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Ami_GFX · 25 September 2011, 02:32

The sync strainer is is a dongle that attaches to the Amiga RGB port and is intended to be used with the Video Toaster. When the Toaster is started, the Amiga goes into genlock mode and the Horizontal and Vertical sync signals are set to 7.8khz and only composite sync is outputed from the RGB port. The 1080 monitors have a composite sync input and function with the Toaster but most other monitors, even old 15khz CGA ones don't, and the Sync Strainer separates the 15khz horizontal and vertical sync signals from the composite sync and outputs them.

In genlock mode, the Amiga can be synced to an external video source and Amiga graphics can be overlayed onto incoming video. The Video Toaster is the the best genlock device ever made for the amiga but even a Commodore 2300 will do the basic genlock functions. This limits the Amiga video to frequencies that are compatible with NTSC or PAL video signals. The basic 15khz Amiga modes work but no DBLNTSC or DBLPAL and some 15khz display modes work better with a genlock than others.

I've changed the sync input on the Flicker Magic from the horizontal and vertical signals on the Alice chip to the output of the sync strainer though a 15 pin VGA input port I added to the Flicker Magics bracket.

At this point, my next step is to dig out my oscilliscope and take a look at the sync signals to see what the differences are. The distorted video is very stable which is a good sign and indicates a timing issue with the horizontal sync signal and the rest of the video signal.

25 September 2011, 02:32	#6
Ami_GFX Registered User Join Date: Sep 2011 Location: USA North America Posts: 211	The sync strainer is is a dongle that attaches to the Amiga RGB port and is intended to be used with the Video Toaster. When the Toaster is started, the Amiga goes into genlock mode and the Horizontal and Vertical sync signals are set to 7.8khz and only composite sync is outputed from the RGB port. The 1080 monitors have a composite sync input and function with the Toaster but most other monitors, even old 15khz CGA ones don't, and the Sync Strainer separates the 15khz horizontal and vertical sync signals from the composite sync and outputs them. In genlock mode, the Amiga can be synced to an external video source and Amiga graphics can be overlayed onto incoming video. The Video Toaster is the the best genlock device ever made for the amiga but even a Commodore 2300 will do the basic genlock functions. This limits the Amiga video to frequencies that are compatible with NTSC or PAL video signals. The basic 15khz Amiga modes work but no DBLNTSC or DBLPAL and some 15khz display modes work better with a genlock than others. I've changed the sync input on the Flicker Magic from the horizontal and vertical signals on the Alice chip to the output of the sync strainer though a 15 pin VGA input port I added to the Flicker Magics bracket. At this point, my next step is to dig out my oscilliscope and take a look at the sync signals to see what the differences are. The distorted video is very stable which is a good sign and indicates a timing issue with the horizontal sync signal and the rest of the video signal.