In the beginning, because the ENIAC was classified, the women were only allowed to work with blueprints and wiring diagrams in order to program it. During her time working on ENIAC, she had many productive ideas at night-time, leading other programmers to jokingly state that she "solved more problems in her sleep than other people did awake." The ENIAC was unveiled on February 15, 1946, at the
University of Pennsylvania. It cost around $487,000, . She was one of those who wrote the first generative programming system (
SORT/MERGE). Holberton used a deck of playing cards to develop the decision tree for the binary sort function, and wrote the code to employ a group of ten tape drives to read and write data as needed during the process. She wrote the first statistical analysis package, which was used for the
1950 US Census. In 1953 she was made a supervisor of advanced programming in a part of the Navy's Applied Math lab in
Maryland, where she stayed until 1966. set for
BINAC, which is considered to be the prototype of all modern programming languages. She also participated in the development of early standards for the
COBOL and
FORTRAN programming languages with
Grace Hopper. Later, as an employee of the
National Bureau of Standards, she was very active in the first two revisions of the Fortran language standard ("FORTRAN 77" and "Fortran 90"). ==Death==