On Fri, 05 Sep 2014 09:31:13 -0700, KenO wrote:
My reason for asking this question was told "C-Series ex-link is on
TTL-Level (0V to +5V) while your PC operates at RS232-Level (-12V to
+12V) so your cable has to have at least some kind of Voltage-level
shifter."

Not all sub-D connectors are created serial ports ;-)

The VGA connector on a PC is a female 15-pin sub-D carrying TTL levels.

If your PC has a 9-pin male sub-D, that would most likely be a COM port
carrying RS232-level signals. Sending video over this port is a no-no.

Cheers!