[Edu-sig] Learning (some more) programming

[Scott David Daniels]

Paul D. Fernhout wrote:
> Now, to go on the offensive here, Doug Engelbert and others clearly showed 
> even in the late 1960s and early 1970s  that a set up with a chord 
> keyboard in one hand and a mouse in the other is much father than a full 
> keyboard and a mouse when using a typical computer application.
>    http://en.wikipedia.org/wiki/Chord_keyset

I quite doubt this.  The "clearly showed" may be true for editing
(mark-up and movement tasks), but as I recall the Augment group was
quite frustrated that a fast typist could beat even a well-practiced
chord-pad and mouser.  The Referenced article claims w/o citation that
"Engelbart proved that trained typists, after just a few hours of
training, could perform more efficiently using a chord keyboard than
a conventional QWERTY keyboard."  From what I recall, this was not
true for text entry, but was for commands and short phrases.  It was
the movement back and forth between the keyboard and mouse that killed
the skilled typist, not the letter entry speed.

The article is suspect, because it claims the chord-pad had 31=2**5-1
distinct chords, but really, it was 30=2**5-2; 0-0-0-0-0 (all up) cannot
be entered, and 1-1-1-1-1 was reserved for "cancel that chord, I typo'ed
(much as DEL was an over punch to erase a mistaken byte).  If you used
the mouse buttons with the chord-pad (which I think you did), you had
access to 126=2**7-2 or 254=2**8-2 chords if you kept one mouse button
out of the chord, enough for all of ASCII (Note the NUL and DEL would
still be out, but old paper-tape rules dictated special uses for those
characters as well).

-- Scott David Daniels
Scott.Daniels at Acm.Org