USB might be “Universal” but it has only existed since 1996, and it took a few years for USB peripherals to take over.
But take over from what exactly?
The venerable PS/2 port which had been the mouse and keyboard interface of choice for an entire decade before USB showed up on the scene.
Want to know more?
What is a PS/2 port?
The PS/2 port is a 6-pin connector mini-DIN connector invented by IBM all the way back in 1987.
It was created to be the default interface for the IBM Personal System/2 personal computers that were released at the same time.
Personal System 2 = PS/2.
Not very creative, but it got the job done and everyone began using the term.
Why did the PS/2 port become popular?
IBM created the first personal computer in 1981, pretty much creating the home computer industry.
Every other personal computer (PC) built that was not an IBM PC was referred to as a clone, and there were lots of them. In fact, that’s how companies like Dell and Gateway got started – cranking out IBM PC clones.
As IBM changed the technology used in their computers the clone manufacturers followed along, and that’s why the PS/2 interface is a good example of that.
Why is it called a “compatible” mouse?
The “compatibility” element of the PS/2 mouse name came from the fact that any mouse (or keyboard) that featured a PS/2 connection could be connected to any IBM PC or clone that had a PS/2 port.
This was also the first hint that some kind of universal connection port was required because before the PS/2 interface was launched there were multiple types of mouse ports and connections.
So, a mouse designed for one brand of computer probably would not work with another brand of computer – obviously very frustrating for computer owners.
PS/2 compatible mice have largely been replaced by USB mice in recent years, but they are still used in some older computers that do not have USB ports.
Are PS/2 mice redundant?
Oddly enough, the answer is “No” and probably not for the reason you expect i.e. people with older computers or in developing countries use whatever port they have on their computer.
But you can still buy PS/2 mice and keyboards online if you want to. This means there’s an ongoing demand for devices using this interface.
PS/2 keyboards and mice are also rumored to be popular with gamers.
Because they offer a dedicated connection port with:
- Lower latency (allegedly because of a better polling rate)
- No interference from other devices sharing the same data bus (USB)
PS/2 mice and keyboards also come into their own when working on much older computers because they don’t require drivers, unlike the USB controller on any modern computer.
Downsides of PS/2 compatible mice
The vast, vast majority of computers available right now have USB ports. In fact, you’re going to have to work pretty hard to find a computer or motherboard with PS/2 ports on it.
PS/2 compatible mice (meeses?) do not support hot-swapping.
Hot-swapping is the ability to plug and unplug a device from a computer while it is running.
So, if you unplug your PS/2 compatible mouse from your computer while it is running, you will need to reboot your computer for the mouse to work again.
That’s far from ideal.
So that’s a quick history of the PS/2 compatible mouse.
I hope you enjoyed it.
Featured image source: https://en.wikipedia.org/wiki/PS/2_port#/media/File:PS2_keyboard_and_mouse_jacks.jpg