Abstract: A method of generating symbols from a chording keyboard is described. A unique feature of this method is accepting a sequence of chords from the keyboard without either an intervening chord or a requirement that all keys be released between chords. Another unique feature is that that the chord map is independent of chords before or after a particular chord, for a particular symbol. That is, a user need only memorize one chord for each symbol, and then may transition directly from exactly that chord to any other chord. There are no special transition requirements. The number of keys on a keyboard for this method may be 4 to 10, inclusive. Such a keyboard may be operated with one hand. Specific attributes of embodiments or chord tables are described.

Abstract: A machine tool incorporating two angular axes as an inverted SCARA arm and a vertical, linear Z-axis, is described. A build surface on which a 3D object may be additively built is rotated around a lambda axis and also revolved around a theta axis. Embodiments are described that: (i) are free of belts, pulleys, cables and other soft drive mechanisms; (ii) place all three axis motors below a base plate; (iii) direct drive the build surface from shafts of a lambda and theta motor; (iv) are free of a rectangular box frame; (v) use angle sensors mounted directly on motor drive shafts; (vi) measure and compensate for build surface skew; (vii) incorporate a single element for both Z-axis support and a bearing surface. Both device and method embodiments are claimed.

Abstract: A method of creating a chording keyboard mapping table is described. An exercise is created that is performed by users of a keyboard for which a mapping table is desired. The psychomotor performance of the users' transitions between chords is recorded—as distinct from performance relating to chords. A first trial keyboard mapping table (from chords to symbols) is created, and the effectiveness of that table is measured by applying it to a text corpus and measuring the total psychomotor cost to enter that corpus with that table. The table is then permuted, and the cost recomputed. Trial tables are repeatedly permuted, with one or more preferred tables being used as the basis for the next iteration of permutations. This continues until a terminating event, such as minimal improvement, is reached. Variations as embodiments are described. Software to implement the method is claimed.

Abstract: A machine tool incorporating two angular axes as an inverted SCARA arm and a vertical, linear Z-axis, is described. A build surface on which a 3D object may be additively built is rotated around a lambda axis and also revolved around a theta axis. Embodiments are described that: (i) are free of belts, pulleys, cables and other soft drive mechanisms; (ii) place all three axis motors below a base plate; (iii) direct drive the build surface from shafts of a lambda and theta motor; (iv) are free of a rectangular box frame; (v) use angle sensors mounted directly on motor drive shafts; (vi) measure and compensate for build surface skew; (vii) incorporate a single element for both Z-axis support and a bearing surface. Both device and method embodiments are claimed.

Abstract: A method of generating symbols from a chording keyboard is described. A unique feature of this method is accepting a sequence of chords from the keyboard without either an intervening chord or a requirement that all keys be released between chords. Another unique feature is that the chord map is independent of chords before or after a particular chord, for a particular symbol. That is, a user need only memorize one chord for each symbol, and then may transition directly from exactly that chord to any other chord. There are no special transition requirements. The number of keys on a keyboard for this method may be 4 to 10, inclusive. Such a keyboard may be operated with one hand. Specific attributes of embodiments or chord tables are described.

Abstract: A 3D printer incorporating two angular axes as an inverted SCARA arm and a vertical, linear Z-axis, is described. A platter on which a 3D object is built is rotated around lambda axis and revolved around a lambda axis. Embodiments are described that: (i) are free of belts, pulleys, cables and other soft drive mechanisms; (ii) are free of any lead-screw compensating devices; (iii) are free of rectangular box frame; (iv) translate X-Y-Z voxel coordinates into an angular coordinate system, optionally in real-time; (v) optimize non-sinusoidal drive waveforms for stepping motors; (vi) deal with special cases at or near the lambda axis; (vii) measure and compensate for non-orthogonal platter skew. Both device and method embodiments are claimed.

Abstract: A method of creating a chording keyboard mapping table is described. An exercise is created that is performed by users of a keyboard for which a mapping table is desired. The psychomotor performance of the users' transitions between chords is recorded—as distinct from performance relating to chords. A first trial keyboard mapping table (from chords to symbols) is created, and the effectiveness of that table is measured by applying it to a text corpus and measuring the total psychomotor cost to enter that corpus with that table. The table is then permuted, and the cost recomputed. Trial tables are repeatedly permuted, with one or more preferred tables being used as the basis for the next iteration of permutations. This continues until a terminating event, such as minimal improvement, is reached. Variations as embodiments are described. Software to implement the method is claimed.

Abstract: A method of generating symbols from a chording keyboard is described. A unique feature of this method is accepting a sequence of chords from the keyboard without either an intervening chord or a requirement that all keys be released between chords. Another unique feature is that the chord map is independent of chords before or after a particular chord, for a particular symbol. That is, a user need only memorize one chord for each symbol, and then may transition directly from exactly that chord to any other chord. There are no special transition requirements. The number of keys on a keyboard for this method may be 4 to 10, inclusive. Such a keyboard may be operated with one hand. Specific attributes of embodiments or chord tables are described.