Editing Baudot code (section)

===Murray code===
[[File:Baudot Tape.JPG|thumb|240px|upright|Paper tape with holes representing the "Baudot–Murray Code". Note the fully punched columns of "Delete/Letters select" codes at end of the message (on the right) which were used to cut the band easily between distinct messages. The last symbols before the fully punched columns at the end are BRASIL CR LF CR FS (word Brasil, carriage return, line feed, carriage return, shift to figures)]]
In 1901, Baudot's code was modified by [[Donald Murray (inventor)|Donald Murray]] (1865–1945), prompted by his development of a typewriter-like keyboard. The Murray system employed an intermediate step: an operator used a keyboard perforator to punch a paper tape and then a transmitter to send the message from the [[punched tape]]. At the receiving end of the line, a printing mechanism would print on a paper tape, and/or a reperforator would make a perforated copy of the message.<ref>{{cite journal |last=Foster |first=Maximilian |date=August 1901 |title=A Successful Printing Telegraph |journal=[[World's Work|The World's Work: A History of Our Time]] |volume=II |pages=1195–1199 |url=https://books.google.com/books?id=IF6tNZnhO7wC&pg=PA1195 |access-date=2009-07-09 }}</ref>

Because there was no longer a connection between the operator's hand movement and the bits transmitted, there was no concern about arranging the code to minimize operator fatigue. Instead, Murray designed the code to minimize wear on the machinery by assigning the code combinations with the fewest punched holes to the most [[letter frequencies|frequently used characters]].<ref>{{Harvnb|Copeland|2006|p=38}}</ref><ref>{{cite book |title=Telegraph and Telephone Age |url=https://books.google.com/books?id=TFUiAQAAMAAJ|year=1921 |quote=I allocated the most frequently used letters in English language to the signals represented by the fewest holes in the perforated tape, and so on in proportion.}}</ref> For example, the one-hole letters are E and T. The ten two-hole letters are AOINSHRDLZ, very similar to the "[[Etaoin shrdlu]]" order used in [[Linotype machine]]s. Ten more letters, BCGFJMPUWY, have three holes each, and the four-hole letters are VXKQ.

The Murray code also introduced what became known as "format affectors" or "[[control character]]s"{{snd}} the [[Carriage return|CR]] (Carriage Return) and [[Newline|LF]] (Line Feed) codes. A few of Baudot's codes moved to the positions where they have stayed ever since: the NULL or BLANK and the DEL code. NULL/BLANK was used as an idle code for when no messages were being sent, but the same code was used to encode the space separation between words. Sequences of DEL codes (fully punched columns) were used at start or end of messages or between them which made it easier to separate distinct messages. (BELL codes could be inserted in those sequences to signal to the remote operator that a new message was coming or that transmission of a message was terminated).

Early [[Creed & Company|British Creed]] machines also used the Murray system.