[comp.graphics] RGB to NTSC encoder - the Motorola MC1377 chip

brian@ucsd.EDU (Brian Kantor) (07/20/88)

We have several Sun workstations here equipped with the old Sun-1 colour
display board that seems to generate RGBS at North American (RS170A) scan 
rates.

I'm contemplating building a simple RGB to NTSC encoder so that images
can be videotaped, and I've found what seems to be the perfect chip for
doing so: the Motorola MC1377.  It is designed specifically for this
purpose and needs a minimum of external components.  It costs the
distributor about $2 and so the small-quantity price to us is under $5.
Apparently all you need to add is a 3.579545 MHz crystal, a small tuned
transformer, a delay line, and various support glue to make it work.
There's even a simpler version of the circuit that doesn't need the
transformer and delay line (with a lower-quality output signal, of
course!)

Has anyone played with this chip?  I've got a couple on order, and I'd
appreciate any advice on things you've found out whilst playing with
this particular chip.

(I know there will other problems to solve, such as bandwidth-limiting
the signals INTO the chip.  I've built lots of little filters and delay
equalizers and widgets like that before, so that's not a problem.)

	Brian Kantor	UCSD Computer Graphics Lab
			brian@ucsd.edu