
148
Practical aids
to programming
Fourier transforms For conversions between time and frequency
domains.
Sorting Subroutines for putting arrays into order.
Input and output Decimal-binary conversion, display, and
reading numbers from keyboards.
Filing functions Software needed to use the filing systems.
Peripheral
control Interface software for supporting cassette
tapes,
floppy disks, synchronous and asyn-
chronous data transmission.
Operating
systems General-purpose systems for controlling
interrupts and ensuring timely response to
external events.
System tests Programs that test the system and generate
warnings if errors are detected.
The