Vertical Sync problem

 

I have used an old (1980’s) computer to generate titles for video recorded on to my VCR. This works fine, however I have tried to connect this antique computer to a DVD recorder and the computer-generated picture slowly rolls upwards.

 

I believe that this is a “negative” (vertical) sync problem, and an additional circuit is required to correct this rolling picture.

 

Does anyone know where I can obtain, (in order of preference):-

 

1. a ready-built adapter to cure this vertical sync problem.

2. a kit of parts to home build an adapter.

3. a diagram of how to build such a device.

 

Please post links to any site which you think may help me cure my rolling picture problem.

How are you trying to connect the DVD recorder?

How are you trying to connect the DVD recorder?

 

Connecting the "composite PAL" signal from the computer to the "video input" of the DVD recorder.

As I said this works fine with the VCR, but the vertical syncronisation of the DVD is different,

I believe some sort of inverter circuit is required to change the direction of the vert sync pulse.

 

(Incidentally a "vertical sync" output connection is available at the computer).