Eniac was indeed impressive and an important milestone. I recommend the 1999 book "ENIAC - The triumphs and tragedies of the world's first computer" by Scott McCartney which is both interesting to read and very informative. Also the review of the book by the late Jean Bartik, one of the "computers" and thus an eyewitnmess, is very interesting: https://web.archive.org/web/20221101120020/https://www.amazo....
Though the article is very US focussed, keeping quiet that German engineer Konrad Zuse completed the Z3 in May 1941, five years before ENIAC, effectively creating the world's first working programmable and fully automatic digital computer. While ENIAC required days of manual cable patching to program, the Z3 was quickly programmed by a punched tape ("Lochstreifen"), and Zuse also has invented PlankalkĆ¼l between 1942 and 1945, which is widely recognized as the world's first high-level programming language. The cooperation between Zuse and ETH Zurich eventually led to the first self-compiling compiler and eventually Algol 60 (see "The European Side of the Last Phase of the Development of ALGOL 60" by Peter Naur in ACM SIGPLAN "History of Programming Languages" from 1978). And there was also the British Colossus, which was also a "programmable computer" and successfully utilized vacuum tubes for code-breaking by early 1944.
There are three main problems with trying to offer a simple answer to the question of "what is the first computer?"
The most obvious of the problems is that a computer isn't a singular technology that springs up de novo, but something that develops from antecedents over a long, messy transition problem that requires a judgement call as to when the proto-computer becomes an actual computer. A judgement call which is obviously going to be biased based on the other considerations. Consider, for a more contemporary example, what you would argue as the "first smartphone" or the "first LLM." Personally, I think the ENIAC is still somewhat too proto-computer for my tastes: I'd prefer a "first" that uses binary arithmetic and has stored programs, neither of which is true for the ENIAC.
The second major issue is it's also instructive to look at the candidates' influence on later development. Among the contenders for "first computer," it's unfortunately kinda clear that ENIAC has the most lasting influence. ENIAC's development produced the papers that directly inspires the next generation of machines. Colossus is screwed here because of the secrecy of the code-breaking effort. Meanwhile, Zuse and Z3 suffer from being on the losing end of WW2. ABC has a claim here, but it's not clear whether or not the developers of ENIAC drew influence from ABC or not.
The final major issue isn't so much an issue by itself but rather something that colors the interpretation of the first two issues: national pride. An American is far more likely to weight the influence and ingenuity of the ENIAC and similar machines to label one of them the "first computer." A UK person would instead prefer to crown Colossus or the Manchester Baby. A German would prefer the Z3.
In many ways the ENIAC was more like an FPGA than a computer. It was programmed with patch cables connecting the different computational units as well as switches, and had no CPU as such. The cables had to be physically rerouted when changing to a new program, which took weeks. My understanding is that it was eventually programmed to emulate a von Neuman machine around 1948/49. As far as I understand, this was done mainly by Jean Bartik based on Von Neumans ideas.
If this is correct, it was not a von Neuman machine originally, but it eventually became one, and at approximately the same time as the Manchester Baby.
The Z3 was only general purpose by accident, and this was only discovered in 1997 (published 1998). [0] It's only of theoretical interest because the technique required is too inefficient for real-world applications.
ENIAC is notable because it was the first intentionally general purpose computer to be built.
I do not think that it is right at all to say "intentionally general purpose computer".
ENIAC was built for a special purpose, the computation of artillery tables.
It was a bespoke computer built for a single customer: the United States Army's Ballistic Research Laboratory.
This is why it has been designed as the digital electronic equivalent of the analog mechanical computers that were previously used by the Army and why it does not resemble at all what is now meant by "general-purpose computer".
The computers of Aiken and Zuse were really intentionally general-purpose, their designers did not have in mind any specific computation, which is why they were controlled by a program memory, not by a wiring diagram.
What you claim about Z3 being general purpose by accident does not refer to the intention of its designer, but only to the fact that its instruction set was actually powerful enough by accident, because at that early time it was not understood which kinds of instructions are necessary for completeness.
All the claims made now about ENIAC being general-purpose are retroactive. Only after the war ended and the concept of a digital computer became well understood, the ENIAC was repurposed to also do other tasks than originally planned.
The first truly general-purpose electronic digital computers that were intentionally designed to be so were those designed based on the von Neumann report.
Before the completion of the first of those, there were general-purpose hybrid electronic-electromechanical digital computers, IBM SSEC being the most important of them, which solved a lot of scientific and technical problems, before electronic computers became available.
A counter argument is that Mauchly was actually interesting in using computers for weather modeling and Iām sure that influenced the design of ENIAC. He could only get ENIAC funded if it was valuable to the war effort. Iāve read quite a lot about that machine and Iām not aware of any architectural features that were specific to ballistics calculations. This is unlike the British Colossus, another early computer, which was specifically designed for code breaking and wasnāt general purpose.
As for the objection that it wasnāt stored program, I was interested to learn that it was converted to stored program operation after only two years or so of operation, using the constant table switches as the program store. But the Manchester Baby, which used the same memory for code and data was more significant in the history of stored program machines.
On the general question of āfirst computerā, I think the answer is whatever machine you want it to be if you heap enough conditional adjectives on it.
> Mauchly was actually interesting in using computers for weather modeling and Iām sure that influenced the design of ENIAC
True. Mauchly was a physics professor interested in meterology, and he knew that predicting the weather and calculating an artillery shell's flight are mathematically the same type of problem, which was important to get funding. In the fifties, Eniac was even used to calculate weather forecasts (see https://ams.confex.com/ams/2020Annual/webprogram/Manuscript/...). So these were just two related special problems, and it would be a stretch to interpret this as an intention to build a general-purpose computer. The latter had to wait until the sixties.
> The Z3 was only general purpose by accident ... ENIAC [..] was the first intentionally general purpose computer
That's a pretty academic take. Neither Eckert, nor Mauchly, nor Zuse knew about Alan Turingās 1936 paper when they designed their machines. The classification of ENIAC (and the Z3) as a "universal Turing machine" is entirely a retroactive reinterpretation by later computer scientists. John von Neumann knew the paper and was aware of its significance, but he only turned up in the ENIAC project when the design was complete. At this time, Eckert and Mauchly were already well aware of ENIAC's biggest flaw (the massive effort to reprogram the machine, and in fact they came up with the stored-program concept which von Neumann later formalized). ENIACās funding and primary justification were for the very specific purpose of calculating artillery firing tables for the military. The machine was built for this purpose, which included the feature which retroactively led to the mentioned classification.
Still feels like history written by the victors (of WW2 and computing, eventually) in this case. If you want to be mathematically precise, it's been proven to be Turing-complete. If you want to use common sense (IMO better), it was one of the most significant leaps in automated computation and simply didn't need to do more for its intended applications. For conditional branches to make sense, you also need a fast temporary storage array (since it would be awfully slow running directly off tape like a Turing machine), and to realize that all that effort makes sense, you first need to play with a computer for a while and discover the new possibilities.
The Z3 was not a general purpose computer; it was a calculator that performed a predetermined sequence of operations that was written to its tape. It was remarkable for being all-binary in an era when differential gears and cams were very common in computing devices, and had some other advanced features. But the 1990s article that declared it Turing-complete is just silly. It would apply to every four-function calculator that supports rounding, and programming a computer like that is not just "impractical" - both the tape and execution time would grow exponentially in number of branches - but it is not the model that Turing proposed. The whole point of Turing's (theoretical) device is that a short program using the abilities of that device could perform unlimited computations; if you make the program length unlimited instead, that's a much less interesting model of computation.
The problem is that anything that gets into Wikipedia becomes ingrained in the Internet's collective mind, which then can't be changed.
What the article says is different: "the first large-scale, general-purpose, programmable electronic digital computer".
The claim of the article can be considered correct, and "electronic" is a part that cannot be deleted from it without falsifying the claim.
Before ENIAC, there have been digital computers that were much more general-purpose, because they run programs written on punched tape, instead of requiring a rewiring like ENIAC.
ENIAC, which evolved from the analog computers known as differential analyzers, had a structure closer to an FPGA than to a modern digital computer.
In contrast, an earlier relay computer like Harvard Mark I was intended as a successor of the mechanical digital computer designed by Charles Babbage, so it already had the same structure with a modern digital computer, except that it used different kind of memories for data and for programs, hence the name "Harvard architecture". The same was true for the Zuse computer.
The earlier ABC digital computer was electronic, but it can be considered as special-purpose, not general-purpose. The first relay computers at Bell Labs may also be considered as special purpose.
For ENIAC it also does not make sense to claim that it was Turing complete. Such a claim can be made for a computer controlled by a program memory, where you have a defined instruction set, and the instruction set may be complete or not. If you may rewire arbitrarily the execution units, any computer is Turing complete.
The earlier ABC electronic computer was built for a special purpose, the solution of systems of linear algebraic equations, like ENIAC was built only for a special purpose, the computation of artillery tables.
By rewiring the ABC electronic computer you could have also computed anything, so you can say that it was Turing complete, if rewiring is allowed.
The only difference is that rewiring was simpler in ENIAC, because it had been planned to be easy, so there were special panels where you could alter the connections.
Neither ABC nor ENIAC had enough memory to be truly general-purpose, and by the end of the war it was recognized that this was the main limitation for extending the domain of applications, so the ENIAC team proposed ultrasonic delay lines as the solution for a big memory (inspired by the use of delay lines as an analog memory in radars), while von Neumann proposed the use of a cathode ray tube of the kind used in video cameras (iconoscope; this was implemented first in the Manchester computers).
Because ENIAC was not really designed as general-purpose, its designers originally did not think about high-capacity memories. On the other hand, John Vincent Atanasoff, the main designer of the ABC computer, has written a very insightful document about the requirements for memories in digital computers, years before ENIAC, where he analyzed all the known possibilities and where he invented the concept of DRAM, but implemented with discrete capacitors. Later, the proposal of von Neumann was also to use a DRAM, but to use a cheaper and more compact iconoscope CRT, instead of discrete capacitors.
While the ABC computer was not general-purpose as built, the document written by Atanasoff in 1940, āComputing Machine for the Solution of Large Systems of Linear Algebraic Equationsā, demonstrated a much better understanding of the concept of a general-purpose electronic digital computer than the designers of ENIAC would demonstrate before the end of 1944 / beginning of 1945, when they realized that a bigger memory is needed to make a computer suitable for any other applications, i.e. for really making it "general purpose".
ENIAC was very important but this article overstates its significance and ignores other (non US) machines to the point of historical inaccuracy. No mention of Z3 or Manchester Baby for example, the latter based on the von Neumann paper for example, was arguably a more accurate pointer towards how computer architecture would develop.
ENIAC was far more important for the general computing industry than other machines of its time. ENIAC led to EMCC (the first computer company) and UNIVAC. It was UNIVAC and IBM struggling against one another that created the entire industry.
The paper came out of work on ENIAC and was adapted to follow the approach in the paper but Baby was built from outset to use that approach and its design much more closely matches the architecture that has been used by almost all digital computers since. I donāt dispute that ENIAC is important but itās role is more nuanced than this article implies.
ENIAC is where the profession of programming was born ā and the first programmers were six women: Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Meltzer, Frances Bilas, and Ruth Lichterman.
They had to program it by physically rewiring patch cables and flipping switches. There was no programming language, no stored program. The "software" was the hardware configuration itself.
It took another decade before FORTRAN (1957) gave programmers a way to write instructions in something resembling human language.
Thank you for highlighting the contributions of women in computing, especially at it's inception! That is so easily forgotten or intentionally ignored in the age of the "tech bro"
For a while I worked at what was then the Sperry Rand Corporation (now Unisys) which had some pride in their heritage as the descendant of the Univac Corporation founded by ENIAC inventors Eckert and Mauchly. In a glass case there was a vacuum tube circuit said to be a memory unit of the original ENIAC. No one seemed to know much about it, casting doubt on the claimed provenance of the device.
The tube circuit resembled the ones shown in the photo linked below (although none of those in the photo are from ENIAC).
> The computer contained about 18,000 vacuum tubes, which were cooled by 80 air blowers. More than 30 meters long, it filled a 9 m by 15 m room and weighed about 30 kilograms. It consumed as much electricity as a small town.
I still remember the CRT TV we had at home when I was kid. It was big but almost empty.
Vacuum tubes break too often. Once per year? But if you have a thousand of them you have to change one very often. So I guess they have a lot of space for humans repairing it.
Reminds me of stumbling across the Harvard Mark I, which is about 1-2 years older, while wandering through the Harvard Science Center (as one does). By far the oldest computer I've seen in person. Seems they moved it since then to the Science and Engineering Complex.
I find it interesting that, unless Iām mistaken, this was a completely engineering effort.
That is, they were not trying to follow the notion of a universal computing device that had already been defined by Turing and Church at the time. They were just trying to build something like a huge programmable calculator, but they ended up building a universal computation device anyway.
My alma mater, Ursinus, is a very small school and has few claims to fame; but one of them is that John Mauchly taught there before going to Penn to design ENIAC. Wikipedia puts it bluntly:
> Mauchly's teaching career truly began in 1933 at Ursinus College where he was appointed head of the physics department, where he was, in fact, the only staff member.
One of the engineers who worked on the Eniac lived next door to my old landlord in New Jersey. They played chess in the back yard. He was reputedly quite good.
Eniac was indeed impressive and an important milestone. I recommend the 1999 book "ENIAC - The triumphs and tragedies of the world's first computer" by Scott McCartney which is both interesting to read and very informative. Also the review of the book by the late Jean Bartik, one of the "computers" and thus an eyewitnmess, is very interesting: https://web.archive.org/web/20221101120020/https://www.amazo....
Though the article is very US focussed, keeping quiet that German engineer Konrad Zuse completed the Z3 in May 1941, five years before ENIAC, effectively creating the world's first working programmable and fully automatic digital computer. While ENIAC required days of manual cable patching to program, the Z3 was quickly programmed by a punched tape ("Lochstreifen"), and Zuse also has invented PlankalkĆ¼l between 1942 and 1945, which is widely recognized as the world's first high-level programming language. The cooperation between Zuse and ETH Zurich eventually led to the first self-compiling compiler and eventually Algol 60 (see "The European Side of the Last Phase of the Development of ALGOL 60" by Peter Naur in ACM SIGPLAN "History of Programming Languages" from 1978). And there was also the British Colossus, which was also a "programmable computer" and successfully utilized vacuum tubes for code-breaking by early 1944.
There are three main problems with trying to offer a simple answer to the question of "what is the first computer?"
The most obvious of the problems is that a computer isn't a singular technology that springs up de novo, but something that develops from antecedents over a long, messy transition problem that requires a judgement call as to when the proto-computer becomes an actual computer. A judgement call which is obviously going to be biased based on the other considerations. Consider, for a more contemporary example, what you would argue as the "first smartphone" or the "first LLM." Personally, I think the ENIAC is still somewhat too proto-computer for my tastes: I'd prefer a "first" that uses binary arithmetic and has stored programs, neither of which is true for the ENIAC.
The second major issue is it's also instructive to look at the candidates' influence on later development. Among the contenders for "first computer," it's unfortunately kinda clear that ENIAC has the most lasting influence. ENIAC's development produced the papers that directly inspires the next generation of machines. Colossus is screwed here because of the secrecy of the code-breaking effort. Meanwhile, Zuse and Z3 suffer from being on the losing end of WW2. ABC has a claim here, but it's not clear whether or not the developers of ENIAC drew influence from ABC or not.
The final major issue isn't so much an issue by itself but rather something that colors the interpretation of the first two issues: national pride. An American is far more likely to weight the influence and ingenuity of the ENIAC and similar machines to label one of them the "first computer." A UK person would instead prefer to crown Colossus or the Manchester Baby. A German would prefer the Z3.
In many ways the ENIAC was more like an FPGA than a computer. It was programmed with patch cables connecting the different computational units as well as switches, and had no CPU as such. The cables had to be physically rerouted when changing to a new program, which took weeks. My understanding is that it was eventually programmed to emulate a von Neuman machine around 1948/49. As far as I understand, this was done mainly by Jean Bartik based on Von Neumans ideas.
If this is correct, it was not a von Neuman machine originally, but it eventually became one, and at approximately the same time as the Manchester Baby.
The Z3 was only general purpose by accident, and this was only discovered in 1997 (published 1998). [0] It's only of theoretical interest because the technique required is too inefficient for real-world applications.
ENIAC is notable because it was the first intentionally general purpose computer to be built.
[0] https://www.inf.fu-berlin.de/inst/ag-ki/rojas_home/documents...
I do not think that it is right at all to say "intentionally general purpose computer".
ENIAC was built for a special purpose, the computation of artillery tables.
It was a bespoke computer built for a single customer: the United States Army's Ballistic Research Laboratory.
This is why it has been designed as the digital electronic equivalent of the analog mechanical computers that were previously used by the Army and why it does not resemble at all what is now meant by "general-purpose computer".
The computers of Aiken and Zuse were really intentionally general-purpose, their designers did not have in mind any specific computation, which is why they were controlled by a program memory, not by a wiring diagram.
What you claim about Z3 being general purpose by accident does not refer to the intention of its designer, but only to the fact that its instruction set was actually powerful enough by accident, because at that early time it was not understood which kinds of instructions are necessary for completeness.
All the claims made now about ENIAC being general-purpose are retroactive. Only after the war ended and the concept of a digital computer became well understood, the ENIAC was repurposed to also do other tasks than originally planned.
The first truly general-purpose electronic digital computers that were intentionally designed to be so were those designed based on the von Neumann report.
Before the completion of the first of those, there were general-purpose hybrid electronic-electromechanical digital computers, IBM SSEC being the most important of them, which solved a lot of scientific and technical problems, before electronic computers became available.
A counter argument is that Mauchly was actually interesting in using computers for weather modeling and Iām sure that influenced the design of ENIAC. He could only get ENIAC funded if it was valuable to the war effort. Iāve read quite a lot about that machine and Iām not aware of any architectural features that were specific to ballistics calculations. This is unlike the British Colossus, another early computer, which was specifically designed for code breaking and wasnāt general purpose.
As for the objection that it wasnāt stored program, I was interested to learn that it was converted to stored program operation after only two years or so of operation, using the constant table switches as the program store. But the Manchester Baby, which used the same memory for code and data was more significant in the history of stored program machines.
On the general question of āfirst computerā, I think the answer is whatever machine you want it to be if you heap enough conditional adjectives on it.
> Mauchly was actually interesting in using computers for weather modeling and Iām sure that influenced the design of ENIAC
True. Mauchly was a physics professor interested in meterology, and he knew that predicting the weather and calculating an artillery shell's flight are mathematically the same type of problem, which was important to get funding. In the fifties, Eniac was even used to calculate weather forecasts (see https://ams.confex.com/ams/2020Annual/webprogram/Manuscript/...). So these were just two related special problems, and it would be a stretch to interpret this as an intention to build a general-purpose computer. The latter had to wait until the sixties.
> The Z3 was only general purpose by accident ... ENIAC [..] was the first intentionally general purpose computer
That's a pretty academic take. Neither Eckert, nor Mauchly, nor Zuse knew about Alan Turingās 1936 paper when they designed their machines. The classification of ENIAC (and the Z3) as a "universal Turing machine" is entirely a retroactive reinterpretation by later computer scientists. John von Neumann knew the paper and was aware of its significance, but he only turned up in the ENIAC project when the design was complete. At this time, Eckert and Mauchly were already well aware of ENIAC's biggest flaw (the massive effort to reprogram the machine, and in fact they came up with the stored-program concept which von Neumann later formalized). ENIACās funding and primary justification were for the very specific purpose of calculating artillery firing tables for the military. The machine was built for this purpose, which included the feature which retroactively led to the mentioned classification.
Still feels like history written by the victors (of WW2 and computing, eventually) in this case. If you want to be mathematically precise, it's been proven to be Turing-complete. If you want to use common sense (IMO better), it was one of the most significant leaps in automated computation and simply didn't need to do more for its intended applications. For conditional branches to make sense, you also need a fast temporary storage array (since it would be awfully slow running directly off tape like a Turing machine), and to realize that all that effort makes sense, you first need to play with a computer for a while and discover the new possibilities.
The Z3 was not a general purpose computer; it was a calculator that performed a predetermined sequence of operations that was written to its tape. It was remarkable for being all-binary in an era when differential gears and cams were very common in computing devices, and had some other advanced features. But the 1990s article that declared it Turing-complete is just silly. It would apply to every four-function calculator that supports rounding, and programming a computer like that is not just "impractical" - both the tape and execution time would grow exponentially in number of branches - but it is not the model that Turing proposed. The whole point of Turing's (theoretical) device is that a short program using the abilities of that device could perform unlimited computations; if you make the program length unlimited instead, that's a much less interesting model of computation.
The problem is that anything that gets into Wikipedia becomes ingrained in the Internet's collective mind, which then can't be changed.
Would it not have been easy to add branch instructions to it? Just rewind the instruction tape however many places. It seems 99% of the job was done.
The shortened title is very incorrect.
What the article says is different: "the first large-scale, general-purpose, programmable electronic digital computer".
The claim of the article can be considered correct, and "electronic" is a part that cannot be deleted from it without falsifying the claim.
Before ENIAC, there have been digital computers that were much more general-purpose, because they run programs written on punched tape, instead of requiring a rewiring like ENIAC.
ENIAC, which evolved from the analog computers known as differential analyzers, had a structure closer to an FPGA than to a modern digital computer.
In contrast, an earlier relay computer like Harvard Mark I was intended as a successor of the mechanical digital computer designed by Charles Babbage, so it already had the same structure with a modern digital computer, except that it used different kind of memories for data and for programs, hence the name "Harvard architecture". The same was true for the Zuse computer.
The earlier ABC digital computer was electronic, but it can be considered as special-purpose, not general-purpose. The first relay computers at Bell Labs may also be considered as special purpose.
In this context, "general purpose" means "Turing complete" in the informal sense of handwaving away the requirement for infinite storage space.
What you say changes nothing.
The earlier relay computers were Turing complete.
For ENIAC it also does not make sense to claim that it was Turing complete. Such a claim can be made for a computer controlled by a program memory, where you have a defined instruction set, and the instruction set may be complete or not. If you may rewire arbitrarily the execution units, any computer is Turing complete.
The earlier ABC electronic computer was built for a special purpose, the solution of systems of linear algebraic equations, like ENIAC was built only for a special purpose, the computation of artillery tables.
By rewiring the ABC electronic computer you could have also computed anything, so you can say that it was Turing complete, if rewiring is allowed.
The only difference is that rewiring was simpler in ENIAC, because it had been planned to be easy, so there were special panels where you could alter the connections.
Neither ABC nor ENIAC had enough memory to be truly general-purpose, and by the end of the war it was recognized that this was the main limitation for extending the domain of applications, so the ENIAC team proposed ultrasonic delay lines as the solution for a big memory (inspired by the use of delay lines as an analog memory in radars), while von Neumann proposed the use of a cathode ray tube of the kind used in video cameras (iconoscope; this was implemented first in the Manchester computers).
Because ENIAC was not really designed as general-purpose, its designers originally did not think about high-capacity memories. On the other hand, John Vincent Atanasoff, the main designer of the ABC computer, has written a very insightful document about the requirements for memories in digital computers, years before ENIAC, where he analyzed all the known possibilities and where he invented the concept of DRAM, but implemented with discrete capacitors. Later, the proposal of von Neumann was also to use a DRAM, but to use a cheaper and more compact iconoscope CRT, instead of discrete capacitors.
While the ABC computer was not general-purpose as built, the document written by Atanasoff in 1940, āComputing Machine for the Solution of Large Systems of Linear Algebraic Equationsā, demonstrated a much better understanding of the concept of a general-purpose electronic digital computer than the designers of ENIAC would demonstrate before the end of 1944 / beginning of 1945, when they realized that a bigger memory is needed to make a computer suitable for any other applications, i.e. for really making it "general purpose".
ENIAC was very important but this article overstates its significance and ignores other (non US) machines to the point of historical inaccuracy. No mention of Z3 or Manchester Baby for example, the latter based on the von Neumann paper for example, was arguably a more accurate pointer towards how computer architecture would develop.
ENIAC was far more important for the general computing industry than other machines of its time. ENIAC led to EMCC (the first computer company) and UNIVAC. It was UNIVAC and IBM struggling against one another that created the entire industry.
IBM built the Harvard Mark 1 in 1944, before EMCC existed.
Wait, where are you thinking the von Neumann paper which came from?
The paper came out of work on ENIAC and was adapted to follow the approach in the paper but Baby was built from outset to use that approach and its design much more closely matches the architecture that has been used by almost all digital computers since. I donāt dispute that ENIAC is important but itās role is more nuanced than this article implies.
ENIAC is where the profession of programming was born ā and the first programmers were six women: Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Meltzer, Frances Bilas, and Ruth Lichterman.
They had to program it by physically rewiring patch cables and flipping switches. There was no programming language, no stored program. The "software" was the hardware configuration itself.
It took another decade before FORTRAN (1957) gave programmers a way to write instructions in something resembling human language.
Even in the 1950s, my mother worked on a machine that could be programmed in octal, but you could change the instruction set with patch cables.
Thank you for highlighting the contributions of women in computing, especially at it's inception! That is so easily forgotten or intentionally ignored in the age of the "tech bro"
For a while I worked at what was then the Sperry Rand Corporation (now Unisys) which had some pride in their heritage as the descendant of the Univac Corporation founded by ENIAC inventors Eckert and Mauchly. In a glass case there was a vacuum tube circuit said to be a memory unit of the original ENIAC. No one seemed to know much about it, casting doubt on the claimed provenance of the device.
The tube circuit resembled the ones shown in the photo linked below (although none of those in the photo are from ENIAC).
https://en.wikipedia.org/wiki/File:Women_holding_parts_of_th...
> The computer contained about 18,000 vacuum tubes, which were cooled by 80 air blowers. More than 30 meters long, it filled a 9 m by 15 m room and weighed about 30 kilograms. It consumed as much electricity as a small town.
Surprisingly light though...
The vacuum in the tubes weighs nothing, so they produce lift.
An obvious typo. It was tons, not kilograms.
Perhaps AI aided?
I still remember the CRT TV we had at home when I was kid. It was big but almost empty.
Vacuum tubes break too often. Once per year? But if you have a thousand of them you have to change one very often. So I guess they have a lot of space for humans repairing it.
Zuse Z3 enters the room, relais' kindly rattling "Hrm. I was digital. not electronic as in cathode tubes but definitively digital."
For the curious programmers who are wondering what it was like to program ENIAC, a simulator is available:
https://www.cs.drexel.edu/~bls96/eniac/simulator.html
And a programming manual:
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=846...
It's really got a nice archaic character.
Reminds me of stumbling across the Harvard Mark I, which is about 1-2 years older, while wandering through the Harvard Science Center (as one does). By far the oldest computer I've seen in person. Seems they moved it since then to the Science and Engineering Complex.
Colossus was first:
https://en.wikipedia.org/wiki/Colossus_computer
Arguably, it was the second.
The Harvard Mark 1 ran its first program in 1944, but didnāt have branches as we understand them until 1946:
https://en.wikipedia.org/wiki/Harvard_Mark_I
Apparently, you could achieve loops by taping the input program into a physical loop, even in 1944.
Colossus Mark I beat them too:
https://en.wikipedia.org/wiki/Colossus_computer
I find it interesting that, unless Iām mistaken, this was a completely engineering effort.
That is, they were not trying to follow the notion of a universal computing device that had already been defined by Turing and Church at the time. They were just trying to build something like a huge programmable calculator, but they ended up building a universal computation device anyway.
My alma mater, Ursinus, is a very small school and has few claims to fame; but one of them is that John Mauchly taught there before going to Penn to design ENIAC. Wikipedia puts it bluntly:
> Mauchly's teaching career truly began in 1933 at Ursinus College where he was appointed head of the physics department, where he was, in fact, the only staff member.
"More than 30 meters long, it filled a 9 m by 15 m room and weighed about 30 kilograms."
It was a balloon?
One of the engineers who worked on the Eniac lived next door to my old landlord in New Jersey. They played chess in the back yard. He was reputedly quite good.
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Unfortunately, if the subject doesn't have "AI", no one cares.
It has IA in its name so that must count for something.
That's AI in Spanish, so checks out in large parts of the world :)