ATV PIC INTERLACED 625 SYNC GENERATOR
Sometimes an ATV guy needs to generate interlaced syncs for other equipment to lock onto such things like sync separators or ident in picture generators or in my case the Teletext Generator.... This saved me connecting up another video source that may or may not have been accurate....
Life is much easier now than when I first started up you had a series of Valve Dividers that drifted a little and had about 20 valves in it ECC81 I think... You had to wait half an hour for things to WARM up the shack..... The good old days.... then a transistor model came along.... now its two chips... and no gravy.
Well by now you should know I like PIC's so into service goes the PIC16F84/PIC16C84 this was clock driven from an EX03 selectable XTAL....The EX03 was set to give 8MHz output..... There is a DIP SWITCH fed into the PIC as an option just in case you want to add other software.... All the timings are very simple and are NOT due to interrupts but mainly timed call instructions.... The actual PIC rums at (2MIPS) 2 million machine instructions per second so reasonable delays can be selected..... In addition you could make a Grey Scale if you output the numbers shown in the table instead of the call black_line ..... fixed delays of 2 to 10u/S are produced and every 0.5u/S anything less than this is done with NOP instructions..... Very Simple you just need a few resistors and a transistor...... I have enclosed the basic software and a circuit......... G3RFL