title: A versatile programmable pattern generator.
abstract: A versatile visual pattern generator is described that can be programmed by a microcomputer and is developed as a part of a portable visual evoked potential analysis system. The hardware is contained on one printed circuit board (3" X 10", 7.5 X 25.5 cm) residing in an interface connector of a microcomputer (Apple II). The generator produces signals for commercial 50 Hz video monitors; a calibration procedure based on a photocell measurement corrects for the non-linear voltage intensity characteristic of the phosphor of the video monitor.
mesh_terms: D003196:Computer Graphics; D003201:Computers; D004594:Electrophysiology / Q000295:instrumentation*; D005074:Evoked Potentials, Visual; D008838:Microcomputers; D010364:Pattern Recognition, Visual