The MSK 621(B) is a very high frequency video amplifier system capable of driving displays with resolutions up to 1664 x 1200. Brightness is controlled with a gated differential input black level clamp comparator. There are also DC inputs available for contrast control and drive control. All DC control inputs operate over a 0V to 4V input range and feature high impedance inputs. In addition to all of the features offered in the MSK 620, the MSK 621 contains an emitter follower buffer output stage which allows the device to easily drive video lines at greater current levels. The MSK 621(B) is packaged in a space efficient hermetically sealed 18 pin dip package.