Why Do Motherboards Still Have PS2 ?

The PS/2 port on modern motherboards can seem like little more than an antiquated annoyance.

I mean we’ve had USB for over a decade now, and the power of the ATX connector ensures that even if you need to splice in a new peripheral onto your rig, you can rest assured that it’ll be compatible with the power supply. But PS/2 ports are still ubiquitous on everything from server boards to micro-ATX.

PS/2 port Vs USB

PS/2 port provides a level of signal quality that USB just can’t match. In fact, PS/2 ports have been around since IBM designed them as an alternative to its proprietary 25-pin “keyboard” connector on 1981’s IBM PC/AT. In addition to giving the fledgling PC industry the chance to develop a more open standard, the PS/2 also gave IBM an opportunity to improve on its previous keyboard connector.Motherboards Have PS2

While that proprietary connector allowed for IBM’s April 1981 Advanced Keyboard* (which included cursor keys and function keys), it was also rather fragile – which led to frequent failures over time. The new connector would stand the test of time, while also supporting advanced features like plug-and-play detection and individual keystroke-level input.

PS2 After Microsoft Released

It was only after Microsoft released Windows 95 that USB really started catching on as a primary interface on PC motherboards, but even then PS/2 ports were offered alongside them in case you might need them at some point down the road. And if you’re reading this, chances are you do.

While USB can provide many of the same conveniences that PS/2 does (keyboard and mouse integration, plug-and-play detection) it still lacks the high-quality signal transfer that PS/2 is capable of. For anyone who’s ever used a dirty keyboard with a USB port, then tried to remove said dirt by blowing on it – only to have their keystrokes fail – they’ll understand why this matters.

Benefits Of PS2

The biggest practical benefit to having both PS/2 and USB ports on your motherboard is convenience. If you’re building or upgrading a very old PC, there’s a good chance there aren’t any free USB ports in reach for connecting peripherals like mice and keyboards while the system is still running. In that case, PS/2 ports are necessary to keep your system booting up properly.

In cases where you’re adding a brand new peripheral, though – say a wireless mouse – having USB ports around can make it much easier to install the dongle in an out of sight (or unreachable) port.

And while less common these days, there are still some older devices that require the cabling of a serial-port-based accessory like a modem or router. The same goes for FireWire, although high-quality adapters exist for converting FireWire to USB 3.0 – so in most cases, this isn’t really an issue anymore either.

Nevertheless, the main reason why many motherboards still come equipped with PS/2 ports is that they’re an easy way for manufacturers to cut costs. After all, if you’re looking at using the same chipset on multiple boards – or even worse, using a cheaper version of an older chipset that isn’t as widely used anymore – they might not have any free USB ports available to them and therefore need something else to drive their keyboard and mouse.

PS/2 is Cheap

In those cases, it’s far easier (and much less costly) for a company to just slap in some legacy ports from a supplier like Atrox than figuring out how to integrate both USB and PS/2 into one chip. And besides who needs built-in wifi when you can add another stick of RAM instead, right?

The PS/2 port has been around since 1981 and will likely continue to be a part of at least some motherboards for the next few years yet. Whether or not it finds its way onto Intel’s 100-series chipsets is anyone’s guess right now – but chances are that they’ll probably be included on future products from other manufacturers as well. It just makes good business sense.

An Interesting Footnote

Windows 95 only supported simple text input in DOS mode (and therefore IBM’s Advanced Keyboard), so Microsoft had little choice but to either support the new keyboard design or lose compatibility with most Windows programs. Instead, it released a free driver manager which offered users a choice of which keyboard to use in-program – and thus became the first operating system to support multiple keyboards at once.

I call bullshit on that reason why motherboards still have a PS2 port the same USB port can be used with a serial adapter. That whole last paragraph goes over my head. I agree with some added convenience for newer devices and drivers, but not all these extra ports.

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