I soldered up a 4x4 matrix keyboard together with the PIC16F1705 and two resistors for mixing the monochrome video and the syncs.

Then spending 4-5 hours coding up the basic code for outputting stable syncs and a bitbanged video with the pixels coming from RAM (not hardcoded) I was amazed that my TV actually showed a fairly stable image on the first try.

I must admit that I used the simulator in MPLAB X to check the timings - but still... First try!

This is how the 64x32 pixels with a 0x55/0xAA grid looks like.

There seems to be some sync issue in the last row....