Actually, I'm wrong (as usual). Having just been trying to bash my various scribbled notes together into something for future reference and sorting out the multitude of different sized TCF images that have been through Photoshop on the way to the final ROM image, I realise that my quoted 720 pixel figure for the active line at 625 was part of earlier calculations for a theoretical faster clock speed
The active line pixel count with 625 lines at 12MHz is 625 pixels (square pixels). However, the total count of 768 for the entire line (64uS) is correct. Sorry
Maybe I
will up the clock speed a bit then. Thanks to all for the input.
Parabola