A Selectric printer...

Paul Berger phb.hfx at gmail.com
Mon Nov 23 09:54:37 CST 2015

That look like one of the original selectric I/Os which means that 
mechanically it is very much like the standard Office Products (OP) 
selectric.  The sound that it is making when running suggests that the 
motor belt is cracked or is missing teeth. Unlike the OP selectric  the 
IO used a more powerful capacitor start motor that was capable of 
ripping the teeth of the belt if the mechanism was jammed.   It looks 
like the dust covers are missing there should be covers over the cycle 
shaft and op shaft.

When you types it looks like the carriage did not move and also you 
noted that carriage return does not work,  This may be due to the 
"cords" being broken or off the drums.  There should be two white nylon 
cords, one attached to each side of the carrier, the one on the left 
goes around behind the frame an wraps onto a drum there, the drum for 
the one on the right should be visible when you look inside.  The 
visible drum has a bevel gear on the face that meshes with two bevel 
gears on the op shaft. That look like they have springs around them.  
There should be a nylon shoe that presses against the on one the left 
when you press the carriage return key.

I found this online which may be of some help to you, 

This manual will at least help with the mechanical part of the IO.  The 
cover latches are on either side and will be half buried in the likely 
now rotten foam on the sides.  They have a slot in the top you can stick 
the blade of a screwdriver into and move the top of the latch towards 
the front.

The original IO used 48V solenoids  to operate the mechanism as a 
printer.  There will be 6 for selection, one for shift, one for cycle 
clutch, and one for each function, likely tab, carriage return and line 
feed.  The basic operation is the selection magnets are picked to pull 
the desired latches and then the cycle clutch magnet is pulsed to take a 
print cycle. To maximize the print speed, the selection magnets get 
picked as the cycle clutch passes the rest position that way the cycle 
clutch never latches up to give you maximum print speed. This is timed 
by contacts operated by cams at the left end of the cycle shaft.    
There will also be a block of contacts under the selection assembly that 
are used to detect what key is pressed and in some versions of the 2970s 
( there are lots) there was a set of contacts designed to verify that 
the correct character was printed.  The ones I worked on most where 
teller terminals used in banks and they had these check contacts.  There 
is also shift feedback contact and a contact that is call the long 
function contact that is activated during tabs and carriage return.

Other things I found that may be helpful:


Training videos, These appear to be the original slide and audio tape 
training for the OP selectric.


I don't recall there being any specific manuals for for the IO, but I 
was working on these daily and did not need to refer to manuals often.


On 2015-11-23 4:50 AM, Mike Ross wrote:
> Just the typewriter. Western I/O evidently threw away all the IBM
> electronics and took just the basic I/O Selectric mechanism, and
> installed their own electronics in the base.
> Video here, some pics in comments:
> https://www.facebook.com/tmfdmike/videos/10207930350486487/?l=4583813823466285768
> Mike
> On Mon, Nov 23, 2015 at 3:46 AM, Paul Berger <phb.hfx at gmail.com> wrote:
>> On 2015-11-22 9:20 AM, Mike Ross wrote:
>>> I have an I/O Selectric device which is badged as, and was originally, an
>>> IBM 2970 Reservation Terminal.
>>> For better or worse, it was one of those bought up in the late 1970s by a
>>> company called 'Western I/O", based out of Scottsdale Arizona. They
>>> converted them for home use. One version used a Motorola 6800 to make a
>>> nifty-sounding terminal with selectable baud rates etc. I appear to have
>>> the 'other' version; a cheap and nasty printer-only conversion with some
>>> form of parallel port.
>>> Anybody else got one? Docs about them? Parts? Schematics? I'd like to get
>>> hold of one of the 'proper' terminal conversion versions... Must be some
>>> squirreled away in garages!
>>> Alternatively, any doc on the original 2970? There's an incredible dearth
>>> of information about what we're once very common devices...
>> Did you get the whole machine typewriter and control unit or just the
>> typewriter?  If you got the control unit the manuals may be inside.  The
>> typewriter part of it is just a modified office selectric with solenoids to
>> do the selection and operate the functions and then a whole bunch of open
>> strap contacts for feedback and also to sense what is typed on the keyboard.
>> One of the first problems you may encounter is the motor belt is likely
>> rotten and would be a challenge to change if you have never been inside a
>> selectric, especially with all the extra stuff hung off it on an I/O.  The
>> reservation terminals I worked on nearly 40 years ago where connected to a
>> telegraph line. 75 baud with about a 150V DC swing.  Pictures?
>> Paul.

More information about the cctech mailing list