Simultaneous Peripheral Operation On-Line
<operating system, history> (SPOOL) Accessing peripheral devices with the
help of an off-line tape drive. The term was derived by IBM for use with the IBM
360 operating systems.
In the early days of computing (early 1960s), before multitasking was invented,
computers (e.g. IBM 704) could run only one job at a time. As peripheral devices
such as printers or card readers were much slower than the CPU, devoting the
computer (the only computer in many cases) to controlling such devices was
impractical.
To free the CPU for useful work, the output was sent to a magnetic tape drive,
which was much faster than a printer and much cheaper than a computer. After the
job was finished the tape was removed from the tape drive attached to the
computer and mounted on a tape drive connected to a printer (such as the IBM
1403). The printer could then print the data without holding up the computer.
Similarly, instead of inputting the program from the card reader it was first
copied to a tape and the tape was read by the computer.
(1999-01-12)
Nearby terms:
Simulation Language for Alternative Modeling «
Simulation Oriented Language « Simultaneous
Engineering Environment «
Simultaneous Peripheral Operation On-Line »
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