In computer hardware, a word mark or flag is a bit in each memory location on some
variable word length computer
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word si ...
s (e.g.,
IBM 1401
The IBM 1401 is a variable-wordlength decimal computer that was announced by IBM on October 5, 1959. The first member of the highly successful IBM 1400 series, it was aimed at replacing unit record equipment for processing data stored on pu ...
,
1410
Year 1410 ( MCDX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.
Events
January–December
* March 25 – The first of the Yongle Emperor's campaigns against the Mongols is ...
,
1620
Events
January–June
* February 4 – Prince Bethlen Gabor signs a peace treaty with Ferdinand II, Holy Roman Emperor.
* May 17 – The first merry-go-round is seen at a fair (Philippapolis, Turkey).
* June 3 – ...
) used to mark the end of a
word
A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no conse ...
. Sometimes the actual bit used as a word mark on a given machine is not called ''word mark'', but has a different name (e.g., ''flag'' on the IBM 1620, because on this machine it is multipurpose).
The term ''word mark'' should not be confused with
group mark or with
record mark, which are distinct characters.
References
{{Reflist, 30em
Computing terminology
Early computers