Genlock circuit plan / schematics urgently needed

[Bildheinze]

Hy!
Does anyone know know where i can find a circuit plan for an amiga genlock?

it doesn't matter which one any plan would help,it's just to understand the principles of how the amiga video signal and composite will get together,

a plan for a electronic design sirius genlock would be perfekt,but really anything would help..

thanks a lot,

Heinzer

[Zac67]

Got no schematics, but maybe this also helps:

Essentially you activate _XLCKEN and feed the external sync (extracted from composite) into _XCLK - this synchronizes the Amiga's output to your external source. Adding a PLL will make your Amiga survive a dis/reconnect of the external sync source (it won't break but it'll crash otherwise).

Then you use the _PIXELSW signal to switch between the external composite and the Amiga's (depending on the model you may have to generate that first). _PIXELSW is active when the background palette color 0 is output.

Alternatively you can use any color code from RGBI and/or analogue comparators to generate color keying, depending on what you're after.

I don't know if a 4066 bilateral switch is fast enough for video applications, but you need something like that with a switching rate of ~15 MHz.

[a4k-oerx]

Here is a website which has a self-made Genlock, but unfortunately the pictures and PDFs with schematics are not online, maybe you can ask the website owner for them...

http://www.savel.org/hardware.html
http://www.savel.org/old/amiga/genlock.html

Here is another website which has Service manual Genlock, released June 1987, part number 314983-01, includes the full schematics, theory of operation, troubleshooting guide and parts list for the Amiga Genlock. Used. for 10€, maybe it helps.

http://www.amiga-stuff.com/forsale.html

[Bildheinze]

Thanks for the links!

What i'm doing is building a genlock which reacts to audio.
see in my pictures.

while building it i found out it can do some nice effects....now i was wondering if i can connect another video source into the input where normally the amiga signal goes in..(using the genlock as a 2 channel video mixer)...i connected  a composite through an rgb splitter to the port where the amiga signals go in...seems to work..colours are good but its out of sync...so need to do some research on where hsync and vsync gets generated and so on.....will check out the links..thanks..later

[Zac67]

Sure you could also feed in a 3rd signal - but as you've noticed it'll need to be synchronized to the rest...

If the source can't be synchronized by itself you'll have to get an external frame synchronizer.