[Coco] PICs and S-Video

John Kowalski sock at axess.com
Wed Feb 22 16:02:22 EST 2006

At 09:37 PM 21/02/2006 -0600, Chris Hawks wrote:
>    I'm working on delaying it (by almost a whole line), but, the TTL is
>getting pretty complicated. It was suggested that I use a small PIC, but,
>I've never used them before and don't have a programmer. Seems pretty
>brain-dead. One input, one output and a comaparator/analog input. Take an
>interupt on HSYNC, start a countdown timer (value based on the pot
>connected to the comparator/analog input), take an interrupt on time-out
>and output the HSYNC pulse then. 
>Suggestions, input, offers to help???

Maybe I'm overlooking something, but it seems that maybe an ordinary 556
(dual timer) chip could do the trick.  It wouldn't delay the HSYNC per-se,
but I figure it could be used to generate a new HSYNC signal using the
original HSYNC for reference.

Possibly something along the lines of:
-Timer 1 being set to the delay between the original HSYNC and the new HSYNC.
-Timer 2 being set to the pulse width of the new HSYNC.
-The original HSYNC would trigger timer 1 and reset timer 2.
-The output of timer 1 would be your new HSYNC and also trigger timer 2.
-The output of timer 2 would reset timer 1.

                                         John Kowalski (Sock Master)

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