VGA splitter - cropper

[GreekPIC]

I want to cut four parts of a VGA output and direct them to 4 outputs. That's what I was thinking of doing:

Use a PIC to monitor the V-sync and H-sync lines and control transistors connected to the RGB signal.

When the PIC detects a H-sync pulse it will wait for a set time (in order to create an offset from the left of the screen), then send the H-sync pulse to the first output, then activate the transistors connected to that output.

Let the line scan, deactivate the transistors, wait for the offset and repeat for output 2. The same would happen with the V-sync.

Do you think it would work this way?

View attachment 36643

 

[GreekPIC]

Oops! Forgot the other pic...

View attachment 36644

 

[GreekPIC]

Anybody??

 

[audioguru2]

Hi Greek,
Your idea will result in the left part of the picture missing and replaced by black. You need to delay the video by digitising it, storing it in RAM and play it back as VGA after your offset time has past.

 

[GreekPIC]

What I want Is the left part of the original picture to be missing!

But if I send a H-sync to the first output wouldn't it start displaying what's there (having skipped the left part) right away? Why would it display black?

Thanks,

Nikolas

 

[audioguru2]

Hi Nikolas,
Sorry, I thought you wanted to make an offset.
Sure, send a H-sync pulse to an output monitor then send it the video, and block the original sync and the parts you don't want to be seen on it.
Its picture will be small, the same percentage of the total screen as the original. What are you going to show on the remainder of the screen?

 

[GreekPIC]

I made a litle graphic of what I want to do. To have the video card working at a high resolution and display four parts of the image on four small monitors at lower resolutions. E.g 1600x1200 ->4x 640x480 (with offsets) or 1280x960 ->4x 640x480 (no offsets, the image divided equaly to four parts).

 

[audioguru2]

Hi Nikolas,
I should work fine when you send a small high resolution image with the sync you created, to each other monitor that have their resolution reduced to make the picture fill their screen.