What is happening with my computer?

[MrScout800]

Hello, I recently acquired a disk drive for my computer and connected it to the computer I have, it seems to be doing something but I am not sure what. Something is clearly wrong, I’ll try to send a short video of what it’s displaying on the screen. Anybody know why it’s doing this? There’s an input and output coaxial on the back of each machine. The screen gives me a very similar result when I bridge its coaxial I/Os together with a coaxial cable but now it’s doing it through the disk drive machine when I switch it on? Is this a sign of life or a sign that something is fatally wrong with the machine and I need to find the issue?
Thank you.

 

[MrScout800]

Here’s a close up of the screen with the brightness and contrast changed