Only pro stuff does a good job switching the VGA signal from my experience. I use an Extron MVX84 VGA matrix for my switching needs (1920 x 1440 and higher resolutions, which it handles perfectly), but only because I paid very little money for one.

That looks like a pretty low-end modern solution, so better KVM switches would probably perform better. I have an Aten CS-88A which is pretty decent at 1024x768@85 - in fact it was still good at 1280x1024@85 on a newer Iiyama 17" that could go up to 1600x1200@75 (which did not look good via the KVM, but that is pushing it for any analog connection). A lot depends on your cables too. Bad or excessively long cables will ruin quality. Your link doesn't mention anything about cables supplied with that 'thing', which doesn't bode well.

As for doing the KVM bit digitally and then converting to VGA - that's possible, but there again, most DVI/HDMI to VGA adapters are modern crap designed for purposes where hi-res image quality wasn't top of everyone's mind.

Tiido wrote on 2025-02-05, 14:21:

Only pro stuff does a good job switching the VGA signal from my experience. I use an Extron MVX84 VGA matrix for my switching needs (1920 x 1440 and higher resolutions, which it handles perfectly), but only because I paid very little money for one.

Yeah, I'm seeing prices of more pro switches, and they are quite steep.

dionb wrote on 2025-02-05, 14:25:

That looks like a pretty low-end modern solution, so better KVM switches would probably perform better. I have an Aten CS-88A which is pretty decent at 1024x768@85 - in fact it was still good at 1280x1024@85 on a newer Iiyama 17" that could go up to 1600x1200@75 (which did not look good via the KVM, but that is pushing it for any analog connection). A lot depends on your cables too. Bad or excessively long cables will ruin quality. Your link doesn't mention anything about cables supplied with that 'thing', which doesn't bode well.

As for doing the KVM bit digitally and then converting to VGA - that's possible, but there again, most DVI/HDMI to VGA adapters are modern crap designed for purposes where hi-res image quality wasn't top of everyone's mind.

Yeah, it didn't came with cables, so I grabbed some off Amazon. The VGA ones were utter crap, with severe ghosting, smearing and a nice vertical line on the image, returned them immediately. Then I also picked up a pricier DVI-A to VGA cable for my XP machine, that only has DVI outputs. There the image was just a tad softer, but still not as crisp as it is on the Me and 2k machine, and not different from the passive adapter I'm alredy using to connect the Syncmaster to that HD4850 (probably I need to find a better adapter, maybe one with a chip that converts signal from DVI-D to VGA). I've ended up returning also the DVI cable and the switch.

I've been looking on the internet for Aten switches, and those larger one are quite pricier, even if they come with all the cables you need. But then I found this smaller one, with pretty great reviews. But it also looks like a generic switch with just he Aten badge on it, different from the pricier ones around. And it only supports two machines when I have three (at the moment)

I'll think about those more expensive Aten switches, especially when those ones have also support for PS/2 connection, meaning I won't also have to switch mouse and keyboard every time I want to use a different PC. Shame I can't find one with both VGA and DVI inputs, since the VGA is mandatory only for the monitor, and not the PCs: all of them have a DVI-I output (unless one of those GPUs fries itself, forcing me to go back to older ones), only one PC has DVI output exclusively. And if I go for the VGA switch, I'll then need something decent to convert that DVI to a VGA. The converter I have now hooked to the 4850 is a passive one, provided with the whole MOBO Combo itself, and it does make the image a tad softer. Not to unacceptable levels, but the softness is evident when I'm used to the crisp image coming out of my other two machines with a direct VGA connection to the monitor.
I wonder if these Aten switches manage to communicate EDID from the monitor back to the PCs...

About the digital solution... If the conversion from digital to analog is still crappy, they become pretty pointless. I was hoping that sending out a digital signal and converting it just before sending it thorugh the original VGA cable could be a solution. It's weird there isn't something like a RetroTINK for old PC CRT monitors.

Now, I hope that audio switching isn't as problematic as video... Because I was thinking to hook up all the PCs to a nice Hi-Fi sistem, once I get sound cards for all of them.

Regarding KVM switches, I'd thoroughly recommend getting second hand old equipment, not new ones. Not only are they cheaper, but they were designed in an era when high-end computers still used VGA so users demanded quality. Aten and Belkin are generally the brands to watch, but Compaq also has some good stuff and even Avocent is decent. I've never paid more than EUR 25 for my KVMs, usually bought locally (in NL) via classified ads.

Not sure how the second hand market is in Italy, but failing classified ads there's always ebay (although I'd recommend trying to get one with good octopus cables included)

As for audio... decent switches aren't really a thing, plus inputs are guaranteed to be at differing levels, so what you really need is a mixer. I'm a fan of Behringer Eurorack Pro RX1602 mixers (with 8 stereo inputs)

Very happy with my adderview matrix. Anything from extron is also good

dionb wrote on 2025-02-06, 01:17:

Regarding KVM switches, I'd thoroughly recommend getting second hand old equipment, not new ones. Not only are they cheaper, but they were designed in an era when high-end computers still used VGA so users demanded quality. Aten and Belkin are generally the brands to watch, but Compaq also has some good stuff and even Avocent is decent. I've never paid more than EUR 25 for my KVMs, usually bought locally (in NL) via classified ads.

Not sure how the second hand market is in Italy, but failing classified ads there's always ebay (although I'd recommend trying to get one with good octopus cables included)

As for audio... decent switches aren't really a thing, plus inputs are guaranteed to be at differing levels, so what you really need is a mixer. I'm a fan of Behringer Eurorack Pro RX1602 mixers (with 8 stereo inputs)

I have no idea about the used market, didn't look a it yet. I live in a farly large city, so maybe I can find one not on ebay.
About the new ones, brand doesn't mean anything anymore? They started to cheap out now that VGA isn't the main standard anymore?
EDIT: I can still buy it off Amazon and return it if the quality isn't up to snuff.

An audio mixer isn't something I had considered, but I should've. A 3 or 4 channel one isn't even that expensive, especially if I plan to connect it to an Hi Fi system in the future. I won't need any kind of special equipment to connect the sound card to the mixer, right? It just works?

maxtherabbit wrote on 2025-02-06, 01:39:

Very happy with my adderview matrix. Anything from extron is also good

I'll add to the list. Do they make new ones? Are the new ones any good?

Mondodimotori wrote on 2025-02-06, 08:38:

[...]

I have no idea about the used market, didn't look a it yet. I live in a farly large city, so maybe I can find one not on ebay.
About the new ones, brand doesn't mean anything anymore? They started to cheap out now that VGA isn't the main standard anymore?

Exactly. Anyone needing quality display output will have been using digital transmission for 20 years now. So who still needs VGA? People managing that one old box that does something special (usually involving either custom software that won't run on new OSs or custom hardware that isn't supported in modern systems). The requirement is that you can see what's on screen, not much over that. Nobody is going to be spending the whole day every day using these things, or doing stuff that needs the output to be sharp. So it's a waste of money to make a KVM capable of crystal-clear display.

EDIT: I can still buy it off Amazon and return it if the quality isn't up to snuff.

You could, but I'm pretty sure it will be a disappointment. Far better to go for a device made around 2000 when VGA was mainstream, resolutions were getting a lot higher and so analog image quality really mattered.

An audio mixer isn't something I had considered, but I should've. A 3 or 4 channel one isn't even that expensive, especially if I plan to connect it to an Hi Fi system in the future. I won't need any kind of special equipment to connect the sound card to the mixer, right? It just works?

Nothing more than cables that fit the card(s) and the mixers. The RX1602 has 2x 6.3mm mono inputs, most sound cards have 3.5mm jacks, so I mainly have those cables, with 2x 6.3mm mono to 2x RCA for a couple of sound cards and modules with those outputs.

dionb wrote on 2025-02-06, 09:25:

Exactly. Anyone needing quality display output will have been using digital transmission for 20 years now. So who still needs VGA? People managing that one old box that does something special (usually involving either custom software that won't run on new OSs or custom hardware that isn't supported in modern systems). The requirement is that you can see what's on screen, not much over that. Nobody is going to be spending the whole day every day using these things, or doing stuff that needs the output to be sharp. So it's a waste of money to make a KVM capable of crystal-clear display.

dionb wrote on 2025-02-06, 09:25:

You could, but I'm pretty sure it will be a disappointment. Far better to go for a device made around 2000 when VGA was mainstream, resolutions were getting a lot higher and so analog image quality really mattered.

Yeah, I took a look at italian websites that shows local listings, and found this, selling several items, including a KVM from "WE.COME" (?). 10€, but it's provided without cables. So, let's add up: One power supply, three high quality VGA cables, three quality PS/2 combo cables for mouse and keyboard... Yeah prices starts to rank up for a unit wich I don't even know if it's an early 2000 quality one. Others I found were all from D-Link... Are they any good? I've found this thread still on Vogons, OP seems happy.
And I'm not even that in need for PS/2 switching. I can just pick up another two K/M PS/2 combos and just keep them under the desk, pulling them out when I need them. As far as I've understood, these switches are made with multitasking in mind, using all computers at the same time. I won't be doing that.

dionb wrote on 2025-02-06, 09:25:

Nothing more than cables that fit the card(s) and the mixers. The RX1602 has 2x 6.3mm mono inputs, most sound cards have 3.5mm jacks, so I mainly have those cables, with 2x 6.3mm mono to 2x RCA for a couple of sound cards and modules with those outputs.

That's great to know. Now, I'll also want to use at least one of my machine for CD Music, so I'll probably put more money on the table and get me a stereo mixer. Maybe I'll ask some of my musicians friends if they have some old units they wanna get rid of.

dionb wrote on 2025-02-06, 01:17:

...but Compaq also has some good stuff...

U mean this server stuff?

Have you ever handled one of those? Do they require any kind of special software?
But, most importantly, why should they provide high quality VGA output? It's not like you need that high quality on your console to handle the server, right?
Becuase I found a couple of them "locally" for a decent price, with all cables included.

I used to have a Compaq KVM, it was really good, although the controls were a bit of a pain (used smartkey instead of buttons, when you powered it up, it gave you a GUI...). Check the manual for the model for how it works and see if that would be OK for you.

And why decent quality? Because Compaq also made high-end graphical workstations, and because they regularly over-engineered a lot of stuff like this. Beige Compaq generally (leaving out awful Presarios) meant solid quality. And again, in this era people who wanted quality (and were prepared to pay the then premium for Compaq's professional line) also used VGA.

I can confirm everything dionb said. I have owned and tested many KVMs, old and new supposedly "high end" ones, and settled for an HP server KVM (af611a) that I recovered from a previous job, including original VGA/USB and VGA/2xPS2 cables and it's hands down the best one I've ever used. VGA is crisp and responsive and even using a Microsoft Intellimouse Explorer 3.0 with an USB-PS2 adapter on the KVM itself feels amazing. I'm using PS2 rate to push the mouse resolution to 200Hz in Win98 and I'm playing fps with 0 input lag and great picture.

Why those server KVMs? dionb already covered it but bottom line, they weren't gadgets - they were targeted to people that would literally spend hours if not days using them in front of a server rack with a rackable TFT7600 monitor. I was one of them. It was a work tool, we expected quality and it had the price tag to match.

Tiido wrote on 2025-02-05, 14:21:

Only pro stuff does a good job switching the VGA signal from my experience. I use an Extron MVX84 VGA matrix for my switching needs (1920 x 1440 and higher resolutions, which it handles perfectly), but only because I paid very little money for one.

Are the Extron MVX built equal? I can find a number of Extron MVX44s for around $40 USD on fleabay.

MV44 should be basically same inside as MV84 and 88, just with less connectors installed and slightly different firmware. When I looked inside mine, it has room for all the extra outputs but without them or the support components soldered on. It'll definitely be good.

dionb wrote on 2025-02-07, 18:01:

I used to have a Compaq KVM, it was really good, although the controls were a bit of a pain (used smartkey instead of buttons, when you powered it up, it gave you a GUI...). Check the manual for the model for how it works and see if that would be OK for you.

And why decent quality? Because Compaq also made high-end graphical workstations, and because they regularly over-engineered a lot of stuff like this. Beige Compaq generally (leaving out awful Presarios) meant solid quality. And again, in this era people who wanted quality (and were prepared to pay the then premium for Compaq's professional line) also used VGA.

Good then, I found one for less than 30€ with shipping, a Compaq EO1004A 4X, with cables and everyithing working. Found the manual, and yeah, you need hotkeys on the master keyboard to bring up the OSD and switch computers on the go. I haven't read yet if you need to switch when only one machine in powered on, or it just shows the first machine it get a signal from. I may actually connect a M/K combo to every PC and one just for the KVM, if I actually have space, but reading from others, I guess lag or M/K issues are basically nonexistent (and I hope they are, it would've been extremely frustrating to have input problems while working on a live server).
The seller wasn't able to tell me if and how much does the video degrade over the KVM, but I guess that's a subjective things . I could've even lived with the softness of that crap I got off Amazon, so anything better for a cheap price is good.

Boohyaka wrote on 2025-02-07, 19:29:

I can confirm everything dionb said. I have owned and tested many KVMs, old and new supposedly "high end" ones, and settled for an HP server KVM (af611a) that I recovered from a previous job, including original VGA/USB and VGA/2xPS2 cables and it's hands down the best one I've ever used. VGA is crisp and responsive and even using a Microsoft Intellimouse Explorer 3.0 with an USB-PS2 adapter on the KVM itself feels amazing. I'm using PS2 rate to push the mouse resolution to 200Hz in Win98 and I'm playing fps with 0 input lag and great picture.

Why those server KVMs? dionb already covered it but bottom line, they weren't gadgets - they were targeted to people that would literally spend hours if not days using them in front of a server rack with a rackable TFT7600 monitor. I was one of them. It was a work tool, we expected quality and it had the price tag to match.

Yup, I've checked old listings for new units, and the prices are up to snap for professional equipment.

dionb wrote on 2025-02-07, 18:01:

I used to have a Compaq KVM, it was really good, although the controls were a bit of a pain (used smartkey instead of buttons, when you powered it up, it gave you a GUI...). Check the manual for the model for how it works and see if that would be OK for you.

And why decent quality? Because Compaq also made high-end graphical workstations, and because they regularly over-engineered a lot of stuff like this. Beige Compaq generally (leaving out awful Presarios) meant solid quality. And again, in this era people who wanted quality (and were prepared to pay the then premium for Compaq's professional line) also used VGA.

Well, got myself a Compaq KVM and it arrived today. Payid less than 30€ with all cables and shipping.
Following the manual, I connect the unit and, glory, it works and, after booting the PC, it even looks good! Then I hear a noise.

Then I smell burning.

OH GOD.

I rush to disconnect everything from power and... I see smoke coming out of the KVM.

They warned me about old PSUs... They warned me about old capacitors on old MOBOs... No one ever warned me against KMVs, 🤣.

Just a short video of the aftermath (may be NSFW for some people sensible to old tech smoking)

PS: Luckly no PCs or Monitors were harmed in testing the unit.

Maybe it has a case of RIFAs...

Tiido wrote on 2025-02-21, 22:00:

Maybe it has a case of RIFAs...

Yeah... I'll probably propose the seller a partial refund, because it came with all the cables, and they are good quality cables, so they can be used with other KVMs... I payid very little for it, new cables alone would cost more.

Just... It's a dang shame it blew after a few seconds. The video really looked as crisp as direct connection, and it even seemed very easy to use.

I like using Belkin KVM's that switch sound because that makes life easier. Every model will have bandwidth specifications and that will let you know what the maximum resolution it can do.

For example:
https://www.newegg.com/belkin-f1ds104u-d-sub/ … N82E16817107303

You need to use the OEM cables or hope the aftermarket ones are shielded enough to work at those high resolutions.

Also beware many KVM's meant for industrial use have custom cables that are impossible to find now.

I stocked up on Analog KVMs and cables ages ago when they were dirt cheap.

Currently I am using a few Belkin SOHO that have DVI for video and had one blow a power chip. The 1A power wall-warts seemed to like blowing capacitors so I used 2A ones and all is well.

Unknown_K wrote on 2025-02-22, 02:49:

I like using Belkin KVM's that switch sound because that makes life easier. Every model will have bandwidth specifications and t […]
Show full quote

I like using Belkin KVM's that switch sound because that makes life easier. Every model will have bandwidth specifications and that will let you know what the maximum resolution it can do.

For example:
https://www.newegg.com/belkin-f1ds104u-d-sub/ … N82E16817107303

You need to use the OEM cables or hope the aftermarket ones are shielded enough to work at those high resolutions.

Also beware many KVM's meant for industrial use have custom cables that are impossible to find now.

I stocked up on Analog KVMs and cables ages ago when they were dirt cheap.

Currently I am using a few Belkin SOHO that have DVI for video and had one blow a power chip. The 1A power wall-warts seemed to like blowing capacitors so I used 2A ones and all is well.

Yup, I actually plan to keep the cables that came with the Compaq unit that went up in smoke. I only saw a few seconds of video output, but it looked good.