[GreenKeys] DURA Selectric ASR terminals free

Robert Nickels ranickel at comcast.net
Mon Dec 16 11:04:39 EST 2019


Back in the 70s, I envied my buddy's Selectric printer that he'd built 
an IEEE-488 interface to in order to drive it from a 4051 graphics 
terminal he build the "one piece at a time" way when he worked for 
Tektronix.   Since I didn't need that complexity I came up with a 
minimalist interface to my Z-80 home computer.   I bought a surplus IO 
Selectric that had been used to print airline reservations and stripped 
everything out back to the seven tilt and rotate solenoids.   The 
hardest part was filling the empty holes in the enclosure with Bondo 
;-)    If I remember correctly I had to latch some bits to be able to 
drive things like the spacebar and carriage return, but the whole thing 
only required a few ICs plus driver transistors and was connected by an 
8 bit parallel port.   Of course everything was done with timing loops 
so it was slow - the mechanism was spec'ed at 14.8 characters per second 
and I think I tweaked mine up to run 11 or so, but it worked great and 
could still be used as a typewriter.

It was really cool to have true letter quality print in the day when 
everyone was using Epson dot-matrix printers.   Then I got a Diablo 
daisywheel printer and the thrill was gone ;-)    But nowadays an 
Arduino would do the job easily and the manual is here:  
http://media.ibm1130.org/E0033.pdf

73, Bob W9RAN



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