Definition
Windows-1256, also designated as CP1256, is an 8-bit single-byte character encoding designed by Microsoft to represent Arabic script and related languages in the Windows operating system.
Overview
Introduced in the mid‑1990s, Windows-1256 is part of the Windows code page family and serves as the default Arabic encoding for legacy Windows applications. It maps the first 128 code points (0–127) to the same characters as ASCII, while the upper half (128–255) provides glyphs for Arabic letters, Arabic presentation forms, and a limited set of additional symbols needed for Persian, Urdu, and other languages that use the Arabic script. The encoding is superseded in many contexts by Unicode (particularly UTF‑8), but it remains supported for backward compatibility with older software and data files.
Etymology/Origin
The name “Windows-1256” follows Microsoft’s convention for naming code pages: the prefix “Windows” denotes its association with the Windows operating system, and the number “1256” identifies the specific code page within the Windows-125x series, which includes other regional encodings such as Windows‑1252 (Western European) and Windows‑1251 (Cyrillic). The numeral was assigned sequentially as new code pages were defined.
Characteristics
- Byte Structure: Single-byte (8 bits) per character, allowing a maximum of 256 distinct symbols.
- ASCII Compatibility: Code points 0x00–0x7F are identical to the standard US‑ASCII set.
- Arabic Letter Mapping: Includes the basic Arabic alphabet (U+0600–U+06FF range) and selected presentation forms.
- Language Support: Primarily Arabic, with additional characters for Persian (e.g., U+06AF, U+06CC) and Urdu.
- Control Codes: Retains Windows‑specific control characters (e.g., 0x0D for carriage return).
- Compatibility: Recognized by Windows API functions (e.g.,
MultiByteToWideChar), web browsers, and many email clients when declared with the charset “windows-1256”. - Limitations: Lacks full coverage of all Arabic script characters and diacritics found in Unicode; cannot represent bidirectional text layout rules beyond basic character ordering.
Related Topics
- Unicode (UTF‑8, UTF‑16) – Modern universal encoding standards that replace legacy code pages for Arabic and other scripts.
- Code page 1256 (CP1256) – Alternate designation for Windows‑1256 used in technical documentation.
- Arabic script – The writing system for which the encoding provides character representations.
- ISO/IEC 8859-6 – An earlier 8-bit Arabic encoding standard, often compared with Windows‑1256.
- Bidirectional Algorithm – The algorithm defined by Unicode for correctly displaying mixed left‑to‑right and right‑to‑left text, relevant when converting between Windows‑1256 and Unicode.