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EDIT
BS BS, or backspace, was used on Teletypes and on later printing terminals to position the printhead for overstriking the previous character. Uses for this function include underlining with the Underscore character, putting diacritics on letters, and making APL overstrike characters.
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EDIT
Back Space (Ctrl-H) Move the Cursor one character to the left
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History On teletype equipment, this control code moved the print head one character position to the left. Obviously the character was not erased.
On paper tape punches, this control code backed the tape up to the previous character position. It was usually used in combination with DEL to delete a character. |
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Modern Usage This character generally moves the cursor one character to the left. Usually the character under the new cursor position is deleted (and possibly the text following it moved left to fill in the gap), while other times the character is left undisturbed. This is referred to as destructive and non-destructive back space, respectively.
On most machines, the Backspace key generates a BS, although on a few machines the DEL or Delete key generates a BS. On character printers the backspace simply moves the printer head back one character position. This allows characters to be printed on top of each other. In Graphical User Interfaces, Ctrl+H is generally a shortcut for the find and replace editing action. |
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Suggested Implementation In video terminal applications, a BS should move the cursor one character to the left, placing a space in the position moved to. The host system can be expected to handle any other changes to the screen.
In text editors, a BS should delete the character to the left of the cursor, moving all subsequent text as necessary. In printing applications, a BS should move the print position one character to the left, unless already at the beginning of a line. Any character subsequently printed will overprint any characters already printed at the new position. |
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ADD NEWSIMILAR CHARACTERS
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