[GreenKeys] Selectric I/O

[Edward Greeley]

Hi Keith,

Happy New Year and all that...

Yep, I remember the Selectric-based terminals. I was a member of a 
computer club in Rome, NY in the early to mid '80s and ran afoul of 
those things. Seems that a club member had found a source of the things 
at a surplus/salvage place in Phila., PA and sicced a bunch of us onto 
them. I think there were a couple dozen or more of the machines living 
with club members. Problem was - they were EBCDIC coded jobs. Don't 
remember the brand. What to do with them?

Well, at the time, I was the editor of the club newsletter and since I 
was constantly preaching to the members that I needed SOMETHING to put 
in the thing, someone said "somebody" ought to write up a conversion for 
the Selectrics. I was elected. I had found an article in a previous 
KB/Microcomputing or Byte mag that I used for the basis of "our" 
conversion. IIRC, the reference article had a source for the necessary 
electronics interface, but had nothing about how to un-EBCDIC the 
things. Had to buy (not cheap!) the IBM maint. and parts manuals for the 
basic Selectric then figure out how to change them back to "normal 
correspondence" configuration. Turned out that no major parts were 
required, but a rather major disassembly of the code bars for the 
selector mechanism that positions the ball for each character WAS 
required. What a PITA! We also had to acquire type balls to replace the 
EBCDIC ones. That was not cheap either. Sorta amazing how similar the 
Selectric selector mechanism was to TTY selectors.

End result was that we wound up with a group of 
converted-deconverted-reconverted Selectrics that could be used as 
conventional off-line typewriters and as on-line ASCII computer 
terminals. I think a cheap dot matrix printer could be had for a bit 
less money, but a Diablo Hy-Type or A-J (also a Selectric conversion, 
IIRC) letter-quality machine was a LOT more money.

Ironic that you should ask about this as it's just been in the last two 
or three months that I finally threw away my record copies of the club 
newsletters after all these years. My conversion article was in there. 
Never fails: Dump something, THEN you want it again. I may still have it 
on a CP/M - Wordstar floppy, but have nothing to read CP/M disks any more...

Ed Greeley


Keith Densmore wrote:
> Power to the Green in 2011,
> 
> I came across an interesting old advertisement on Ebay for   a IBM Selectric 
> Terminal. This unit was put together by a company called Data-Trans and was 
> a 300 baud printing terminal.
> The ad is here
> 190361445421
> 
> Any list members have, use,  or even know of the existence of any of these 
> old terminals? I know IBM had several versions of Selectric Teminals over 
> the years but most used non standard codes. But it might be possible to do a 
> data conversion with some modern electronics.  It would be cool to see one 
> running with HeavyMetal. Just trying to dream up more weird projects for the 
> new year.
> 
> 73,
> Keith ve3ts 
>