Abstract: A horizontal display positioning circuit for a CRT-type display device includes a microcomputer, a horizontal deflection circuit, and a horizontal positioning control circuit configured between the microcomputer and the horizontal deflection circuit, for outputting a horizontal sync signal having a predetermined duty width. The microcomputer, which receives synchronizing signals from a host computer and discriminates a video mode according to the received synchronizing signals, outputs a horizontal sync signal having a given polarity. The horizontal deflection circuit includes a horizontal oscillating circuit which generates a horizontal deflection signal, a horizontal drive circuit which performs waveform correction of the generated horizontal deflection signal and drives an output transistor, and a horizontal output circuit which includes the output transistor and produces a sawtooth current through a deflection coil based on the operation of the output transistor.