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Two computers, one monitor, zero fiddling (2025)

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Re: Two computers, one monitor, zero fiddling (2025)

#51

Post by iaresee »

amiga386 wrote: post #47

With Windows and AutoHotkey and https://www.nirsoft.net/utils/control_my_monitor.html You can add this .ahk script to run at startup: ^F4:: Run C:\Users\YourNameHere\Documents\AutoHotkey\ControlMyMonitor /SwitchValue Primary 60 17 3 Return Where the file path is where you've put ControlMyMonitor.exe, "Primary" means the main Windows display, the "60" means input select, and the "17" and "3" are the values you observe…

Oh nice! I've been doing this on the Mac side with BetterDisplay, but on the Windows side I couldn't find an equivalent and have had the awful Dell software installed to do it there. This'll let me dump the Dell software! Thanks!

Re: Two computers, one monitor, zero fiddling (2025)

#52

Post by ndr42 »

pavel_lishin wrote: post #40
spacedoutman wrote: post #26

Personally i prefer two computers, two monitors, one mouse/keyboard. Deskhop has been a lifesaver https://github.com/hrvach/deskhop

For macs, if you're signed into the same Apple account on both, you can "share" the same keyboard and mouse across them. It does tend to be finicky - sometimes it just refuses to connect, and won't tell me why, and sometimes it'll forget the arrangement. And it requires you to be signed into one account on two machines, which some people may not want to do on corporate laptops.

Yes and then sometimes your mouse is gone (just to be found on some iPad display) :-/

Re: Two computers, one monitor, zero fiddling (2025)

#53

Post by EvanAnderson »

topspin wrote: post #48
Vvector wrote: post #5

Earlier quoted context omitted.

He bought a $900 monitor that has a KVM built in

~$900, and it takes ~3 seconds to switch... I'll pursue this when "they" decide to get real and make this not suck. Until then, I have sufficient alternatives. I appreciate the writeup. It convinces me that integrated KVM stuff ~~ except for fewer wires ~~ isn't much better than the mess that's prevailed for years now, and I'm not missing much.

The ~3 second switch would definitely derail me.

Why does video input source switching suck so much?

Back in the old analog CRT days I could forgive the switching latency. With today's all-digital signal paths I feel like video input switching should be pretty close to instant.

Is the technology in a broadcast switcher really so exotic and expensive?

Re: Two computers, one monitor, zero fiddling (2025)

#55

Post by jmuguy »

Its amazing to me how annoying these problems can be and there's no real one size fits all solution. I have a desktop PC and macbook, and two monitors. I use a KVM and also switch inputs on the monitors themselves.

I tried very unsuccessfully to do something with DDC/CI when the KVM would switch between systems. The idea being when the OS detect the presence of the keyboard/mouse because the KVM had switched to them they'd send a change source command but DDC/CI is such a disaster in terms of support.

We need someone like Framework to make a "monitor for hackers" that actually has robust, well documented, DDC/CI support and I'd be all over it.

Re: Two computers, one monitor, zero fiddling (2025)

#56

Post by heatmiser »

I solved the multi-computer-to-multi-monitor problem with a Level1Techs KVM[1]. The price (~$500 for the variant I purchased) initially gave me pause, but the longer I've had it, the happier I am with my decision.

It handles all the switching at the hardware level and thus has no perceptible lag for video or anything else. I'm able to connect a single set of peripherals, in my case, two monitors, a keyboard, a trackball, and a USB audio interface, to both my Linux desktop and a CalDigit Thunderbolt dock connected to my laptop. The L1T KVM has hotkeys[2] that let me switch between systems, with only a 1–2 second delay.

The benefit, for me, of this extra box now mounted under my desk is that when I upgrade my monitor, I only care about how good a display it is, not whether there's some perfect confluence of KVM, refresh rate, aspect ratio, display technology, etc. I find the monitor I want and let a separate IO routing layer.

--

[1]: https://www.store.level1techs.com/products/p/14-kvm-switch-d...

[2]: https://forum.level1techs.com/t/official-l1techs-kvm-faq-ult...

Re: Two computers, one monitor, zero fiddling (2025)

#57

Post by elric »

IshKebab wrote: post #22

You can do this with even less fiddling just by getting a KVM that supports video. There are reasonably priced ones that can even do 4K 60Hz. This also means you don't have to deal with monitors that don't implement input switching via DDC/CI (thanks LG).

Last time I looked (which was some years ago), I couldn't find any that support display over Thunderbolt without resorting to DisplayLink.

Re: Two computers, one monitor, zero fiddling (2025)

#58

Post by swiftcoder »

bartvk wrote: post #24
swiftcoder wrote: post #11

Earlier quoted context omitted.

Any somewhat-modern monitor with multiple outputs should be able to do this. DDC support has been around for a while

Yeah but this monitor also switches its internal USB hub to USB-C. Is that really standard behavior?

For monitors with DisplayPort over USB-C, yes. The most common machine on the other end of that cable tends to be a MacBook, and nobody wants to run 2x usb-c cables from their MacBook to their monitor.

Re: Two computers, one monitor, zero fiddling (2025)

#59

Post by topspin »

EvanAnderson wrote: post #53
topspin wrote: post #48

Earlier quoted context omitted.

~$900, and it takes ~3 seconds to switch... I'll pursue this when "they" decide to get real and make this not suck. Until then, I have sufficient alternatives. I appreciate the writeup. It convinces me that integrated KVM stuff ~~ except for fewer wires ~~ isn't much better than the mess that's prevailed for years now, and I'm not missing much.

The ~3 second switch would definitely derail me. Why does video input source switching suck so much? Back in the old analog CRT days I could forgive the switching latency. With today's all-digital signal paths I feel like video input switching should be pretty close to instant. Is the technology in a broadcast switcher really so exotic and expensive?

> Is the technology in a broadcast switcher really so exotic and expensive?

No. My characterization of the problem was precision flippancy; the demand for this is niche enough that optimizing for it is a low priority, so "they" simply don't. That failure is stack-wide; the specifications around display negotiation would need extension to manage the additional state necessary for the "agile" KVM use case, and then the hardware+firmware would need to exist and become cheap, somehow despite Imaginary Property laws, so that one could hope to find it in real products.

There is regulatory friction here as well: it would complicate power management. Not infeasibly so, but enough that unless a need appears of such import that it motivates people to dare to disturb that writhing ball of copulating tapeworms, it simply won't happen.

So don't hold your breath. Unless you're relatively young, you won't live to see it. More likely, some other paradigm will obviate the problem first.

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