ASCII 8 — BS

Backspace (BS) moves the cursor one position backward, historically enabling overprinting on mechanical terminals. Generated by Ctrl+H, the Backspace key on modern keyboards sends either BS (ASCII 8) or DEL (ASCII 127) depending on terminal configuration — a notorious source of confusion for developers. In Unix systems, the 'stty erase' command determines which character acts as the erase key. The distinction between destructive backspace (erasing a character) and non-destructive backspace (just moving the cursor) still causes compatibility issues.

Control characters were defined in the original 1963 ASCII standard to manage telecommunications equipment and terminal devices. Unlike printable characters representing visible symbols, control codes perform actions: initiating transmissions, acknowledging received data, triggering device alerts, and structuring information hierarchically. Of ASCII's 128 code points, 33 are designated as control characters (codes 0–31 plus 127), reflecting the standard's deep roots in telegraphy and serial communication systems. While most control codes have fallen out of daily use, several remain essential to modern computing workflows.

In the ASCII encoding table, Backspace is assigned code point 8 in decimal (0x08 hexadecimal, 010 octal, 00001000 binary). The 7-bit ASCII standard, first published in 1963 by the American Standards Association, defines exactly 128 characters that remain the foundation of text encoding systems worldwide. UTF-8, the dominant encoding on the modern web, is fully backward compatible with ASCII — every ASCII character is encoded as the identical single byte in UTF-8, guaranteeing that Backspace works reliably across all operating systems, programming languages, and internet protocols.