I learned the Twiddler 2 default key map in about an afternoon.
Several things were clear to me by the end of the day. My pinky and
ring fingers were sore, mostly my pinky. The ordering of the letters
made them easier to learn by virtue of not having to refer back to the
manual so frequently. Learning the symbols was very difficult. I did
not retain any, in fact. My back was much more relaxed than if I had
been typing. Putting my thumb in the position suggested by the manual
was a lose. Instead holding the Twiddler like the neck of a guitar,
with the strap over my knuckles, gave the needed stability. This
stability leaves when using the thumb keys. Using the mouse required
gripping the Twiddler with my fingers and contorting my thumb.
Finally, the extra inch and a half of Velcro strap was clumsy.
Also by the end of the first day, the DEL key had broken. Despite
daily reassurances from Chris George (my salesman), it took Handykey a
week to ship me a new one. This gave me plenty of time to come up
with a new key map.
I use the Twiddler 2 in my left hand. My hands seem larger than
everyone else's (my index finger is approximately 8.5cm). I will be
typing primarily English text and C programs into emacs. I expect to
use completion mode extensively.
The most obvious primary factor in chord map design is letter
frequency. Theories here differ. The following order has been used
successfully in cryptanalysis.
etnrioasdhlcfpumygwvbxkqjz
These can be grouped statistically as follows.
e t nrioa s d hlcfpum ygwv bxkqjz
These frequency equivalences describe which letters can be swapped to
make their positions easier to remember, or to make frequent letter
combinations faster.
No frequency data could be found for symbols, so I analyzed all files
in my home directory to come up with the following order. Adjustments
were made to account for symbols inserted automatically by emacs,
especially the hundreds of asterisks and pound signs used as comment
leaders. Given the relative infrequency of symbols to letters, I also
took liberties in grouping similar symbols.
,.?!;:-/\'"`()<>[]{}_=+$ *|#@&%~^
The whole trick then is balancing the cognitive harmony -- putting
open parenthesis next to close parenthesis, for example -- with haptic
harmony -- using the pinky as little as possible, for example. The
default key map has excellent cognitive harmony, since all of the
letters are in order. On the other hand, the only haptic harmony is
that e is easy to type.
Having SPACE, BACKSPACE, and ENTER mapped to single keys in the left
column seems like good cognitive harmony to bring over from the
default keymap. Putting TAB there would be useful, since I plan to
make TAB the global completion key. I guess I use these keys in that
order of frequency. Already then we have the following mappings:
L000 = SPACE
0L00 = BKSP
00L0 = ENTER
000L = TAB
Worn at the most comfortable angle, my fingers most easily press
columns M, L, and R, in that order. My index and middle fingers are
much easier to use than my ring and pinky, and my ring finger is much
easier to use than my pinky. Fewer keys makes a chord somewhat
easier, although a single key chord in the pinky row is harder than a
two key chord on the index and middle rows. Chords where adjacent
fingers press on the same row are easiest. Chords where adjacent
fingers press on non-adjacent rows are very difficult, especially
between my ring and pinky. The most difficult chords then are LRLR
and RLRL.
Equipped with these partial orderings I laid out the letter chords as
follows.
0 M000 = e
0 0M00 = t
0 R000 = n
0 0R00 = r
0 MM00 = i
0 LL00 = o
0 RR00 = a
0 ML00 = s
0 MR00 = d
0 LM00 = h
0 RM00 = l
0 00M0 = c
0 00R0 = f
0 M0M0 = p
0 L0L0 = u
0 R0R0 = m
0 M0L0 = y
0 M0R0 = g
0 L0M0 = w
The Design Of A Twiddler Keymap
by Joe Miklojcik
0 R0M0 = v
The Design Of A Twiddler Keymap
by Joe Miklojcik
0 000M = b
0 000R = x
0 L0R0 = k
0 R0L0 = q
0 LR00 = j
0 RL00 = z
The arrow keys need good cognitive harmony, and the default key map gives
this, although 90 degrees off. Although I don't like using my pinky for
down arrow, any alternatives I could come up with seemed worse.
0 0MM0 = UPAR
0 0M0M = DNAR
0 0MR0 = LTAR
0 0ML0 = RTAR
The symbols are typed so rarely, I used as much cognitive harmony as
possible in laying them out.
0 L00L = .
0 L00M = ;
0 L00R = \
0 M00L = ?
0 M00M = ,
0 M00R = !
0 R00L = /
0 R00M = :
0 R00R = -
0 0LL0 = (
0 0LM0 = _
0 0LR0 = )
0 0L0L = [
0 0L0M = +
0 0L0R = ]
0 LLL0 = <
0 LLM0 = =
0 LLR0 = >
0 LL0L = {
0 LL0M = $
0 LL0R = }
0 0RM0 = |
0 0RR0 = *
0 0R0M = &
0 0R0R = @
0 RRR0 = %
0 RRM0 = ~
0 RR0R = ^
0 RR0M = #
Here is the map I pasted to the side of my laptop display.
en
tr
cf
bx
L
ohj
uwk
.;\
M
sid
ypg
?,!
R
zla
qvm
/:-
0
L
(_)
[+]
L
L
<=>
{$}
R
|*
&@
R
R
&%
#^
Reprogramming the Twiddler took about two hours. The auto-chord
feature is excellent. Each letter must be programmed in both upper
and lower case. The lack of programmability in the CTRL and ALT keys
disappoints me. That none of the thumb keys sends a scan code is
similarly boggling.
Walking around with a Twiddler in your hand makes you look a little
strange. Walking around with a black plastic wedge emblazoned with
the "twiddler 2" logo makes you look like you walked out of the Woody
Allen movie featuring the building I work in. Frankly, I am willing
to look like a freak, but not an advertisement for freakishness.
Applying a small amount of acetone to the logo erased it, but also
marred the finish. Perhaps a dilution would work better. That the
keys themselves are legended seems pointless, since in any natural
position you can't see them. I plan to eventually remove all such
markings.
The trackpoint has ideal friction with the thumb. It also gets dirty
easily. There is no obvious way to clean it.
Instead of trimming the Velcro strap, I put additional hook Velcro
near the bottom of the L row side. This will be very uncomfortable if
I ever switch the Twiddler to my right hand.
(jfm3)
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