VDM-1

The Processor Technology VDM-1, for Video Display Module, was the first video card for S-100 bus computers.^[1] It was created in 1975 and allows an S-100 machine to produce its own display. When paired with a keyboard and Processor Technology's 3P+S card, it eliminates the need for a separate video terminal. Using a 7 x 9 dot matrix and ASCII characters, it produces a 64-column by 16-row text display.

The VDM-1 is a complex card and was soon replaced by an increasing number of similar products from other companies. An early competitor was the Solid State Music VB-1,^[2] which offers an identical display from a much simpler card. Later cards using LSI chips have enough room to include the keyboard controller as well.