Vertical Sync problem

[Igor Suman]

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.

[Klaynos]

How are you trying to connect the DVD recorder?

[Igor Suman]

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).