Re: [unrev-II] Field report: Twiddler chord keyboard

From: Paul Fernhout (
Date: Mon Mar 27 2000 - 17:42:37 PST

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    From: Paul Fernhout <>

    Eric Armstrong wrote:
    > How is it for doing ctrl+key and alt+key sequences?

    There a six thumb buttons in the back. One is fot CTRL and one is for
    ALT. So these keys are easy to enter. Control ALT is probably more
    difficult. I'm not sure it works.

    > From your description, it seems that the device would be
    > best for doing letter-commands in conjunction with the
    > mouse, and small edits where the amount of text is very
    > limited.

    > That can be A-ok for a lot of work. For example, browsing
    > emails. When authoring a response, though, it would seem
    > to make sense to grab the keyboard.

    True. However, it does exercise a different set of muscles if you use it
    in your non dominant hand, so there may be some general value to
    potentially useing it to reduce RSI.

    On comparing it to guitar use and ergonomics:

    I've since found an alternate key mapping someone made which is
    optimized for letter usage in English and minimizing finger stress.
    For example, with this alternative system, all sequences involve finger
    presses in the same column (which is easier). However, I haven't tried
    to learn this alternative.

    I've noticed that the switches are awkwardly installed. In short, only
    one side of them really goes down (like a lever pivoting on the other
    side). They are arranged so that the middle two rows have the area to
    push next to each other, and the outer rows are pushablwe to the
    outside. It would be best if the pushable area for each row was on the
    same side. I think this is why the switches seem hard to push in various
    situations. If you press them straight on in the middle this isn't as

    Working with the Pilot:

    I did get the cable built to hook it the twiddler to the Pilot and it
    works. Unfortunately, it rapidly drains the pilot battery - in part
    because it countinuously send position updates the Pilot doesn't need --
    preventing the pilot from "dozing" which is what it normally does most
    of the time even when the screen is on to save power. It drained about
    1/2 the battery in about an hour of use. So I'm not sure this can be
    practically used with the pilot. To create such a system and have it
    have maximum battery life probably would require electroinc changes to
    the twiddler and Palm device. Note -- this level of power use isn't an
    issue for running it with a wearable pentium or such since they have
    much higher baseline power draw.

    Data gloves:

    Even before I bought the twidler I remembered hearing about the glove
    idea like what was mentioned by Jim Morrissett and thought of building
    one. That seems most ideal -- something that just recognizes gestures or
    finger taps. Unfortunately, there are none for sale that I know of (and
    probably not for $200 yet.) I even though of making one where you
    chorder simply by pressing the tips of fingers to the thumb -- a simple
    electrical contact being at the end of each finger. You could enter
    4X4=16 choices on each two handed closure, and so two sets of choices
    would be 16X16 = 256 choices. You could get fancier with using different
    positions on the sides of fingers or palm or differentiating between
    input from one hand, the other, or both at once. Making such gloves
    would be almost trivial (just wire to foil patches sewn on gloves),
    although one would need a PIC or Forth chip to debounce the contacts and
    convert the sequences to serial port input.

    -Paul Fernhout
    Kurtz-Fernhout Software
    Developers of custom software and educational simulations
    Creators of the Garden with Insight(TM) garden simulator

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