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ABC - Computer - MiniHistory
Aided Computation in the Era

Table of Contents
    - Mini-History
    - Definitions, or lack thereof, a source of argumentative heat
    - Who invented the Computer? - comments
    - Some other electronic digital computing devices not included in the above lists

The following "history" ignores "data processing", ie inventory, billing, payroll, ..., "Social Security" operations, etc. These are problems characterized by large amounts of input and output, and not many adds, subtracts, multiplies per bill, paycheck, ... . Large companies (such as IBM with the 601 electrical multiplier - one per second ) were satisfying this world.

We focus on "scientific computing" where there are frequently thousands of adds, subtracts, (and maybe multiplies, divides), per "answers" or "line of output".

I chose to ignore the interesting analog world of "Differential Analyser", analog control systems, ...
    And also to ignore computing aids such as the abacus, slide rules, log and other tables, ...

  1. In the 1830, Babbage worked out a "difference engine" that used successive additions to evaluate (and print as part of the error reduction plan) polynomials, got funds to make one, and fizzled.
        see Charles Babbage's Difference Engine No. 2 Technical Description
        and Babbage Difference Engine #2 - How to Initialize the Machine -

  2. Early 1930s, using punched card processing motions of the moon Comrie for large scale scientific computing, then Columbia University for astronomical computing

  3. (Konrad Zuse's machines here, Wikipedia and Horst Zuse Z-1, Z-2 and Z-3 machines were much more general, programmable, and even eventually provided hardware floating point. But they used relays as switching/amplifying elements, in part because he had even less money, time and procurement clout. )

  4. Bell Labs (telephones) Complex Number Calculator 1939 by George Stibitz and S. B. Williams     - Calculate with complex numbers (A+iB)
        - Used relays (several thousand times slower than vacuum tubes)
        - Daily use at Bell Labs problems until 1949
        - Disassembled, Recreation at the Smithsonian

  5. 1940, Iowa State College (your basic agricultural college) by John Atanasoff
            see John Vincent Atanasoff & the Birth of the Digital Computer
        - Special purpose, solve large (30 variable) simultaneous equations quickly
            Intermediate results were punched into cards
            and an operator had to reload the cards for reading for further passes.
            (If he had been able to construct about 15 times more storage,
            the process could have been made fully automatic.)
        - He got a grant and did afford vacuum tubes (several thousand times faster than relays)
                His machine did 30 bit serial additions (50 bits each) (in parallel) per second.
        - Worked quite well, thank you - except for punching the intermediate results -
        - Original machine was later neglected,
            -- later was too wide to fit through a new door, and destroyed.
        - Reconstruction by and at Iowa State University. Funded from private sources.

  6. Harvard & IBM by Howard Aiken
        1944 Harvard Mark 1 - *big*, relays, sponsered in part by IBM

  7. Another claimant for first electronic computer, the British Colossus at Bletchley Park entered service December 1943, about 2 years after ABC was abandoned for WWII). Both used glass enclosed electronic tubes. ABC used the more common vacuum tubes, the Colossus (and later Colossi ;-)) used gas filled electronic tubes - thyratrons.

  8. The well known ENIAC, was unveiled on February 14, 1946.
Most of the above can be found in the excellent A History of Computing Technology by Michael R. Williams

Definitions, or lack thereof, a source of argumentative heat
It is usual that when someone says ... was the first ... ,
    an enormous amout of argument and heat are often quickly generated.
Some times the result first depends on
    - a race to a patent office (telephone)
    - part of a system (the electric light)
few are as clean cut as
    - the (powered) airplane (the Wright Brothers).

In the case of "computer", the first "computers" were humans who did a lot of arithmetic, often for pay.

Current conventional usage of "computer" is not a human but some machine able to do arithmetic, with some means of getting information in and out, and usually with included internal storage.

When discussing current "computers",
    * especially when prefixed with the word "first"
we now need lots of qualification adjectival weasel words such as:
    - Turing Complete
    - programmable
    - automatic
    - "special purpose" or "general purpose" or "imbedded"
    - electronic, with subqualifiers of "hard valve", "soft valve", "solid state", ...
    - Harvard or von Neumann memory access
    - ... (I've barely started.) ... "personal", mini, micro, performance, ...
with people getting all bent out of shape and unpleasant.
    If fame and/or fortune are involved things can get worse !!
lets not get into the strange deaths of
    - Rudolf Diesel ( inventor of the Diesel engine, in the middle of a patent fight )
    - Clifford Berry ( near the start of ENIAC patent negotiations between IBM and SperryRand )

To carry on further, general purpose computers such as the IBM 1401 did not have multiply or divide in the basic machine - which did multiply and divide as software subroutines. The hardware multiply and divide was an option.

And further, many early non-human "computers" were "special purpose"
    - Stibitz (four function arithmetic with complex numbers)
    - ABC (simultaneous equation solver)
    - ENIAC (differential analyser, complete with accumulators,integrators) until retrofitted later
Many recent computers, such as in your car, TV, cell phone, microwave oven, ... are by almost any definition you can use "special purpose" - they are hard wired to do a very limited subset of "Turing Complete" ;-))

One could say that we have come "full circle" except that you can mass produce "micro computers" for less than $0.50 each :-))

Who invented the Computer? - comments
Executive Summary:
I may be a slow learner -
    but even I know enough not to leap into where angels fear to tread. ;-))

I am a gradualist, an incrementalist - isolated lightning doesn't happen very often -
    Most "inventions" are not very great steps, part of a series of steps -
and with out the many "lower" steps (inventions and/or improvements)
    what ever great invention you are talking about would not be possible.

Sir Isaac Newton, developer/inventor of the first practical reflecting telescope, among many other things - is reputed to have said "If I have seen further it is only by standing on the shoulders of giants."

  • Babbage could not have "invented" the "electronic" computer because amplifying "valves" had not been invented yet (by de Forest).
  • Zuse did not invent the "electronic" computer because he couldn't afford tubes and was not familiar with them.
  • And "what is a computer" changes over time - We now think a computer has to have
    1. a nice flat display screen - inexpensive only in the last 10 years
    2. a disk ( 1000 pound 5 mega-characters models available in 1960 )
    3. a keyboard - maybe 1955 for early adopters
    4. a reliable (and non-mercury ;-) memory, drums in about 1953? core in about 1959
    5. a B-Box ( index register ), so that you can call a subroutine with out modifing code,
      invented by the Brits for the Manchester Mark 1 in 1949 .
    6. none of the early "computers" were "stored program", memory was just too expensive to waste to store a program into. This includes Zuse, Atanasoff, ENIAC, ...
          ZUSE Z3 could store (64 words, each comprising 22 bits)
          The ABC computer could store 60 numbers of 50 bits each - 2 drums of 1500 bits each
          The ENIAC could store 20 numbers of 10 decimal digits each

There was a patent case before Judge Larson in Minneapolis -
    and considerable comment -
For a little background in courts and patents, one can examine this commentary on the patent fight involving Marconi in front of the U. S. Supreme Court. In part, this commentary states
"What can we learn from these discordant interpretations? A court opinion in a patent case can be difficult reading, and historians should be mistrustful of secondhand analysis. ... "
and The Trial

So - when you tell me what you regard as a computer, and with some prodding, I might venture an opinion as to who "invented" it :-))

Some other electronic digital computing devices not included in the above lists
Folks don't like it when some early computing devices are left out
    - British "Bombe"s. decoding Enigma, electro-mechanical
The following appeared after the non-stored program ENIAC above:
    - Manchester "Baby", THE real first stored program electronic computer
    - Turing Computer - I'm glad I did not have to program that - I'm not a genius
    - Leo - the first business oriented stored program machine

If you have comments or suggestions, Send e-mail to Ed Thelen

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