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Build your own switchbox.

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Lac

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Just wondered if I'm able to build a switchbox myself with only a pair of switches, or does it include more advanced electronics like microcontrollers? You know the boxes used to share one monitor between two computers.

Cheers!
Lac.
 
using 1 screen on 2 (or more) computers is easely done with a busswitch (i've made several such boxes in the past)...

I've copied the idea from one of those old Voodoo 3DFX cards. They used a QS3384 10 channel switch...
https://www.idt.com/docs/QS3384_DS_27540.pdf

As there are only 5 wires in a VGA signal that carry the actual video (R-G-B - HSYNC - VSYNC) you can use both pairs of 5 switches to switch trough 1 computer each (and be sure never to switch both paires at once)...

VGA pinout:
**broken link removed**

DDC DATA and DDC clock are not needed for the actual video, they are the signals that makes it possible for a computer to recognize the monitor (and only allow the supported refresh rates). If you want these to be used to you can also switch them, as they are just 5V digital you can fo this with a simple transistor.
The only problem for recognition is that windows only communicates with the monitor once, at startup, so for the monitor to be recognized it should be connected to the computer while windows starts.

The actual video however, can be switched at any moment, using the busswitch.

You could also use a mechanical switch, but VGA signals are very small signals, as the contacts get dirty video quality will decrease, so an electronic solution is better.
 
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