In computing, output padding is the insertion of non-printing characters into the device output stream to allow for a preceding control operation to take effect.
Output padding was necessary on many printing devices, notably Teletype and other mechanical terminals, after the issuance of a carriage return.[1] Without the padding, following characters might print in the middle of the output line.
Output padding was also necessary on many display terminals after cursor positioning, scrolling, and other commands.[2][3]
Typically the null character was used; the delete character was occasionally used. The number of padding characters depended on the particular device, but also sometimes on the horizontal position of the printing carriage.
Notes
- ^ Pooch, Udo W. (1991). Telecommunications and Networking. CRC Press. p. 431. ISBN 978-1-351-09400-9.
- ^ Free Software Foundation (November 7, 1998). "Padding". The Termcap Library. Retrieved 2024-01-13.
- ^ Golden, V. Ellen (April 14, 1981). "An Introduction to ITS for the MACSYMA User". Mathlab Memo (3): 40.