DEC Hebrew Character Set: History and Technical Specifications
In the early era of computing, standardizing how different languages were represented digitally was a significant challenge. The DEC Hebrew character set was developed by the Digital Equipment Corporation (DEC) to solve this for the Hebrew alphabet, providing a structured way to encode Hebrew letters within an 8-bit framework.
Technical Foundations
The DEC Hebrew set is classified as an Extended ASCII encoding. It was built upon the foundation of the DEC Multinational Character Set (MCS), which served as a precursor to the widely used ISO/IEC 8859-1 standard. To accommodate the Hebrew alphabet, DEC modified the MCS by removing existing definitions from code points 192 to 223 and 224 to 250.
The Hebrew letters were then integrated by replacing code points 251 to 256. This specific range mirrors the Hebrew range found in its 7-bit counterpart, but with the high bit set to indicate an 8-bit value.
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Relationship with Modern Standards
Because of its lineage from the MCS, the DEC Hebrew character set shares significant similarities with later standards. Specifically, it is closely related to ISO/IEC 8859-8 and Windows code page 1255.
These similarities are most evident in two areas: many characters in the range 160 to 191 remain identical across these sets, and the Hebrew letters are consistently positioned between code points 192 and 250 in all three encoding systems.
| Attribute | Detail |
|---|---|
| Developer | Digital Equipment Corporation (DEC) |
| Classification | Extended ASCII |
| Base Standard | DEC MCS |
| Transform/Encode | SI 960 |
| Successor | ISO/IEC 8859-8 |
Key Facts
- Developed by Digital Equipment Corporation (DEC) to support the Hebrew alphabet.
- Based on the DEC Multinational Character Set (MCS).
- Utilizes an 8-bit encoding structure.
- Replaced code points 251 to 256 with Hebrew letters.
- Shares character ranges (160-191 and 192-250) with ISO/IEC 8859-8 and Windows-1255.
- Was succeeded by the ISO/IEC 8859-8 standard.
Frequently Asked Questions
What is the DEC Hebrew character set?
It is an 8-bit Extended ASCII character set created by Digital Equipment Corporation to enable the digital representation of the Hebrew alphabet.
How does it differ from the DEC MCS?
It was derived from the DEC Multinational Character Set (MCS) by removing definitions from code points 192-223 and 224-250, and replacing code points 251-256 with Hebrew letters.
Which modern standards are similar to DEC Hebrew?
It is very similar to ISO/IEC 8859-8 and Windows code page 1255, particularly in the character ranges 160-191 and 192-250.
What replaced the DEC Hebrew character set?
The DEC Hebrew character set was succeeded by the ISO/IEC 8859-8 standard.
What is the relationship between DEC Hebrew and 7-bit encoding?
The range used for Hebrew letters corresponds to the Hebrew range of its 7-bit counterpart, but it utilizes the high bit to function as an 8-bit set.