A method for entry and recognition of elements from a set of symbols, involving a template of line segments displayed on an electronic writing surface. A stylus is applied to the electronic writing surface so as to trace a desired symbol. A computing arrangement is used to "snap" the strokes made by the stylus onto the corresponding template line segments. Upon completion of a symbol, a code is made to represent the line segments and this code is used to reference entries in a data structure to identify the appropriate corresponding computer code. If there is no match, the code for the line segments and a corresponding set of computer codes can be added to the table. This method takes advantage of natural handwriting skills and can be used for a variety of symbol sets.

Recording apparatus is disclosed adapted for connection to a telephone network and to receive voice signals therefrom characterized by an encoder for converting voice signals received from the telephone network into an optically readable image using a predefined code and a printer for printing the optically readable image. Also provided is playback apparatus comprising an optical scanner for producing a digital representation of a document on which is printed an optically readable image, a decoder for converting the optically readable image into audio signals using a predefined code and a transducer for producing a sound corresponding to the audio signals. The recording apparatus and the playback apparatus can be integrated into a single apparatus. In a preferred form of the invention, a device is provided which is adapted for connection to a conventional fax machine to form such recording or playback apparatus in conjunction therewith.

A machine-readable matrix-type code has either repeated or non-repeated dot patterns in one direction representing digital characters which are read by a sensor moved in a direction which is generally normal to the patterns. The patterns of the code may be formed in a manner wherein the sensor views a portion of repeated patterns, or the code may be of lesser magnitude wherein the entire non-repeated pattern area is covered by the field of view of the sensor.

A semiconductor wafer (50) is inscribed by a laser scribe system with a numeric wafer identifying number in binary dot-array encoded form to facilitate machine readability. A matrix (20) of predetermined dot locations on the wafer defines a series of parallel columns (e.g. 28) of dot locations, each column corresponding to a respective digit of the ID number. In each column, a number of dots equal to the numeric value of the corresponding digit plus one (N+1) is marked in a contiguous series starting from a baseline row (27,39) of the matrix. A pair of dot arrays (20,30) thus formed are aligned for convenient validity checking. The wafer area required for a dot-array encoded ID number is less than the area required to write a single digit of the ID number in alphanumeric form (14).

A coded label comprising a code pattern in which first and second segments respectively being substantially square and having reflection factors different from each other are arranged in at least four rows and two columns, and in which at least two of either of the first and second segments are arranged in each column and at least one is arranged in each of the uppermost and lowermost rows.