I use a Belkin F1DS104PY, 4 port PS/2 and VGA switch. No power adapter required. Works great although sometimes the mouse takes a few seconds to connect fully when switching.

I second Belkin. No matter your requirements they always have something that will suit. Ive used their desktop units as well as 4, 8 and 16 port rackmount parts. Pretty solid throughout.

I had 4 port belkin. It was nice but the cables were expensive and bulky and if I was only using one computer, every time I powered it down, the switch would reset to port 1. When you have 5 cables coming off the box, it takes up some space.

I last year I replaced it with an HP 2x16 kvm switch on the cheap that uses cat5 with interface modules. It works with a usb keyboard and mouse and takes a standard power. It connects to computers with VGA/ps2 modules that are cheap or VGA /USB modules that are expensive. It was cheaper to just buy a ps2 pcie card thN buy the usb module. The switch has an OSD that lets you name the computers, which is great when you got a bunch of computers to flip through but is less than ideal if you want to do something immersive.

Neither switch did audio.

I'm using an IBM Netbay LCM. Honestly, it's the final kvm I'll ever need 😁

It'll hold up to 255 devices and connects dongles with standard cat5 networking cables.
The only disadvantage is, I've only got 7 dongles and it's hard to find more 😀

Hehe, that applies to a lot of the more custom hardware: only as useful as the cables you can find.

What is best depends on your systems. I've been flipping between PS/2+VGA and DIN+serial+VGA a couple of times. I currently have an 8-port Aten CS-88A with 2x PS/2+VGA for my retro rigs. It works fine, but means I need serial -> PS/2 adapters on the older systems. I also have a Startech SV421+ with PS/2, VGA, serial and DIN, but only 4 ports. It's amazing and I'd use it exclusively if I could find an 8-port version.

Thank you very much everyone for the recommendations, I'll see what I can buy in my country.

And I'm looking for one with DVI and PS/2 to the computers. 4 ports preferred.

I use one of these https://www.newegg.com/planet-kvm-400-d-sub/p … 82E16817187003R for my WinXP and Win98 machines, works like a charm, even without an additional power supply!

I had an 8 port Compaq rackmount KVM. although these cheap 4 port ones were actually better as the Compaq wouldn't work with my S3 Virge. They sell under all different brands in black or silver. Even period correct as got the first one in early 2000's and last one about 3 years ago.
https://business.currys.co.uk/catalogue/compu … -ports/P187740P

I've used rackmount Aten KVM's and liked the build quality but were used for servers not gaming.
Also used Belkin but again just for business use.

I'm still using VGA so can't recommend anything in DVI. For the few PC's that are using DVI I just run the cable direct to the screen as you only need the keyboard hooked up to the KVM for it to be recognised.