In 1975, IBM announced the IBM Electronic Selectric Composer. This Composer
had the ability to store about 5000 characters of typing in its memory. It had
a main storage area and an alternate storage area, allowing the operator to
work on two different documents. When a new document needed to be typeset, the
operator would clear out one of the two memory banks in order to enter a new
document. The machine had two power switches, one that controlled the memory
and one that controlled the typewriter/printer portion. If you turned off the
memory switch, or unplugged the machine, say goodbye to your documents.
This machine was a dramatic improvement over the original IBM Composer. The
typist no longer was required to type the documents twice, rather they could
set the appropriate settings first, type the document, then have the Electronic
Composer retype the document justified as specified.
Click here to watch a short movie showing it justifying some text.