Abstract: Apparatus for digitally recording and analyzing electrocardial and other bioelectric signals, includes a port for connecting an external measuring device; first and second differential input channels for receiving a data signal from the measuring device and for amplifying and filtering the data signal; a compression circuit for compressing the data signal from the input channels so that the compressed data signal includes only changes in amplitudes at particular points, along with a measure of elapsed time since a previous change in amplitude at the particular points, thereby omitting redundant points of the data signal; a random access memory for storing the compressed data signal; a microprocessor for controlling the storage of the compressed data signal in the memory; a power management circuit for turning power to the apparatus ON and OFF at predetermined intervals; and a position switch for indicating the position of a person wearing the apparatus relative to a vertical position.