Friden Flexowriter SFD

UvA Computer Museum catalogue nr 93.43


photo taken with an Apple Quicktake camera, 1996

This Friden Flexowriter, model SFD, was used with the early Electrologica X1 and X8 computers. Though it was improbably heavy and made the noise of a machine gun, it had about the same functionality as the well-known Teletype ASR33 teleprinter. But at least by X1/X8 customers, it was never used on-line. Rather the user would carry his prepared lengths of paper tape on bicycle to the computer centre vice versa.
The Flexowriter, originally a pre_WWII IBM development, was manufactured in Nijmegen, The Netherlands, from (about) 1955 to 1965.

There were appreciable differences between the papertape coding schemes used by the various Flexowriter models. None of them was ASCII-compliant.
Many paper tapes carrying Algol-60 programming are still around, in attics of their originators, or in archives. We can still read these tapes on a standard optical reader.

We have prepared a program for translating the resulting byte stream either into Flexowriter glyphs or into an ASCII representation, suitable as input to the MARST Algol-60 to C translator (by the lack of Algol-60 compilers for contemporary hardware).

Our Flexowriter has been used at the Anton Pannekoek Institute for Astronomy, University of Amsterdam. It has been in working condition until 2016, when an irreplaceable driving belt was broken.
The Flexowriter's user manual (8 MB pdf) is available for download.
rev April, 2017