The default chordset of the SpiffChorder, referred to as the modified NASA set in its source code and documentation, is based on one developed for Infogrip's BAT Personal Keyboard in the mid-1980s (a joint project with the United States National Aeronautics and Space Administration). The patent for their CHORDIC KEYBOARD SYSTEM was filed with the US Patent Office in 1992, but it has since expired and is currently in the public domain. According to the patent application, the most frequently used primary symbols are mapped into the chords which are the easiest and most efficient to use. (It continues to go into much greater detail on the testing methodology and analysis used to determine this correlation, for those who are interested.)

Since I spend most of my time in a text terminal, I put together a chord chart for the SpiffChorder which fits safely into a standard 80x24 character screen (I made it 78x22 to allow for a one-character border on all sides). I also left four empty entries to accommodate custom macros.

 +----------+---F-N-CN+   +----------+---F-N-CN+   +----------+------F>CF----+
 | -RMI -C- | a A +   |   | PR-- --- | u U ""  |   | P--- --F | ret  kp ret  |
 | P--I --- | b B \ | |   | PR-- -C- | v V ] } |   | ---- --F | lshf kp +    |
 | --M- -C- | c C 7 & |   | P--- --- | w W 5 % |   | PRMI --F | caps kp ins  |
 | --MI --- | d D / ? |   | P--I -C- | x X &   |   | -R-I --F | tab  kp -    |
 | -RMI --- | e E = + |   | -R-- --- | y Y 4 $ |   | --M- --F | bksp kp beg  |
 | P--- -C- | f F 9 ( |   | PR-I --- | z Z ` ~ |   | -RM- --F | del  kp del  |
 | -R-- -C- | g G 8 * |   | ---- -C- | spc 1 ! |   | P-MI --F | sclk kp /    |
 | -RM- --- | h H 00  |   | PR-- N-- | ; :     |   | P-M- --F | ptsc kp *    |
 | ---I --- | i I 2 @ |   | --M- N-- | , <     |   | -R-- --F | rght kp rght |
 | -R-I -C- | j J ()  |   | -RM- N-- | . >     |   | PR-- --F | down kp down |
 | -R-I --- | k K $   |   | -RMI N-- | ' "     |   | PRM- --F | pgdn kp pgdn |
 | ---I -C- | l L 6 ^ |   | P--- N-- | fnc     |   | ---I --F | left kp left |
 | --MI -C- | m M *   |   | -R-- N-- | esc     |   | --MI --F | up   kp up   |
 | PRM- -C- | n N [ { |   | PRM- N-- | lal ral |   | -RMI --F | pgup kp pgup |
 | PRMI -C- | o O 0 ) |   | P--I N-- | ins     |   | PR-I --F | home kp home |
 | -RM- -C- | p P %   |   | PR-I N-- | lct rct |   | P--I --F | end  kp end  |
 | PR-I -C- | q Q ?   |   | PRMI N-- | nml     |   |          |              |
 | --M- --- | r R 3 # |   | PRMI NC- | num     |   |          |              |
 | PRM- --- | s S - _ |   | ---- N-F | brk     |   |          |              |
 | PRMI --- | t T 000 |   | ---- NCF | rst     |   |          |              |
 +----------+---------+   +----------+---------+   +----------+--------------+

back to The Man-Machine...