ENIAC

The ENIAC, a name that whispers through the hushed halls of computing history, stood as the inaugural programmable, electronic, general-purpose digital computer. Its completion in 1945 marked a watershed moment, a culmination of features that, individually, had graced earlier machines, but never before had been so comprehensively integrated. It possessed the elusive Turing-complete capability, rendering it capable of tackling “a large class of numerical problems” simply through the elegant, albeit arduous, act of reprogramming.

Development and Design

The genesis of ENIAC, or more formally, the Electronic Numerical Integrator and Computer, was rooted in the urgent demands of the United States Army during World War II . Its primary commission was to calculate artillery firing tables for the Ballistic Research Laboratory at the Aberdeen Proving Ground in Aberdeen, Maryland . However, as is often the way with groundbreaking technology, its first true trial was a study into the feasibility of the thermonuclear weapon , a testament to its raw computational power and the ambitious scope of scientific inquiry it enabled.

The project, financed by the U.S. Army Ordnance Corps under the leadership of Major General Gladeon M. Barnes , carried a hefty price tag of approximately $487,000, a sum that, adjusted for inflation, would be around $7,000,000 in 2024. The seeds of ENIAC were sown in June 1941, a time when the Army was relying on the laborious calculations of Friden calculators and differential analyzers , often performed by graduate students under the watchful eye of John Mauchly . Mauchly, a visionary who dared to question the limitations of existing technology, began to ponder the transformative potential of electronics in accelerating mathematical computations. He found a crucial collaborator in J. Presper Eckert , a research associate who possessed the electrical engineering prowess that Mauchly lacked. Together, they embarked on drafting a design for an electronic computer that promised unprecedented speed. By August 1942, Mauchly had formally proposed an all-electronic machine, a concept that resonated with the Army’s need for rapid ballistic calculations. Their plan was embraced, leading to a six-month research contract from the University of Pennsylvania for $61,700.

The formal construction contract was inked on June 5, 1943, and the secret work commenced the following month at the University of Pennsylvania ’s Moore School of Electrical Engineering . Operating under the clandestine code name “Project PX,” with John Grist Brainerd at the helm as principal investigator, the project gained momentum. Herman H. Goldstine , a pivotal figure, convinced the Army to fully fund the endeavor, positioning himself to oversee its progress. Assembly of the colossal machine began in June 1944, and by September of that year, Eckert and Mauchly had finalized their groundbreaking design. The physical construction was completed by May 1945, initiating a period of rigorous testing at the Moore School. Later that year, in November, Mauchly, Eckert, John Brainerd , and Herman Goldstine jointly published the first confidential report detailing the computer’s functionality and programming methods, a document that offered a glimpse into the future of computation.

The intellectual architects of ENIAC were John Mauchly , a physics professor from Ursinus College , and J. Presper Eckert of the University of Pennsylvania . Their design team was a formidable assembly of engineering talent, including Robert F. Shaw, responsible for the intricate function tables; Jeffrey Chuan Chu , who tackled the divider and square-rooter units; Thomas Kite Sharpless and Frank Mural, the master programmers; Arthur Burks , who engineered the multiplier; Harry Huskey , who devised the reader/printer mechanisms; and Jack Davis, who managed the accumulators. However, the unsung heroes, the ones who breathed life into the machine’s logic through programming, were a cadre of brilliant women: Jean Jennings , Marlyn Wescoff , Ruth Lichterman , Betty Snyder , Frances Bilas , and Kay McNulty . In the wake of ENIAC’s completion, this core group of innovators departed the University of Pennsylvania to establish the Eckert–Mauchly Computer Corporation , a venture that would further shape the nascent computer industry.

ENIAC was conceived as a modular behemoth, a network of interconnected panels, each dedicated to a specific computational task. Twenty of these modules were the accumulators, sophisticated units capable not only of addition and subtraction but also of storing ten-digit decimal numbers. Data flowed between these units via general-purpose buses , referred to as “trays.” The pursuit of speed necessitated that these panels execute input, computation, storage, and the triggering of subsequent operations with an astonishing lack of mechanical movement. A crucial element of ENIAC’s adaptability was its ability to branch , allowing it to execute different operational sequences based on the results of calculations, such as the sign of a computed value.

Components

By the time of its decommissioning in 1956, ENIAC was a monument to early electronics, comprising an astonishing 18,000 vacuum tubes , 7,200 crystal diodes , 6,000 relays , 70,000 resistors , and 10,000 capacitors . The sheer scale of its construction was underscored by approximately 5,000,000 hand-soldered joints. This titan of computation weighed over 30 short tons (27 metric tons), stood approximately 10 feet (3 meters) tall, was 3 feet (1 meter) deep, and stretched an imposing 100 feet (30 meters) in length, occupying a substantial 300 square feet (28 m²). Its voracious appetite for power was satisfied by a 150 kW electricity supply. Data input was managed by an IBM card reader , and output was handled by an IBM card punch . These punched cards could then be fed into an IBM accounting machine, such as the IBM 405 , for offline printed output. While ENIAC was not initially equipped with internal memory storage, these punch cards served as an external repository for data. A significant upgrade arrived in 1953 with the addition of a 100-word magnetic-core memory module, manufactured by the Burroughs Corporation .

ENIAC’s numerical prowess was built upon ten-position ring counters for digit storage, with each digit requiring a considerable 36 vacuum tubes, 10 of which were dual triodes forming the flip-flops of the ring counter itself. Arithmetic operations were executed by “counting” pulses, mimicking the mechanical digit wheels of an adding machine , with carry pulses generated when a counter “wrapped around.”

The machine boasted 20 ten-digit signed accumulators , employing ten’s complement representation. These accumulators could perform up to 5,000 simple addition or subtraction operations per second between any two units or a constant transmitter. The capacity for parallel operation, by connecting multiple accumulators to work simultaneously, allowed for potentially much higher peak operational speeds.

A glimpse into the operational intricacies of ENIAC reveals its advanced capabilities. It was possible to wire the carry output of one accumulator into another to achieve double precision in arithmetic operations. However, timing constraints within the accumulator carry circuit precluded the chaining of three or more for even greater precision. For multiplication, ENIAC employed four accumulators, guided by a specialized multiplier unit, capable of executing up to 385 operations per second. Division and square root calculations were handled by a dedicated unit connected to five accumulators, performing up to 40 divisions or 3 square root operations per second.

Beyond the computational modules, ENIAC comprised an initiating unit for starting and stopping the machine, a cycling unit for synchronizing operations, a master programmer to manage loop sequencing, a reader to control the IBM card reader, a printer for the IBM card punch, a constant transmitter, and the aforementioned three function tables.

Operation Times

Detailed analyses by Rojas and Hashagen, or Wilkes, offer a more granular understanding of ENIAC’s operational speeds, with figures that sometimes vary slightly from other sources. The fundamental machine cycle spanned 200 microseconds , equivalent to 20 cycles of the 100 kHz clock within the cycling unit, thus facilitating 5,000 cycles per second for operations involving 10-digit numbers. Within a single cycle, ENIAC could perform tasks such as writing a number to a register, reading from a register, or executing an addition or subtraction.

Multiplication of a 10-digit number by a d-digit number (where d could be up to 10) required d+4 cycles. Consequently, multiplying two 10-digit numbers took 14 cycles, translating to 2,800 microseconds, or a rate of 357 multiplications per second. Operations involving numbers with fewer than 10 digits were, naturally, faster.

Division and square root calculations were more time-intensive, requiring 13(d+1) cycles, where ’d’ represented the number of digits in the result (the quotient or square root). This meant a division or square root could take up to 143 cycles, or 28,600 microseconds, yielding a rate of approximately 35 operations per second. Wilkes (1956) noted that a division resulting in a 10-digit quotient demanded around 6 milliseconds. As with multiplication, operations producing results with fewer than ten digits were executed more swiftly.

In terms of raw processing power, ENIAC could achieve roughly 500 FLOPS . To put this into perspective, this is a minuscule fraction of the petascale and exascale capabilities found in modern supercomputers .

Reliability

ENIAC relied on common octal-base radio tubes prevalent at the time. Its decimal accumulators were constructed from 6SN7 flip-flops , while logic functions utilized tubes such as 6L7s, 6SJ7s, 6SA7s, and 6AC7s. Numerous 6L6s and 6V6s served the vital role of line drivers, transmitting pulses through cables connecting the various rack assemblies.

The Achilles’ heel of early electronics was its fragility. Several tubes would burn out almost daily, rendering ENIAC inoperable for roughly half its operational time. High-reliability tubes, a solution to this pervasive issue, did not become readily available until 1948. However, a significant portion of these failures occurred during the thermal stresses of warm-up and cool-down periods. Through diligent engineering efforts, the rate of tube failures was eventually reduced to a more manageable level of approximately one tube every two days. J. Presper Eckert, in a 1989 interview, recalled, “We had a tube fail about every two days and we could locate the problem within 15 minutes.” In 1954, the longest uninterrupted operational period without a failure was recorded at 116 hours, nearly five full days.

Programming

ENIAC possessed the capability to be programmed for intricate sequences of operations, including loops and branches. However, unlike the stored-program computers that define modern computing, ENIAC was essentially a vast collection of arithmetic machines. Its programs were initially set by a laborious process involving plugboard wiring and the manual manipulation of three portable function tables, each equipped with 1,200 ten-way switches. The task of translating a problem into a configuration that ENIAC could understand was a complex undertaking, often consuming weeks. Consequently, program changes were infrequent, typically undertaken only after extensive testing of the existing configuration. Once a program was meticulously worked out on paper, the physical act of wiring ENIAC’s switches and cables could take days, followed by a crucial period of verification and debugging, aided by the machine’s capacity for step-by-step execution. For those seeking a practical understanding, a tutorial simulating ENIAC’s programming of the modulo function offers a compelling insight into the nature of these early programs.

The six primary programmers of ENIAC—Kay McNulty , Betty Jennings , Betty Snyder , Marlyn Wescoff , Fran Bilas , and Ruth Lichterman —not only mastered the art of inputting ENIAC programs but also developed a profound understanding of its internal workings. Their expertise often allowed them to pinpoint faulty tubes, enabling technicians to replace them efficiently.

Programmers

During World War II , the U.S. Army’s burgeoning need for ballistic trajectory calculations led to the recruitment of numerous women. At least 200 women were employed by the Moore School of Engineering as “computers ,” and from this pool, six were selected to become the pioneering programmers of ENIAC. These remarkable individuals—Betty Holberton , Kay McNulty , Marlyn Wescoff , Ruth Lichterman , Betty Jean Jennings , and Fran Bilas —were tasked with electronically calculating ballistic trajectories for the Army’s Ballistic Research Laboratory . It is a stark historical irony that while men with equivalent education and experience were designated “professionals,” these women, despite possessing professional degrees in mathematics and undergoing rigorous training, were relegated to “subprofessional” status.

Contrary to certain historical narratives, these women were not mere models posing for press photographs; their role was far more substantive. This fact was brought to light through the diligent research of undergraduate computer scientist Kathryn Kleiman, who uncovered a history often obscured by traditional accounts. Tragically, some of these women received little to no recognition for their monumental contributions during their lifetimes. As the war concluded, their expertise became indispensable, making it challenging to replace them with returning soldiers. It was only in the 1990s that Kleiman, upon discovering that most of the ENIAC programmers had not been invited to the machine’s 50th-anniversary celebration, embarked on a mission to locate them and record their oral histories. “They were shocked to be discovered,” Kleiman recounted. “They were thrilled to be recognized, but had mixed impressions about how they felt about being ignored for so long.” Her dedication culminated in the release of a book in 2022 dedicated to these six pioneering women.

These early programmers were drawn from a larger group of approximately two hundred women employed as “computers ” at the Moore School of Electrical Engineering . Their primary role was to meticulously produce the numerical results of complex mathematical formulas required for scientific and engineering projects, typically using mechanical calculators. The ENIAC programmers, however, delved deeper, studying the machine’s logic, physical structure, and circuitry. This immersive approach allowed them not only to grasp the mathematics of computing but also to intimately understand the machine itself. This technical role represented one of the few avenues available to women in the workforce at that time. Betty Holberton (née Snyder), a key figure, went on to co-author the first generative programming system (SORT/MERGE ) and played a crucial role in designing the first commercial electronic computers, the UNIVAC and the BINAC , alongside Jean Jennings. McNulty, another of the six, pioneered the use of subroutines to enhance ENIAC’s computational capacity.

Herman Goldstine personally selected these programmers, whom he termed “operators,” from the ranks of women who had been calculating ballistics tables using mechanical desk calculators and a differential analyzer prior to and during ENIAC’s development. Under the guidance of Herman and Adele Goldstine , these women studied ENIAC’s blueprints and physical architecture, deciphering how to manipulate its switches and cables—a critical skill in an era before the advent of programming languages . Although programming was widely regarded as a clerical task and the programmers’ pivotal role in ENIAC’s successful operation and public announcement went largely unrecognized by their contemporaries, the contributions of McNulty, Jennings, Snyder, Wescoff, Bilas, and Lichterman have since been widely acknowledged. As a testament to their legacy, three of the U.S. Army’s current (as of 2020) supercomputers bear their names: Jean, Kay, and Betty, honoring Jean Bartik (née Betty Jennings), Kay McNulty , and Betty Snyder , respectively.

The roles of “programmer” and “operator” were not initially considered professions suitable for women. The severe labor shortage brought about by World War II proved instrumental in opening doors for women in these technical fields. However, the perception persisted that these roles were not prestigious, and the enlistment of women was viewed as a strategic move to free up men for more specialized labor, essentially a temporary solution to a wartime crisis. The National Advisory Committee for Aeronautics, in a 1942 document, noted, “It is felt that enough greater return is obtained by freeing the engineers from calculating detail to overcome any increased expenses in the computers’ salaries. The engineers admit themselves that the girl computers do the work more rapidly and accurately than they would. This is due in large measure to the feeling among the engineers that their college and industrial experience is being wasted and thwarted by mere repetitive calculation.”

Following the initial six programmers, an expanded team of around one hundred scientists was assembled to continue work on ENIAC. Among this group was Gloria Ruth Gordon , another notable female contributor. Adele Goldstine authored the original technical description of the ENIAC, a foundational document for understanding its architecture.

Programming Languages

The evolution of programming for ENIAC saw the development of several distinct language systems, each designed to bridge the gap between human intent and machine execution.

Role in the Hydrogen Bomb

Although ENIAC’s primary sponsor was the Ballistic Research Laboratory, its immense computational power soon attracted the attention of John von Neumann , a mathematician deeply involved in the hydrogen bomb project at Los Alamos National Laboratory . By December 1945, ENIAC was being utilized to calculate thermonuclear reactions using complex equations . The data generated from these calculations played a crucial role in supporting research efforts aimed at developing a hydrogen bomb.

Role in Development of Monte Carlo Methods

ENIAC’s involvement in the hydrogen bomb project also significantly contributed to the burgeoning popularity of the Monte Carlo method . Scientists engaged in early nuclear bomb development relied on vast teams of human “computers” to perform extensive calculations, particularly to estimate the distance neutrons would travel through various materials. John von Neumann and Stanislaw Ulam recognized that ENIAC’s extraordinary speed could drastically accelerate these calculations. The success of this endeavor underscored the profound value of Monte Carlo methods in scientific research.

Later Developments

A public unveiling of ENIAC occurred at a press conference on February 1, 1946, followed by a formal announcement to the public on the evening of February 14, 1946, complete with demonstrations of its capabilities. Notably, the demonstration trajectory program was developed by Elizabeth Snyder and Betty Jean Jennings, though Herman and Adele Goldstine were credited for it. The machine was formally dedicated the following day at the University of Pennsylvania . Regrettably, none of the women who programmed the machine or created the demonstration were invited to the formal dedication or the subsequent celebratory dinner.

The initial contract for ENIAC stipulated a cost of $61,700, but the final expenditure ballooned to nearly $500,000 (approximately $9,000,000 in 2024). The U.S. Army Ordnance Corps formally accepted the machine in July 1946. ENIAC was temporarily shut down on November 9, 1946, for a period of refurbishment and memory upgrade. It was then transferred to Aberdeen Proving Ground in Maryland in 1947. On July 29, 1947, it was reactivated and operated continuously until 11:45 p.m. on October 2, 1955, when it was retired in favor of the more efficient EDVAC and ORDVAC computers.

Role in the Development of EDVAC

In the summer of 1946, a few months after ENIAC’s public debut, the Pentagon initiated “an extraordinary effort to jump-start research in the field” by inviting leading figures in electronics and mathematics from both the United States and Great Britain to a series of forty-eight lectures in Philadelphia. These lectures, collectively known as The Theory and Techniques for Design of Digital Computers, but more commonly referred to as the Moore School Lectures , featured ENIAC’s inventors delivering half of the presentations.

ENIAC’s design was unique and was never replicated. The design freeze imposed in 1943 meant that it omitted certain innovations that rapidly gained prominence, most notably the ability to store a program within the machine’s memory. Eckert and Mauchly, recognizing these limitations, began work on a new design, eventually named EDVAC , which aimed to be both simpler and more powerful. A key innovation was Eckert’s 1944 description of a memory unit utilizing mercury delay lines , capable of storing both data and program instructions. John von Neumann, who was consulting for the Moore School on the EDVAC, participated in the meetings where the stored-program concept was elaborated. Von Neumann subsequently drafted a preliminary document, First Draft of a Report on the EDVAC , intended as an internal memorandum. This report, which formalized and expanded upon the ideas discussed in the meetings, was distributed by ENIAC administrator and security officer Herman Goldstine to various government and educational institutions. This dissemination sparked widespread interest in the construction of a new generation of electronic computing machines, including the Electronic Delay Storage Automatic Calculator (EDSAC) at Cambridge University, England, and the SEAC at the U.S. Bureau of Standards.

Improvements

Over its operational lifespan, ENIAC underwent several significant improvements. A rudimentary read-only stored programming mechanism was implemented using the function tables as program ROM . This innovation, developed in various forms by Richard Clippinger’s group and the Goldstines, was subsequently incorporated into the ENIAC patent. Clippinger collaborated with von Neumann on the design of the instruction set for this new system. Clippinger favored a three-address architecture, while von Neumann proposed a simpler one-address architecture for ease of implementation. In this modified system, three digits of accumulator #6 served as the program counter, accumulator #15 functioned as the main accumulator, accumulator #8 acted as an address pointer for accessing data from the function tables, and most of the remaining accumulators (1–5, 7, 9–14, 17–19) were repurposed for data memory.

In March 1948, a converter unit was installed, enabling programming directly from standard IBM cards via the reader. The “first production run” utilizing these new coding techniques was applied to the Monte Carlo problem in April. Following ENIAC’s relocation to Aberdeen, a register panel was constructed for memory expansion, though it proved to be non-functional. A small master control unit was also added to facilitate the machine’s power-up and shut-down sequences.

The programming of the stored program for ENIAC was undertaken by Betty Jennings, Clippinger, Adele Goldstine, and others. It was first demonstrated as a stored-program computer in April 1948, executing a program designed by Adele Goldstine for John von Neumann. This modification, while reducing ENIAC’s speed by a factor of six and eliminating its parallel computation capabilities, was deemed a worthwhile trade-off for the significant reduction in reprogramming time, from days to mere hours. Furthermore, analyses had indicated that due to the disparity between the electronic speed of computation and the electromechanical speed of input/output operations, most real-world problems were inherently I/O bound , even without leveraging the machine’s original parallelism. The computational bottleneck would likely remain I/O-bound even after the speed reduction.

In early 1952, a high-speed shifter was incorporated, enhancing shifting operations by a factor of five. July 1953 saw the addition of a 100-word core memory expansion, utilizing binary-coded decimal and excess-3 number representations. To support this expanded memory, ENIAC was equipped with a new Function Table selector, a memory address selector, pulse-shaping circuits, and three new orders were integrated into the programming mechanism.

Comparison with Other Early Computers

While mechanical computing devices have a history stretching back to Archimedes (and the remarkable Antikythera mechanism ), the 1930s and 1940s are widely recognized as the dawn of the modern computer era.

ENIAC, much like the IBM Harvard Mark I and the German Z3 , possessed the ability to execute an arbitrary sequence of mathematical operations, yet it did not read instructions from a tape. Similar to the British Colossus , its programming involved manipulation of plugboards and switches. ENIAC’s unique distinction lay in its fusion of full, Turing-complete programmability with the raw speed of electronic components. The Atanasoff–Berry Computer (ABC), ENIAC, and Colossus all employed thermionic valves (vacuum tubes) . However, ENIAC’s registers operated using decimal arithmetic, a contrast to the binary arithmetic employed by the Z3, the ABC, and Colossus.

Like Colossus, ENIAC required physical rewiring for reprogramming until April 1948. In June 1948, the Manchester Baby executed its first program, earning the title of the first electronic stored-program computer . Although the concept of a stored-program computer with unified memory for both data and instructions was conceived during ENIAC’s development, it was not initially implemented in ENIAC. This was primarily due to wartime exigencies that prioritized rapid completion, and ENIAC’s limited 20 storage locations would have been insufficient to accommodate both data and programs.

Public Knowledge

The Z3 and Colossus were developed independently during World War II, separate from the ABC and ENIAC. Work on the ABC at Iowa State University ceased in 1942 when John Atanasoff was called to Washington, D.C. for physics research with the U.S. Navy, and the machine was subsequently dismantled. The Z3 met its end in 1943, destroyed during Allied bombing raids on Berlin. The ten Colossus machines, integral to the UK’s war effort, remained secret until the late 1970s, although knowledge of their capabilities was shared among their UK staff and select American visitors. ENIAC, in stark contrast, was demonstrated to the press in 1946, “and captured the world’s imagination.” Consequently, older historical accounts of computing may lack a comprehensive understanding of this pivotal period. All but two of the Colossus machines were dismantled in 1945; the remaining pair were employed by GCHQ to decrypt Soviet messages until the 1960s. The public demonstration of ENIAC was meticulously prepared by Snyder and Jennings, who devised a program capable of calculating a missile’s trajectory in a mere 15 seconds—a task that would have taken a human computer several weeks to complete.

Patent

For a confluence of reasons, including Mauchly’s examination of the Atanasoff–Berry computer (ABC) in June 1941, which had been prototyped in 1939 by John Atanasoff and Clifford Berry , U.S. patent 3,120,606 for ENIAC, filed in 1947 and granted in 1964, was ultimately invalidated. This occurred in 1973 following the landmark federal court case Honeywell, Inc. v. Sperry Rand Corp. . The court’s decision established that the ENIAC inventors had derived the fundamental concepts of the electronic digital computer from Atanasoff, legally recognized Atanasoff as the inventor of the first electronic digital computer, and placed the invention of the electronic digital computer into the public domain .

Main Parts

ENIAC was comprised of approximately 40 main panels and three portable function tables, designated A, B, and C. The physical arrangement of these panels followed a systematic layout, forming the walls of the machine:

Left Wall

• Initiating Unit
• Cycling Unit
• Master Programmer – panels 1 and 2
• Function Table 1 – panels 1 and 2
• Accumulator 1
• Accumulator 2
• Divider and Square Rooter
• Accumulator 3
• Accumulator 4
• Accumulator 5
• Accumulator 6
• Accumulator 7
• Accumulator 8
• Accumulator 9

Back Wall

• Accumulator 10
• High-speed Multiplier – panels 1, 2, and 3
• Accumulator 11
• Accumulator 12
• Accumulator 13
• Accumulator 14

Right Wall

• Accumulator 15
• Accumulator 16
• Accumulator 17
• Accumulator 18
• Function Table 2 – panels 1 and 2
• Function Table 3 – panels 1 and 2
• Accumulator 19
• Accumulator 20
• Constant Transmitter – panels 1, 2, and 3
• Printer – panels 1, 2, and 3

An IBM card reader was connected to Constant Transmitter panel 3, and an IBM card punch was integrated with Printer Panel 2. The Portable Function Tables (A, B, and C) could be interfaced with Function Table 1, 2, and 3.

Parts on Display

Fragments of the monumental ENIAC are preserved and displayed across various institutions, serving as tangible links to the dawn of the digital age:

• The School of Engineering and Applied Science at the University of Pennsylvania houses four of the original forty panels (Accumulator #18, Constant Transmitter Panel 2, Master Programmer Panel 2, and the Cycling Unit) along with Function Table B.
• The Smithsonian , specifically the National Museum of American History in Washington, D.C., possesses five panels, including accumulators, constant transmitter components, a divider/square rooter, function table and printer elements, and an initiating unit.
• The Science Museum in London exhibits a receiver unit from ENIAC.
• The Computer History Museum in Mountain View, California, displays three panels (Accumulator #12, Function Table 2 panel 2, and Printer Panel 3) and portable function table C.
• The University of Michigan in Ann Arbor holds four panels, including two accumulators and components of the high-speed multiplier and master programmer, salvaged by Arthur Burks .
• The United States Army Ordnance Museum at Aberdeen Proving Ground , Maryland , where ENIAC was extensively used, is home to Portable Function Table A.
• The U.S. Army Field Artillery Museum in Fort Sill , as of October 2014, acquired seven ENIAC panels, including accumulators #7, #8, #11, and #17, along with panels connected to function table #1, and a rear panel showcasing its vacuum tubes. A module of tubes is also on display.
• The United States Military Academy at West Point, New York, possesses one of ENIAC’s data entry terminals.
• The Heinz Nixdorf Museum in Paderborn, Germany, exhibits three panels (Printer panel 2 and a High-speed Function Table) and has undertaken the reconstruction of an accumulator panel, capturing the essence of the original machine in a simplified form.

Recognition

ENIAC was honored as an IEEE Milestone in 1987, acknowledging its profound impact on technological advancement.

In 1996, coinciding with ENIAC’s 50th anniversary, the University of Pennsylvania launched the “ENIAC-on-a-Chip” project. This ambitious endeavor resulted in the creation of a minuscule silicon computer chip , measuring just 7.44 mm by 5.29 mm, which replicated ENIAC’s functionality. While this 20 MHz chip operated at speeds vastly exceeding ENIAC’s, it represented only a fraction of the performance of contemporary microprocessors of the late 1990s.

The year 1997 saw the induction of the six women who had performed the majority of ENIAC’s programming into the Women in Technology International Hall of Fame . Their crucial role was further highlighted in documentaries such as LeAnn Erickson’s 2010 film, Top Secret Rosies: The Female “Computers” of WWII , and Kate McMahon’s 2014 short, The Computers, which emerged from Kathryn Kleiman’s two decades of research for the ENIAC Programmers Project. In 2022, Grand Central Publishing released Kleiman’s book, Proving Ground, a detailed account of the six ENIAC programmers and their monumental task of translating complex diagrams and electronic schematics into functional programs.

In 2011, Philadelphia, in commemoration of the 65th anniversary of ENIAC’s unveiling, officially declared February 15 as ENIAC Day. The machine’s 70th anniversary was marked on February 15, 2016.