This remarkable raster-scanned CRT was designed by Conrad Odenthal and featured a small spot size that was constant over the entire screen using dynamic focus and dynamic astigmatism to produce a 2048 x 1536 pixel display. Additionally, the grid capacitance was unusually low to enable high speed Z-axis switching of the 3.1 megapixels at a 60 Hz refresh rate. The low capacitance in combination with a Tektronix-designed Gallium Arsenide IC amplifier, resulted in GMA 201, 202, and 251 monitors' Z-axis bandwidth exceeding 200 MHz.

This paper by Conrad from the SID 1984 Digest describes the CRT design. Click on the image to view the PDF. The paper is courtesy of the Society for Information Display. © Society for Information Display.


Used in the GMA 201, 202, and 251 monitors, this CRT provided performance "beyond the state-of-the-art". Typical applications for the GMA 201 and 202 included Digital Radiography (X-rays and Mammograms), and gray-scale imaging. The GMA 251 included a 2048 x 2048 x 8 bit frame buffer to store and view images used in Picture Archiving, Reconnaissance, and Computer-aided Publishing.

This GMA-251 brochure describes the features of the display monitor. Click on the image to view the PDF.