Diff — Fran Bilas

{{infobox

| title = Fran Bilas

| image = fran-bilas-punchcards.png

| caption = Bilas at ENIAC's punch-card reader, c. 1946. U.S. Army photograph, public domain.

| born = Frances V. Bilas · March 2, 1922 · Philadelphia, Pennsylvania, U.S.

| died = July 18, 2012 (aged 90)

| other_names = Frances Bilas Spence · Fran Spence

| education = Chestnut Hill College — B.S. mathematics, minor in physics, 1942 · Temple University (mathematics graduate study)

| career = U.S. Army firing-table corps, Moore School (1942–45) · ENIAC programmer (1945–47)

| spouse = Homer W. Spence (m. 1947)

| children = 3

| known_for = One of the six original ENIAC programmers · credited with the machine's first sort routine and its program-check mechanisms · operator of the February 1946 public demonstration

| awards = Women in Technology International Hall of Fame (1997, with the ENIAC six)

}}

**Frances V. Spence** (née **Bilas**; March 2, 1922 – July 18, 2012), known professionally as **Fran Bilas**, was an American mathematician, physicist, and computer scientist — one of the six original programmers of [[ENIAC]], the first general-purpose electronic digital computer, and therefore one of the first computer programmers in history.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]][[cite: Haigh, Priestley & Rope, [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (MIT Press, 2016)]]

Within the six, Bilas's documented contributions are unusually easy to map onto the modern profession: she is credited with authoring ENIAC's first **sort routine** and constructing the machine's **program-check mechanisms** — systematic procedures for verifying that a run was behaving correctly — and was one of the operators of the machine at its public unveiling in February 1946, when the first public photographs of programming-in-progress were made.[[cite: Haigh, Priestley & Rope, [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]][[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

# Early life and education

Frances V. Bilas was born in Philadelphia, Pennsylvania, the second of five sisters. Both of her parents worked in education — her father as an engineer for the Philadelphia Public School system, her mother as a teacher — a household in which schooling was treated as the family business.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022), biographical material on Bilas]]

She attended the **South Philadelphia High School for Girls**, graduating in January 1938, and began university study at **Temple University**. When Chestnut Hill College awarded her a full scholarship she transferred there, majoring in **mathematics** with a minor in **physics** — a combination that placed her among the small number of American women then receiving serious technical training. She graduated in 1942. Among her Chestnut Hill classmates was a fellow mathematics major named [[Kay McNulty|Kathleen McNulty]]; the two would meet again on the most consequential project of their lives.[[cite: Chestnut Hill College records; Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

She later returned to Temple for graduate work in mathematics.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

# The firing-table corps

Bilas entered the workforce in the middle of the Second World War, into the one technical occupation then open to women with her training: the United States Army's human-computer corps at the University of Pennsylvania's **Moore School of Electrical Engineering**. The corps — several dozen women officially titled "**computers**" — produced artillery firing tables for the Army's Ballistic Research Laboratory, computing trajectories on Monroe desk calculators and, when available, on the Moore School's differential analyzer. The work was mathematically demanding and operationally relentless: a single table represented hours to days of continuous computation, and the Army needed them in volume.[[cite: Evans, [*Broad Band*](https://www.penguinrandomhouse.com/books/545427/broad-band-by-claire-l-evans/) (2018); Haigh et al., [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]]

Like most of the corps, Bilas found the labor as monotonous as it was essential. What the position provided — and what no classroom could — was daily practice in decomposing a physical problem into a fixed sequence of elementary arithmetic operations: the precise mental discipline that would shortly be called programming.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

# ENIAC

## Selection and the absence of any method

In 1945 the Army circulated a call for six volunteers to staff a classified machine under construction at the Moore School. Bilas volunteered and was selected, together with [[Kay McNulty]], [[Betty Jennings]], [[Betty Snyder]], [[Marlyn Wescoff]], and [[Ruth Lichterman]] — the group subsequently known as the **ENIAC six**, and in hindsight as the first programmers.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

The machine, **ENIAC** (Electronic Numerical Integrator and Computer), was electronic but not programmable in any modern sense. It had no stored instruction set, no programming language, and no documentation; a computation was realized by physically configuring the hardware — routing signals between units through plugboards with hundreds of patch cables, setting thousands of switches, and sequencing the machine's twenty accumulators into a plan of execution. The six were initially furnished only with the engineers' block diagrams, from which they reconstructed the machine's logical behavior before being admitted to the room where it stood. The techniques they developed under these conditions — planning computations on paper by flowchart, tracking machine state systematically, and verifying configurations before committing to them — constitute the earliest recorded practice of programming as a distinct discipline.[[cite: Haigh, Priestley & Rope, [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]]

## Sort routines and program checks

Within the team, two of Bilas's specific contributions are documented in the historical record and deserve emphasis because they map directly onto practices that remain central to the field.

The first is ENIAC's **initial sort routine**. Ordering data is among the most basic requirements of computation — firing tables, inventory, and analysis all reduce to it — and Bilas is credited with authoring the first program on the machine to perform it — effectively the first sorting algorithm executed on a general-purpose electronic computer. (The record needs a caveat here: Betty Snyder Holberton is also widely described as inventing the first sort routine, referring to her later Sort–Merge Generator work on UNIVAC; Bilas's claim is the earlier one, on ENIAC itself.)[[cite: Haigh, Priestley & Rope, [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]]

The second, and arguably more consequential, is her construction of the machine's **program-check mechanisms**. ENIAC was physically unreliable in ways modern hardware is not: vacuum tubes failed on a cycle measured in days, marginal connections drifted, and a malformed signal produced not a crash but confidently incorrect output. Kleiman's research credits Bilas with devising systematic checks — procedures interleaved with a run to confirm that intermediate state remained correct and to localize the fault when it did not. In contemporary terms this is the ancestral form of runtime validation, automated testing, and fault isolation; on ENIAC it was simply how a computation became trustworthy enough to be believed.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022); [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]]

[[File:two-women-eniac.jpg|Betty Jennings (left) and Frances Bilas (right) operating ENIAC's main control panel, c. 1946 — the most widely reproduced image of the ENIAC six at work. U.S. Army photograph, public domain.]]

## The February 1946 demonstration

On February 14–15, 1946, the Army presented ENIAC to the press — the first public disclosure that a fully electronic general-purpose computer existed. The demonstration's centerpiece was a sixty-second artillery trajectory computed in less time than the shell would have required to fly it. Bilas served as one of the machine's operators for the event, and it is her face — with Betty Jennings at the main control panel — that appears in the era's most frequently reproduced photographs.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022); contemporary press coverage of the unveiling]]

The coverage itself recorded the era's misreading: the women at the panels were variously cropped from photographs, omitted from captions, or described to reporters as decorative staff. The machine's hardware designers, Eckert and Mauchly, were named; its programmers were not.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

Bilas continued to work on ENIAC after the war's end, as the machine's programming work moved with it to the **Ballistic Research Laboratory at Aberdeen Proving Ground, Maryland**.[[cite: Haigh, Priestley & Rope, [*ENIAC in Action*](https://mitpress.mit.edu/9780262535175/eniac-in-action/) (2016)]]

# Marriage and leaving the field

In 1947 she married **Homer W. Spence**, an enlisted Army engineer assigned to the ENIAC group at the Moore School, who moved with the machine to Aberdeen and later became head of its Computer Research Branch. She left government employment shortly after the marriage — in a period when women in federal service routinely exited technical posts upon marrying — and began raising a family; the Spences had three sons, Joseph, Richard, and William.[[cite: Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

Her programming career ended with the resignation. The commercial era of the profession she had helped create — the **Eckert–Mauchly Computer Corporation**, which produced **BINAC** and then [[UNIVAC_I|UNIVAC]], the first commercial computer in the United States — went forward with her colleagues Betty Jennings and Betty Snyder, but Spence never returned to full-time work in computing. In later decades she lived largely outside the field's public view, a pattern shared by most of the six, whose contributions were substantially forgotten by the industry they had founded.[[cite: Evans, [*Broad Band*](https://www.penguinrandomhouse.com/books/545427/broad-band-by-claire-l-evans/) (2018); Kleiman, [*Proving Ground*](https://www.hachettebookgroup.com/titles/kathy-kleiman/proving-ground/9781538718285/) (2022)]]

# Recognition and death

Institutional recognition arrived half a century late. In **1997** the six ENIAC programmers were inducted collectively into the **Women in Technology International Hall of Fame** — the first major acknowledgment that programming's founding generation was female. Bilas lived to see the historical correction gather pace, as Kathy Kleiman's research, her book *Proving Ground* (2022), and her documentary *The Computers* (2014) restored the six to the record under their own names.[[cite: WITI Hall of Fame, 1997 inductees; Kleiman, [*The Computers*](https://www.kathykleiman.com/documentary) (2014)]]

Frances Bilas Spence died on July 18, 2012, at the age of ninety. She is buried at the Cemetery of the Holy Rood in Westbury, New York.[[cite: Obituary record, Frances B. Spence, 2012]]

[[File:reprogramming-eniac.jpg|Reprogramming ENIAC: a new problem meant physically rewiring the machine's patch panels — the task Bilas and her colleagues systematized into the discipline now called programming. U.S. Army photograph, public domain.]]

# Assessment

Bilas's historical position rests on two facts that no longer require argument. First, she was present at the creation: the ENIAC six invented programming practice in the absence of any precedent for it. Second, her own documented work — the sort routine and program checks credited to her — addressed the two questions every working programmer still answers daily: *how do I make the machine transform the data,* and *how do I prove it did so correctly.* The second question, largely her specialty, is the field's least celebrated discipline and its most essential one. That a monument to testing should belong to a woman whose own work was for decades untested by history is a symmetry the record has only recently begun to correct.

# See also

- [[The first programmers]] — the story of all six

- [[Kay McNulty]] · [[Betty Jennings]] · [[Betty Snyder]] · [[Marlyn Wescoff]] · [[Ruth Lichterman]] — the other five

- [[UNIVAC I]] — the commercial successor her colleagues helped program

- [[History of Programming]]

- [[JoAnn H. Morgan]] — the woman who followed them into the launch room, a generation later

# References

6. U.S. Army photographs of ENIAC and its operators, 1945–46 (public domain).

[[Category:History]]

[[Category:People]]