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A typical statement in FORTRAN looks very like the underlying mathemat-
ical equation. Thus
ye xx
=− +
sin
2
became
( ) ( )
y
=
EXP
F X
SIN
F XX
+
**2
Because of this simplicity and how closely it resembles the language of mathe-
matics, FORTRAN rapidly became the dominant language for scientific comput-
ing. Backus's team had come very close to meeting their design goal:
Fig. 3.7. The irst FORTRAN topic
from IBM.
In practice the FORTRAN system produced programs that were 90% as good
as those written by hand, as measured by the memory they occupied or
the time they took to run. It was a phenomenal aid to the productivity of
a programmer. Programs that had taken days or weeks to write and get
working could now be completed in hours or days. 12
FORTRAN also produced another great benefit - the portability of programs
across different machines. Although the first compiler was written for the
IBM 704, very soon there were FORTRAN compilers for other IBM computers.
Competing computer manufacturers also soon produced FORTRAN compilers
for their machines. For the first time there were computers capable of speaking
the same language so that programmers did not have to learn a new language
for every new computer.
In 1961, Daniel McCracken published the first FORTRAN programming
textbook for use in undergraduate courses in universities. In 1966, FORTRAN
became the first programming language to be formally standardized by ANSI,
the American National Standards Institute, the organization that creates stan-
dards for the U.S. computer industry ( Fig. 3.7 ). The FORTRAN language, now
written Fortran with only one capital letter, has evolved with time to incorpo-
rate new structures and technologies from research on programming languages
by computer scientists. It is nevertheless surprising that Fortran programs are
still much used in scientific computing more than fifty years after the first
introduction of the language.
The other major breakthrough in early computer programming was a
language for business applications. After her work on MATH-MATIC, Hopper
turned to the problem of making business programming - the tasks needed to
run a business such as managing accounting and inventory - easier and more
intelligible to that community. By the end of 1956, she had produced a com-
piler for FLOW-MATIC, a language that contained around twenty English-like
expressions and allowed the use of long character names ( Fig. 3.8 ). For exam-
ple, to test whether the value of variable A is greater than that of variable B, in
Fortran we would write:
Fig. 3.8. FLOW-MATIC, developed by
Grace Hopper in 1956, was the first
programming language that allowed
users to describe operations in English-
like expressions.
Fig. 3.9. COBOL, one of the first
programming languages, is still alive
and well. Much business transaction
software is written in COBOL and there
are about 200 billion lines of code in use.
Ninety percent of financial transactions
are written in COBOL.
IF A.GT. B
By contrast, in a language like FLOW-MATIC, one would write a similar com-
parison test as:
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