The Friden Flexowriter was the first real word-processor, an electric typewriter able to record and play back typed text. The Flexo-writer, as it was originally known, was a mature product by 1947, able to record the text of a letter on punched paper tape and play it back with pauses to allow a typist to insert custom text such as addresses, salutaitons and amounts owed.
The Flexowriter was developed by a sequence of different companies, including IBM, but it came to its maturity under the Commerical Controls Corporation in the 1940s. Friden (the calculator company) purchased CCC in the 1950s and was, in turn, purchased by Singer in 1965.
The Model 2201 Programmatic Flexowriter described here was built after the Singer purchase, so it represents a mature machine, far more streamlined in styling than the machines of the 1950s. This machine was originally used by either UniBank or an associated collection agency in Coralville Iowa, and is equipped with a Model 2314/3 Selectadata auxiliary paper-tape reader so that it can perform an entirely automatic mail-merge function, combining the text of a form letter read from one paper-tape reader with successive mailing addresses and custom content from a second reader. All of the required logic is done with relays operating at power-line voltage.
Several others have web pages that focus on the Flexowriter to sone extent: