Thanks for the explanation! The ZX81 display is broadly similar yes.
So just to clarify are your lines still the standard PAL timing (about 64 microseconds)? Also I never would have thought of using a PIC serial port that way. What speed is it running at?
I enjoy PICs for much the same reason as I think you do, it's nice to be close to the metal, counting instruction cycles and the like, and thinking up new "twists" on the hardware.
Also, I love those little CRTs from Brazil
