Murray keyboard perforator model No. 5-PM, complete with operator's console and paper holder, made by Reid Brothers, Engineers, Limited, Camden, England, 1914-1916.
Donald Murray of New Zealand (1865-1945) modified the Baudot multiplex system by introducing a keyboard perforator which encoded each letter in a five-unit code. In the Baudot system each of several keyboards was connected direct to line, meaning that the operators had to maintain a strict rhythym to keep in step with each other, causing mental strain. The paper tape output of the Murray keyboard was instead fed to a transmitter unit via a loop which provided slack in the tape so that each operator could maintain his own rhythm without affecting the others. As well as relieving the stress, higher keying speeds of from 30 to 45 words per minute were possible.