|Could anyone provide any information as to how to add text to a NTSC video
|signal?  The only solutions I have been able to find only work with component
|signals.  A PIC solution would be nice (16C74 preferably).

Adding text to an NTSC display will require doing three things:

[1] Detection of the incoming sync signal
[2] Setting the DC offset of the incoming signal as appropriate
[3] Switching between the incoming signal and your own.

Although it's certainly possible to use discrete components to do
the above functions, it may be easier to use a chip designed for
on-screen display purposes.  I think other people here have written
of such devices.