Compaq QVision Graphics System Installation Manual page 21

QVision Operations and Installation Guide
Sync Signal Definition: Horizontal and vertical synchronization signals
conform to the RS-343-A voltage level standards and use the normal
horizontal input.
Separate TTL Syncs, Separate
Videos
This scheme uses all 5 of the BNC connectors.
Video Input Characteristic: Typical input impedance of the videoamps is
75 ohm.
Video Sync Definition: The three video inputs consist of red, green, and
blue signals, each with its associated return, driven into a terminated line.
The video signals are analog levels, where 0 volts corresponds to black,
and 700 millivolts is the maximum signal amplitude.
Sync Signal Definition: This scheme utilizes separate horizontal and
vertical synchronization signals which are generated by a TM or TTL
equivalent source.
Input Voltage Levels: All signal levels between 0 and 0.8 are defined as
logic 0. All signal levels greater than 2.0 are defined as logic 1.
Sync Polarities: Both horizontal and vertical sync signals are defined as
negative true.
A-3