Higher Level Languages
Higher Level Languages
Should programming a computer cost more than buying the computer?
Until the mid 1950s, programming digital computers meant creating instructions in the language of the machine itself—a slow, error-prone process. As computers grew more affordable, programming costs began to overshadow hardware costs.
The development of higher-level, more user-friendly programming languages made writing large programs easier. But the cost of creating software was—and is—still huge.
Flowcharting template
Early programmers drew charts by hand to design the logical flow of a program.
View Artifact DetailFORTRAN infograph automatic reference manual
FORTRAN or assembly code was first written on coding sheets and then punched into cards or paper tapes that were read into the computer.
View Artifact DetailTech Talk: Moving Beyond Machine Language
As stored in the computer's memory, a program is just a pattern of zeros and ones that encodes a sequence of instructions in the computer's “machine language.” But writing that sequence is tedious and error-prone.
The earliest advance in programming was to create an "assembly language" so that people could write names instead of numbers, both for the operation codes and for the identification of memory locations. The "assembler" program translates that into machine language. But, generally speaking, the programmer still had to write one line in the program for every computer instruction.
The next breakthrough, in higher-level languages like Fortran, was to create a "compiler" program that would translate a more English-like statement into as many machine-language instructions as needed to perform the function.
Language designers have created hundreds of higher-level languages, used by programmers to write millions of programs.
Programming example
Suppose yo were told to write a program to compute the sum of one thousand numbers stored in computer memory. Here are program fragments for three different ways you might have done it in 1960 for the IBM 7090 computer.
View Artifact DetailIBM blank coding forms - Flowcharting Worksheet, Diagramming and Charting Worksheet
Early programmers drew charts by hand to design the logical flow of a program.
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