There is no date defined for the creation of the first
computer chip (also known as an integrated circuit (IC),
and microchip), since it was an ongoing process for two
men from 1958 to 1959. They applied for and received
patents separately in the same year, 1959.
About.com has an excellent article detailing the work
of these two men:
"Jack Kilby, an engineer with a background in ceramic-based
silk screen circuit boards and transistor-based hearing
aids, started working for Texas Instruments in 1958. A
year earlier, research engineer Robert Noyce had
co-founded the Fairchild Semiconductor Corporation.
From 1958 to 1959, both electrical engineers were working
on an answer to the same dilemma: how to make more of
"The monolithic (formed from a single crystal) integrated
circuit placed the previously separated transistors,
resistors, capacitors and all the connecting wiring onto
a single crystal (or 'chip') made of semiconductor
material. Kilby used germanium and Noyce used silicon
for the semiconductor material."
"The original IC had only one transistor, three resistors
and one capacitor and was the size of an adult's pinkie
finger. Today an IC smaller than a penny can hold 125
Much more on the page:
Another useful page from About.com has links to more
articles about the two men:
Here's a biography of Jack Kilby from the Inventor of the
Week archives at MIT:
Here's a biography of Robert Noyce from InventNow's
Hall of Fame:
Jack Kilby applied for a patent on February 6, 1959,
which was granted on June 23, 1964, as seen on page 1
of the original papers, and shown in the images on
the following page at the US Patent Office:
Robert Noyce applied for his patent on July 30, 1959,
which was granted on April 25, 1961, as seen on page 1
of the original papers, shown in the images on the
following page at the US Patent Office site:
The next step in the process was the invention of the
microprocessor, or Central Processing Unit (CPU).
Here's a biography of the man who invented the CPU,
or microprocessor, in 1969 - Marcian E. (Ted) Hoff:
From the very extensive History of Microprocessors
on the Plymouth State College website:
"Together with Federico Fagin, later the founder of
Zilog, Hoff came up with a four-chip design; a ROM
for custom application programs, a RAM for
processing data, an I/O device, and an unnamed
4-bit central processing unit which would become
known as a 'microprocessor.'"
*Much* more on the page:
As for the evolution of the technology, I was an
electronics technician in the US Navy, so I got to
watch it happening, and use the technology as it
evolved. There weren't really major 'jumps', but
more of a smooth transition between similar
technologies which used different, and increasingly
smaller, materials. Actual circuit design has
continued to revolve around the same basic
principles which have always been used. What
has changed is the materials and engineering
involved in designing and fabricating them.
The biggest 'jump' was from the original form of
the computer, which was an electro-mechanical device
which used punchcards to store data, to a true
electronic computer, which also used punchcards.
A good place to start exploring the history of
computers is Paul Shaffer's website at Penn
Engineering. On this page, he talks about the
punchcard precursors to computers:
Eniac was the first true computer, using punchcards
in conjuction with magnetic recording tape, tubes,
resistors and capacitors.
Some predecessors to Eniac are mentioned here, on
John Mauchly proposed the Eniac to the US Army as
a solution to trajectory problems:
J. Presper Eckert worked with Mauchly on development
Here's a picture of what remains of Eniac, at the
online Eniac museum at the University of Pennsylvania
School of Engineering:
The original was announced February 14th, 1946, and
filled a very large room, as seen in this image from
Mike Muuss' website, on The U. S. Army Research
Laboratory (ARL) website, has the full story of Eniac,
written by By Martin H. Weik:
A fascinating image is the 'family tree' of digital
computing, with Eniac at the foundation:
Following that 'jump' the rest was just a matter of
the ongoing miniaturization of the components involved.
This occurred simultaneously throughout the field of
electronics. Quite simply, transistors replaced tubes,
performing the identical function but taking less space
an using less electricity. The IC chip then replaced
transistors and other components of the circuit, such
as diodes, capacitors, and resistors.
The nature of the circuit designs themselves have not
radically changed. So when transistors were invented,
a radio which fit in your hand was the talk of the
day. Though the circuit design was little different
than that of the tube radio on your bedside table,
everyone could sense that this decrease in size meant
that very big (or small) things were not far off. The
IC chip meant another dramatic decrease in size, so
now you can get a radio that fits inside the earphones
you use to listen, or in a pen. Nonetheless, the circuit
design for the radio itself is not radically different.
The trend continues, of course, with increasingly small
designs. See this page on Nanocomputing and Nanoprocessors
at the Setiai site:
Please do not rate this answer until you are satisfied that
the answer cannot be improved upon by way of a dialog
established through the "Request for Clarification" process.
A user's guide on this topic is on skermit-ga's site, here:
Additional information may be found from further exploration
of the links provided above, as well as those resulting from
the Google searches, outlined below.
Searches done, via Google:
"first computer chip"
"first computer chip" 1959
"Jack Kilby" "Robert Noyce"
Clarification of Answer by
08 May 2004 18:04 PDT
"I do know there was mathmatical formulea to figure out which tube
or resistor, or whatever, was needed in the computer or any other
electrical device. I am imagining that sequence of events, with it's
mathmatical formulea against a chip which I still don't understand how
the jump was made. And what is their mathmatical formulea that goes
to the chip for stepping up and down the power. Or is the step up or
down even needed."
I am not personally familiar with any formulae which might be used
to determine which tube should be used in a particular circuit, and
I have not located any references to this in searches subsequent to
your Request for Clarification. Had the original question mentioned
such formulae, I would not have taken the question.
The kinds of considerations and calculations with which I am familiar
with regard to circuit design are referenced on Gabe Velez' website
on the page where he discusses designing and building a single tube
"A few of the first things we want to understand and consider when
desinging a tube amplifier are the maximum plate voltage, the
cathode current, the cut off, and the power dissipation."
"To begin with, let's pick a tube to build our amp. Let's use the
ever popular 12AX7 high mu twin triode tube."
"So we look up the above parameters and the RCA tube manual
says 1 watt dissipation, 500 volts plate voltage, -50 volts
grid voltage, and 8 milliamps current. Remember, these are
maximums. There is no way that this tube can work for long
with 500 volts and 8 milliamps, because this would put 4
watts on the plate (voltage times current equals power).
Meltdown followed by implosion might be the result (that
is, the glass will squeeze itself from the pressure of the
atmosphere, having a vacuum within, while the glass itself
is soft because of the excessive heat of the plate). I have
seldom seen an amplifier desinged to have a -50 volts at
the grid. It is usually for class C or high power audio or
radio transmitter tubes."
"These amounts are maximums for each parameter individually,
not all at once. So to consider the tube's power rating of
1 watt, we would want to do something like use 300 volts
for the power supply, where the plate actually gets a
constant voltage of about 145 volts. Then take that 145
volts and figure out the current level to keep the tube
idling at about half of its power level, or 0.5 watts.
So we use the power equation P=IE (Power equals Current
times Voltage, as represented by the I and E respectively)
and juggle it aroung a bit to solve for X, which is the
current we want. So I=P/E or I=0.5/145 or 3.4 milliamps.
This is actualy kind of high for a current rating, but
according to some charts, we can get a low distortion
and noise rating with this current level. Personally,
I would use no more than 2 milliamps because I want to
have some longevity from the tube."
Much more on the page:
As you can see from the above, and the full discussion
on the page, tube circuit design simply depends on first
knowing the voltage and current specifications for the
component you plan to use, using an appropriate power
supply, and selecting capacitors and resistors which
will provide the correct voltages and currents to the
anode, cathode and plate of the tube.
When transistors started to be used instead of tubes,
the primary difference was that the power supply could
be reduced from 300 volts to 9-12 volts. Circuit design
still revolved around knowing what voltages were needed
at the collector, emitter and base of the transistor,
and selecting the resistors and capacitors needed to
produce these voltages, using the same formulae (P=I*E
and E=I*R) as were used in the tube circuits. The only
major difference was the lower voltages and smaller
currents involved, which meant you could use smaller
components rated at a lower wattage.
The microchip, or integrated circuit, reduced the
required voltage even more, and the trend continues.
In order to reduce the heat created by ever-faster
microprocessors, dual voltages were created, so that
the CPU in my computer runs on an internal voltage of
only 1.75 volts, and communicates with the motherboard
using a slightly higher voltage of 3.3 volts.
Additionally, the peripheral components needed to
control the voltages delivered to the 'transistors'
built in to a microchip are now an integral part
of the chip itself. To that extent, calculating
circuit values for voltage and current has been
essentially eliminated, since the complete circuits
have been built into the chips themselves.
I hope that helps...
Additional searches done, via Google:
"transition from tubes"
formula choose tube
formula choose tube circuit
formula choose electron tube circuit