The term "coding" can refer to a number of different things in relation to computers.
In the early days of digital computing, it meant creating a program in the instruction set (machine language) of the computer running the program. Often, this involved determining the values of the bits required in each of the fields of the instruction, and capturing the set of instructions in a form that could be entered into the computer (switch settings, paper tape or punch-card hole patterns, or the like) and executed.
These days, it means writing a program in any language that can be compiled to a form that can be executed by the computer. In the case of interpreted languages, the compiled form is actually data for a program that runs on the computer. It is not machine code, nor does it bear any likeness to machine code.
Besides coding of instructions, coding can refer to the representation of numbers in a computer. A convenient form for representation often is determined by the hardware used for arithmetic. A variety of signed number representations have been used. Two's complement is perhaps the preferred representation today for integers, and the IEEE 754 standard (or its international equivalent) defines coding for floating point numbers.
Coding can also refer to the mapping of bit patterns to characters or other input/output signals or artifacts. EBCDIC and ASCII are two methods of mapping text and control characters to computer bit patterns. These days, Unicode serves a similar purpose. Audio signals can be encoded in a variety of ways, including you-law and A-law as well as straight linear binary coding (often 2's complement).
One of the early uses of digital computers was for the purpose of breaking ciphers (codes) used in wartime. Coding takes on a whole different meaning in that context.
In the early days of digital computing, it meant creating a program in the instruction set (machine language) of the computer running the program. Often, this involved determining the values of the bits required in each of the fields of the instruction, and capturing the set of instructions in a form that could be entered into the computer (switch settings, paper tape or punch-card hole patterns, or the like) and executed.
These days, it means writing a program in any language that can be compiled to a form that can be executed by the computer. In the case of interpreted languages, the compiled form is actually data for a program that runs on the computer. It is not machine code, nor does it bear any likeness to machine code.
Besides coding of instructions, coding can refer to the representation of numbers in a computer. A convenient form for representation often is determined by the hardware used for arithmetic. A variety of signed number representations have been used. Two's complement is perhaps the preferred representation today for integers, and the IEEE 754 standard (or its international equivalent) defines coding for floating point numbers.
Coding can also refer to the mapping of bit patterns to characters or other input/output signals or artifacts. EBCDIC and ASCII are two methods of mapping text and control characters to computer bit patterns. These days, Unicode serves a similar purpose. Audio signals can be encoded in a variety of ways, including you-law and A-law as well as straight linear binary coding (often 2's complement).
One of the early uses of digital computers was for the purpose of breaking ciphers (codes) used in wartime. Coding takes on a whole different meaning in that context.
