
A 1973 IBM Selectric typeball recorded dancers' body movements - KC8ZKF
https://www.ibm.com/blogs/industries/selectric-typewriter-dancers/
======
Stratoscope
Very interesting article, and not just about the dance notation typeball.

The 1962 print ad says "Potential speed becomes practical speed, thanks to a
stroke storage system that releases type characters in sequence no matter how
fast the typing."

I got curious about the "stroke storage system" \- was it mechanical,
electronic, or what?

The Wikipedia page has an explanation of this mechanical storage:

> The machine had a feature called "Stroke Storage" that prevented two keys
> from being depressed simultaneously. When a key was depressed, an
> interposer, beneath the keylever, was pushed down into a slotted tube full
> of small metal balls (called the "compensator tube") and spring latched.
> These balls were adjusted to have enough horizontal space for only one
> interposer to enter at a time. (Mechanisms much like this were used in
> keyboards for teleprinters before World War II.) If a typist pressed two
> keys simultaneously both interposers were blocked from entering the tube.
> Pressing two keys several milliseconds apart allows the first interposer to
> enter the tube, tripping a clutch which rotated a fluted shaft driving the
> interposer horizontally and out of the tube. The powered horizontal motion
> of the interposer selected the appropriate rotate and tilt of the printhead
> for character selection, but also made way for the second interposer to
> enter the tube some milliseconds later, well before the first character had
> been printed. While a full print cycle was 65 milliseconds this filtering
> and storage feature allowed the typist to depress keys in a more random
> fashion and still print the characters in the sequence entered.

[https://en.wikipedia.org/wiki/IBM_Selectric_typewriter](https://en.wikipedia.org/wiki/IBM_Selectric_typewriter)

------
jaclaz
The sad thing is that I actually vaguely remember them in the office and that
earlier, as a kid, few things were cooler than the TV UFO series:

SHADO

SUPREME HEADQUARTERS ......

ALIEN DEFENCE ORGANIZATION ...

SECRET LOCATION .... BENEATH FILM STUDIO

[https://www.youtube.com/watch?v=ya_9fUNstvc](https://www.youtube.com/watch?v=ya_9fUNstvc)

~~~
rbanffy
The distant future of 1980...

------
lisper
An entire article about dance notation and not a single example of what the
notation looks like. Disappointing.

~~~
Stratoscope
There is an example in the corner of the picture of the dancer leaping over a
typeball. But yeah, it is just a small example and there is no explanation of
what the symbols mean.

------
tgv
I typed my first article on a Selectric using a normal and a math type ball.
There was a lot of switching involved.

~~~
analog31
Amusingly, there was an early "scientific" word processor for the IBM PC, that
simulated the Selectric math ball. You pressed one of the extra keys (maybe
"alt" but I don't remember) and got the alternative ball. You could also move
up and down by half lines. It was very quick to type math.

I used it for my dissertation. The page numbering feature could not be adapted
to my university's requirements, so I printed out my manuscript without page
numbers, and pasted them in by hand, then had the whole thing photocopied.

------
wiseleo
Labanotation is very interesting as a tech-savvy choreographer. I am looking
at taking it to the next level with Unreal. :)

For those interested in dance transcription, there is a formerly commercial
but now freeware Windows product called Danceforms.
[http://www.charactermotion.com/df-
download.html](http://www.charactermotion.com/df-download.html)

------
dieselerator
That is interesting.

I have an IBM Selectric that I purchased at a thrift store. It is a marvel
engineering. It was too much to resist. I have not used it, but I tried it
out. It works. It really is a fine machine. I think I will spin it up and
exercise it.

I wonder if one of those dance type balls is available any where. I suppose
not, but it would be fun to try it out.

~~~
chiph
One of the interesting things about the Selectric is that it contains a
mechanical digital-to-analog converter .. a Whiffletree mechanism.

[https://www.youtube.com/watch?v=bRCNenhcvpw](https://www.youtube.com/watch?v=bRCNenhcvpw)

------
anonymfus
I am surprised that Labanotation and other dance notations still are not in
Unicode.

~~~
Animats
It's not a good match to a font model. It's putting stretchable symbols on
tracks, like musical notation. There's no simple string equivalent.

Labanotation to animation has been done.[1]

[1]
[http://www.sfu.ca/~tom/Papers/LabanDancer1.pdf](http://www.sfu.ca/~tom/Papers/LabanDancer1.pdf)

------
seltzered_
I'd love to know if labanotation has actually been effective in dance. It
might work for choreographed works, but I feel like it might fail for a newer
person relying on it over practice.

Any social dancers on HN?

~~~
wiseleo
Yes, it works great and not difficult to read. There are limitations, mostly
because of symbol overload when expressing more complex movement. Ballet is
simple to read because ballet consists of mostly well-defined upright
movement. Modern dance, of which ballet is a subset, has a lot of floor work.
That becomes difficult to express.

There's one source of truth, Ann Guest, and some people are frustrated at not
getting the most precise answers.

The system encompasses the entire body up to fingertips.

------
jacquesm
Amazing mechanics, there is a lot to learn by just examining the mechanism of
these. As a kid I had access to one, my mom had one at home. I distinctly
remember how fast the ball moved because I got a nice 'J' imprint on my pinkie
trying to see what would happen. That hurt (predictable). That taught me not
to mess with live machinery and to have respect for things that move faster
than you can follow with your eyes.

------
adrianmonk
Some libraries seem to have copies of the instruction manual (not online,
though):

[https://www.worldcat.org/title/instruction-manual-for-use-
wi...](https://www.worldcat.org/title/instruction-manual-for-use-with-the-
labanotation-ibm-selectric-typewriter-element/oclc/6230205)

------
gorgoiler
It’s still amazing that a printing element with this radius could achieve
accurate character registration.

I remember the type all’s being such a part of pop culture that a televised
game show, involving contestants identifying objects in a black bag by touch
alone, were expected to identify a typeball as a _common, everyday object_.

------
tsuru
I think these are the typewriters in the loud open office scene(s) at the
Daily Planet in the movie "Superman (1978)"

