I've been working on an IBM Selectric typewriter
which I bought earlier
in the year. It is the I/O Selectric type 735 which differs from a
normal Selectric in having the solenoids and switches on it to allow it
to be used as a printer and keyboard.
When I got it the motor wouldn't run, and the mechanism was jammed. The
motor problem was its thermal trip, which is meant to be the resettable
type, so I replaced that. I gave the whole thing a clean with
degreaser, which freed up the mechanicals, then oiled and greased it. It
then worked happily as a typewriter.
I have made a small interface, based on an Arduino Mega 2560, which
provides a serial port. Currently this only supports printing, but will
be extended to include the keyboard. It uses almost all the digital I/O
on the Mega (15 solenoids, 27 contacts.)
There are still some adjustments to be done, and I am awaiting a set of
Bristol Wrenches (Keys) so I can safely do these. I have tried using
Torx and Allen keys, and while they can be made to 'fit', it doesn't
seem like a good idea.
There are some pictures and videos of the typewriter here:
http://www.flickr.com/photos/ljw/sets/72157632841492802/
You can get the Arduino interface code here:
https://github.com/ibm2030/IOSelectric
I haven't yet documented the hardware I used for the solenoid drivers,
but if anyone is interested I can put some notes together (basically:
Arduino output to 2N7000 FET buffer to ITS4140N +48V high-side driver on
the output side, and a simple 250R pullup to +5V on the input side.)
Manuals here:
http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/typewriter/selectric/
(or other Bitsavers mirrors)
Info on the Mega2560 here:
http://arduino.cc/en/Main/arduinoBoardMega2560
Wow! What a beast. It's no wonder they commanded such a high price back
in the day. Matter of fact, I think a good portion of the selectrics
were leased if I remember correctly. Very nice looking machine, even
without the cover. :)
--
Dave Land
Land Computer Service
Check out my site at