A 1973 IBM Selectric typeball recorded dancers' body movements

A 1973 IBM Selectric typeball recorded dancers' body movements(ibm.com)

62 points by KC8ZKF 5 years ago | 23 comments

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

jaclaz 5 years ago |

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

rbanffy 5 years ago | |

The distant future of 1980...

lisper 5 years ago |

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

Stratoscope 5 years ago | |

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.

hondo77 5 years ago | |

http://dancenotation.org/lnbasics/frame0.html

myself248 5 years ago | |

There are TONS of videos about it, but I'm not finding what I was hoping for, which is an example of a dance "subtitled" with Labanotation.

ctdonath 5 years ago | |

I expected a downloadable font file reproducing it. Want to show my dancer daughter.

Avshalom 5 years ago | |

https://en.m.wikipedia.org/wiki/Labanotation

ncmncm 5 years ago | |

Big question: is it in standard Unicode?

tgv 5 years ago |

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

analog31 5 years ago | |

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 5 years ago |

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

dieselerator 5 years ago |

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 5 years ago | |

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

anonymfus 5 years ago |

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

Animats 5 years ago | |

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

seltzered_ 5 years ago |

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 5 years ago | |

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 5 years ago |

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 5 years ago |

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

https://www.worldcat.org/title/instruction-manual-for-use-wi...

gorgoiler 5 years ago |

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 5 years ago |

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