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 [EMAIL PROTECTED] _______________________________________________ Edu-sig mailing list [email protected] http://mail.python.org/mailman/listinfo/edu-sig
