Abstract: The invention concerns a stylus for use with a digitizing tablet. The stylus stores information which identifies characteristics of a user's handwriting. These characteristics are transmitted to a computer when the user interfaces with the computer, and are used by the computer to recognize the user's handwriting.

Abstract: The invention relates to the transmission of telemetry data from a stylus to a host computer via a serial, asynchronous data channel. The telemetry data is encoded into code-words using a specially selected error detecting or error correcting code, the code-words are transmitted from the stylus in a continuous, homogeneous data stream without the use of framing delimiters between adjacent code-words, and the code-words are then received by the host computer which separates the code-words according to the unique characteristics of the selected code. The code may be chosen based on both the error detection/correction requirements of the system and the probability that the code will create invalid intermediate code matches between consecutive back-to-back code-words. In one embodiment, the invention provides a synchronization scheme which greatly reduces the probability that invalid intermediate code matches will be recognized in the host computer as validly transmitted code-words.

Abstract: The invention concerns a stylus for use with a digitizing tablet. The stylus stores information which identifies characteristics of a user's handwriting. These characteristics are transmitted to a computer when the user interfaces with the computer, and are used by the computer to recognize the user's handwriting.

Abstract: The invention concerns a stylus for use with a digitizing tablet. The stylus stores information which identifies characteristics of a user's handwriting. These characteristics are transmitted to a computer when the user interfaces with the computer, and are used by the computer to recognize the user's handwriting.

Abstract: The invention concerns a stylus for use with a digitizing tablet, such as that associated with the display of a portable computer. The stylus contains memory which stores data such as operating state (i.e., states of user-controlled buttons, state of charge of battery), a stylus identification code, and fault codes, which indicate error conditions which arise. The invention transmits the contents of memory, by a serial bit stream, to the computer.

Abstract: The invention concerns storage of correction tables for digitizing tablets. A digitizing tablet produces data indicative of position of a stylus. The data does not, in general, exactly indicate the position; errors exist. For example, a tablet may produce a data pair indicating a Cartesian position of (5.0, 6.0) when the position is actually (4.9, 6.1). Correction tables are used to correct the errors. These tables may be viewed as containing correct data for each possible pair of data produced by the tablet. Thus, in this example, a user would (a) receive (5.0, 6.0) from the tablet, (b) look up this data in the table, and (c) find that the actual position which corresponds to this data is (4.9, 6.1). The invention concerns compression of such tables, to reduce storage space.

Abstract: An integrated circuit driver for high and low lines in a bus. The driver comprises first and second current sources connected to high and low voltage sources, respectively, and first and second transistor circuits for blocking voltage spikes higher or lower than the voltages provided by the high and low voltage sources. The first current source and the first transistor circuit are series connected between the high voltage supply and the high line, and the second current source and the second transistor circuit are series connected between the low voltage source and the low line.