, profit, etc.
Does $2-$3 each count as expensive?
-ethan
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Received on Tue May 15 2001 - 12:09:56 BST