Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

PS/2 interface has existed since Windows 95 (that I can remember) and, while all another interfaces were upgraded (USB, USB2, USB3, …) or just died (such as Parallel, and the large one used for keyboards), most desktops came with a PS/2 connector until recently. Newer ones, such as USB, HDMI, FireWire, and others are just born being plug-and-play. However, PS/2 follows the same specification from more than 10 years ago (someone correct me if I am wrong) and it doesn't seems to change in a few years.

Today this is the only non-plug-and-play interface that I can remember, so there is some reason for that? What determines if a interface is or isn't plug-and-play?

share|improve this question
1  
Same reason there was no sliced bread before there was. ;-> –  Moab Feb 11 '12 at 2:18
    
What about RS-232 (still lives since 1962 and is not PnP), VGA DE-15 connector (still lives since 1987 and is not PnP)? So PS/2 is far not the only non-PnP interface that is widely used today. –  Andrey Regentov Apr 12 '13 at 5:20

3 Answers 3

up vote 3 down vote accepted

The PS/2 interface dates from 1987. So it's a 25 year old interface, predating any plug and play OS.

One reason it's around is inertia; there's still a lot of PS2 peripherals out there. Another advantage is its simplicity - I don't need a lot of complexity in my BIOS to read a PS2 keyboard. I have a wireless USB keyboard on my old Windows PC and it takes me forever to get into the BIOS Settings to make changes. Sometimes I wish I had a PS2 keyboard to make BIOS setting easier.

share|improve this answer

I can unplug and plugin my ps/2 keyboard whenever i want to.At least with Linux specifically latest Lubuntu prerelease.

When I plug it in its lights flash (like during computer booting) and works as before.

share|improve this answer

PS/2 has improved since it was first introduced, although not drastically.

At the end of the day, USB and many other interfaces are designed for input/out and get faster as the standard improves and as the technology evolves.

PS/2 was designed for keyboards/mice and nothing else, there just isn't really a need to improve the technology.

That being said, A lot of modern motherboards to support plug and play PS/2 - I know that the machine I am using at the moment allows me to plug and unplug PS/2 devices when the machine is on without problems. It really depends on the chipset and other factors of the motherboard.

share|improve this answer
2  
You’re probably confusing PnP with hotplug. PS/2 is not hotplug and will never be, because it uses ISA signals. You should not unplug PS/2 mice and keybords while the machine is running. –  kinokijuf Feb 10 '12 at 17:30
    
@kinokijuf Honestly, you are correct, I think I am mixing them up, but, doesn't plug and play mean, plug it in and it works... so, what is the difference to hot-plugging? I have plugged/unplugged loads of times on my machine - I used to do it many times to switch between a laser pointing presenter mouse and a regular one and never saw a problem. –  William Hilsum Feb 10 '12 at 20:08
1  
According to Microsoft Michael Kaplan, keyboards are plug-and-play, but not plug-and-communicate-what-they-look-like. And hot-plug means that you can connect the device while the comp is running. PS/2 does not have that (try this at home: start computer up without a mouse, connect a PS2 mouse and observe that the computer does not see the mouse). –  kinokijuf Feb 10 '12 at 20:28
    
It worked because both devices look probably like a generic „Microsoft PS/2 mouse” or something like that. –  kinokijuf Feb 10 '12 at 20:30

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.