Using One Keyboard for Two Computers: DIY Switches and Affordable Electronic Alternatives

I often repair computers at home and I don't have enough space and funds to work from one desk. I have already connected the signal concentration from 2 computers to one monitor, I bought a monitor with 2 inputs and a switch on the front I have 2 mice, which is not a problem because they are cheap and do not take up much space. The biggest problem is with the keyboard, I did not find a device on the Internet that could be used here, any distributors, switches, etc .... so I had to come up with something (need is a mother of ideas)

I am addressing you with a problem
1. whether to make a switch (very simple) for each pin of the plug, i.e. for each wire of the cable, insert a switch into the keyboard, or insert a coupled switch (several independent switches coupled together).

2 or some electronic alternative maybe on relays or something else

3 well, unless someone knows where you can buy such a contraption inexpensively, it will solve my problem

thank you in advance and best regards

nelik1987

Such switches are KVM, look on the Allegro, they switch Keyboard + mouse + monitor and simulate connecting these devices even when working on a second computer. Electronic are the best (generally better than mechanical).

if you like to play, I recommend one multipolar switch (a separate pole for each wire). Then you switch the keyboard to the corresponding PC with one switch. There will always be a little penny left in your pocket

I know that there is such a thing, but I mean only about ps2, and spending PLN 60 is a bit of a lot to translate only 1 thing ...

Somewhere, once upon a time, I found a wiring diagram, a few keyboards, but the idea is important.
Schematic attached in the appendix It is not of a quality, but it is legible.

in general, mechanical switches have the disadvantage that the computer does not always function properly when the keyboard or mouse switches it. Electronic and KVM switches keep the port state and don't make the computer go dumb.

http://allegro.pl/show_item.php?item=71645182
http://allegro.pl/show_item.php?item=70826001
http://allegro.pl/show_item.php?item=70621805
http://allegro.pl/show_item.php?item=70710406
...

micro
I admit that this solution is like a steam engine used to extinguish a candle
nelik1987
Solder the usual Isostat and after the pain. First of all, it is cheap and takes up little space.

Probably, but .. "but the idea is important" .
After all, it does not have to use the entire system.

nelik1987 wrote:

I have 2 mice, which is not a problem because they are cheap and do not take up much space. The biggest problem is with the keyboard, I did not find a device on the Internet that could be used here, any distributors, switches, etc.

nelik1987 wrote:

I know that there is such a thing, but I mean only about ps2, and spending PLN 60 is a bit of a lot to translate only 1 thing ...

No offense, but if you can afford 2 mice, why not 2 keyboards?
You can buy a new one for a dozen or so zlotys.
I believe that another solution will be more complicated ...

"but the idea is important"

greetings
HenryK3

I know that you can buy a keyboard 2 what the mouse is 2 are recycled, i.e. for free, as almost always, we are looking for ways to solve the problem as cheaply as possible because who now has excess money :D

the problem with the keyboard is that I don't have a place to put it anymore and I wanted to prepare a computer repair station well

one could experiment a little with the diagram thrown in by "micro" - remove the "From the mouse" part, and add a 4066 system connecting to the computer, which at the moment does not work with our keyboard, electronics from some old, mechanically worn keyboard, so that the PC "does not stupid ".... it will fit in the housing of this switch. Isostat would be the most convenient, but will this fraction of a second when switching, when none of the computers can see the keyboard, negatively affect their operation ?? worth checking out.

Hello!
... I used the isostat as a switch for two PCs and an Amiga for several years and never had any problems.
So I recommend this solution as the cheapest and proven!

I did not want to read half of these posts because they are nonsense if you want to have a keyboard on the switch, you can do it so that you connect the switch to data + and data- and outputs for 2 computers, but I also have a great philosophy. and if you want to do so that, for example, when one computer is turned on and the other is turned off, the keyboard automatically switches to the turned on, then you have to use one relay

Moderated By TONI_2003:

Please tone down your statements because they will go to the trash, and maybe something more!

wader_669 wrote:

I did not want to read half of these posts because they are nonsense if you want to have a keyboard on the switch, you can do it so that you connect the switch to data + and data- and outputs for 2 computers, but I also have a great philosophy. and if you want to do so that, for example, when one computer is turned on and the other is turned off, the keyboard automatically switches to the turned on, you have to use one relay

Thank you, omniscient, maybe there is a schematic or something like that, because it's not so default for everyone and will not know how to connect this relay and how to connect it all, if the rest of the cables are connected to both systems, so I know but can + etc also be permanently connected without a switch ??

Wader- I VERY dislike your answer in this topic ... If you ask for something, I will also answer you this way - even though you are right.

As for the topic, according to: http://www.hardwarebook.net/connector/userinput/keyboardpc6.html

You just need to switch pin 1. (data) and if it doesn't work, please also switch pin 5. (clock) - The rest of pins (3,4 and 6) should be closed permanently.

greetings
Darek

As SanceS writes, it is enough to switch DATA and CLOCK, the lines disconnected from the computer side (i.e. the one from which the keyboard is currently disconnected with the switch) should be pulled up to + 5V by resistors (about 10k per eye)

Important thing - computers cannot be started simultaneously, because one of them will not detect the keyboard, first you have to wait for one to start, and then switch the keyboard and start the other one.

What wader_669 writes will work, but with a USB keyboard ... :P

By the way, I gave 3PLN for the PS / 2 socket, you need two + isostat from 2-4PLN + 3PLN plug => 11PLN.
The company's keyboard (no matter what, it is important that it works, I will tell you that on the M ) costs 11PLN.

Shg - you are right the keyboard costs 11 zlotys (or 19 zlotys there ...) but as the founder of the topic wrote -> there is no room on the desk anymore. Besides, working on two keyboards and mice makes me nervous (I'm always wrong and rummaging around the cables, because it seems to me that something has broken off) :D

I will give the second letter of the company: e - it is a two-part word

I do not agree that my solution will only work on a usb keyboard. Ps / 2 has 4 lines in total gnd, 5v and data +, data- the same is in usb, that's why these ps / 2 and usb adapters are so cheap because there is no system there, it is just an ordinary adapter. I might be wrong with this ps / 2 connection but I think I'm speaking well

wader_669: where do you have data + and data- on your PS / 2 keyboard?
such things are only in usb ...

The second letter is "a". "Stingray" in English.

And PS / 2 USB adapters are so cheap, because they are mass produced. DIN miniDIN adapters are even cheaper and these do not contain any electronics.

I don't see the data + and data- lines here:
http://www.hardwarebook.net/connector/userinput/keyboardpc6.html

However, the omniscient friend Wader made a mistake, in ps2 we have one date line ...

Nelik1987- and how did you make the switch?

okay, I'm a robot and they programmed me wrong. now serjo I do not know that usb is data + and data- no I thought it is similar to ps / 2, in this case there is no difference whether it is data- + or clock. as earlier post I offended someone, sorry you know everyone has a bad day, and the more that I write half the posts at night and barely alive. well, but you have to admit that for such a simple thing, someone exaggerated such a scheme

hmmm, so far I have not done anything all the time I have your posts but it comes out that it will not be so complicated because it is impossible to make 6 switches as I thought but it is enough to make 2 switches. So far, there is a 2nd keyboard on the monitor but I don't want it to be like that in the future, if I invent something, I will present it

thank you for any replies

Well hehe, as someone wrote .... you can extinguish a candle with a steam engine - why not :D

Wader - I think you lifted yourself unnecessarily.

And if data- and Clock are the same, I would argue ... :D

greetings

I also have a question. Does such a KVM device support a wireless keyboard and mouse set (for 1 USB) or do you need a PS / 2 adapter or maybe you need to buy a separate keyboard and mouse? The kit is A4Tech KBS-2680RP. Or maybe there are devices that switch monitors and USB sets ???

Gentlemen, of course, you can unpin the signals from the mouse or keyboard. But what the effect will be depends on the motherboard. I have seen cases where removing the plugs from the keyboard and mouse and reinserting it did not change anything. In other cases, after reconnecting one or both of the devices stopped working.

Generally, in the mouse, we should leave all connections and disconnect CLOCK, giving the signal from the generator to the CLOCK input of the mouse. In the case of the keyboard, leave all connections and cross the DATA, and give the substitute signal to the DATA input in the keyboard socket on the motherboard.

The replacement signal can be used from the mouse socket on the board (CLOCK) after passing it through a monoflop with a pulse time of about 100us.

Maybe I'm wrong, if that's the case then correct me.

and as always it turns out that it is best to buy a ready-made device, it is almost always cheaper because the masses are very cheap and buying individual parts is very expensive so I bought a used device works well the only downside is that it is passive and has a large switch but I plan to buy one I saw a nice little on the Allegro for 60, it pays off, it's not worth doing it yourself, such decisions about building some devices yourself need to be carefully thought over