4004 and IC history / was Re: Vintage computer photogallery

Brent Hilpert hilpert at cs.ubc.ca
Sat Oct 13 01:02:14 CDT 2007

dwight elvey wrote:
>  Core was an important step in computing. Much more than Intel's
> 4004.
>  The microprocessor was happening with or without Intel. Intel's
> most significant achievements were the EPROM and solid state memory.
> The only other thing I consider even more important was the quartz
> crystal used for timing, as an achievement. I'm not sure who to
> credit for that one.
>  I shouldn't leave out TI's creation of the IC in the first place. ALthough
> I have a 4004 development system, the 4004 was a minor step compared
> to the others.

(No doubt that core was important, just the way it was attributed in the photo
blurb was misleading).

I quite agree about the 4004. It may have been first, but it was one of those
things whose time had come - it really wasn't that big a conceptual leap. Some
time ago I ran across an editorial in a magazine ca. 1969 that basically
summed up the problem: increasing logic density and hence IC complexity (LSI
was on the horizon) would result in an explosion of chip designs that would be
unmanageable (unique design per task,low production runs,etc.). The answer a year
or two later would be the microproc (few chip designs, uniqueness in software
in ROM). You could say FPGA/CPLDs are another, more recent, answer to that
question. Now if only I could find that editorial.

Based on what I've read though, I disagree about the (degree of) credit generally
given to TI/Kilby regarding the creation of the IC, on similar grounds: in the
late 50s there were lots of efforts/attempts/designs to create miniature
modules of some sort. Kilby made the 'obvious' (like the microproc)
development of not cutting the transistor dies apart from the wafer before
interconnecting them and got to the patent office first on that issue. His
techniques however, were frankly a bit of a hack that weren't going to go
(scale up) anywhere.
It was the development of the planar form of transistor by Hoerni, junction
isolation by Lehovec and putting it all together with various layering
techniques by Noyce at Fairchild that created and made feasible the IC as we
still know it today.

Can't testify to it's accuracy but one of my favorite quips about the 4004
is the reason it had that multiplexed 4-bit bus/machine cycle was to squish
it into a 16-pin package because management didn't want to tool up for larger

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