With no CRT monitor connected to a pc the Hsync and Vsync pins will stay at
5V. Power down , connect monitor , power up both and Hsync and Vsync drop to TTL logic High but what is also required to make the pc send out sync pulses to the monitor ? Do the DDC lines do more than identify the monitor type ? ie if that data is absent will the pc not respond at all.- posted
18 years ago