Throwback tech: Taking a closer look at the original USB-to-PS/2 adapter

[Shawn Knight]

Editor's take: One of the first upgrades I bought for my very first computer around the turn of the century was a Microsoft IntelliMouse Explorer. Its standout feature was IntelliEye, an optical tracking system that replaced the traditional mouse ball and afforded unprecedented precision with minimal maintenance.

The pointer shipped with a then-standard PS/2 port but also worked with USB when using the included adapter. What you may not know is that this small, green adapter was purely a mechanical component.

As Microsoft's Raymond Chen recently explained, PS/2 and USB are completely different protocols that are not compatible in any way. The adapter simply connected one set of pins to another, but featured zero circuitry. Indeed, it was the mouse (or keyboard, or whatever other device you were trying to use) that did all the work.

Chen likened the adapter to those inexpensive electrical outlet adapters popular among international travelers. In those, the adapter just connects one set of prongs to a different standard. All of the "magic" happens in the appliance or the power brick you are attempting to use.

Note that this is true of the older, green adapters. New units are still being manufactured, although Chen is unsure if these feature any internal hardware that translates between the PS/2 and USB signaling protocols or if everything is still managed by the target device.

As for the IntelliMouse, Microsoft announced plans to create a modern version of the fan-favorite in 2017 and made good on the promise a few years later. A quick check of Microsoft's online store, however, shows the device is currently "out of stock." The same was true at Amazon and Best Buy, suggesting the device may have been discontinued.

For those set on picking one up – either a newer model or a vintage example, I was able to find several options available on eBay at prices that won't break the bank. Adapters are also readily available for a couple of bucks each.

Masthead credit: Marcus Urbenz

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Throwback tech: Taking a closer look at the original USB-to-PS/2 adapter

 

[nismo91]

I remember this very well. bought my first laptop 20 years ago. was a high school student back then, and at the time slim low profile keyboard from laptop wasn't really nice to use (still is, but I got used to it). my laptop doesn't have PS2 port so I had to find usb keyboard.

back then finding a usb keyboard is difficult. people were selling only PS2 keyboard. the only usb keyboard I could find were a kb+mouse combo which were much more expensive.

so I found a $8 logitech keyboard and $2 PS2 to USB adapter. bought them and it didn't work. I was curious about the adapter so everytime I had a friend with PS2 keyboard I would borrow it and test my adapter. no keyboard ever work with that adapter, so that's when I know it was a flop. that's when I knew why PS2 keyboard were cheap and USB keyboard were more expensive back then.

also worth mentioning at that time nearly all mice sold were usb mice, but sometimes they came with USB to PS2 adapter for those who want to free up a usb port in their motherboard. those adapters always work with mice it came with. but iirc it's not hot swappable aka you need to restart the computer if you just plugged it in.

so yes, I already knew the USB and PS2 were never interchangeable. it was a good riddance to be honest, and I'm quite sure no mainstream motherboard produced in the past 8 years has PS2 port anymore.

 

[Thrackerzod]

it was a good riddance to be honest, and I'm quite sure no mainstream motherboard produced in the past 8 years has PS2 port anymore.

Motherboards with PS/2 ports are still being made. My motherboard (ASUS Prime B650M) has one. New PS/2 optical mice are also still being made.

 

[yRaz]

Motherboards with PS/2 ports are still being made. My motherboard (ASUS Prime B650M) has one. New PS/2 optical mice are also still being made.

Basically all server equipment has a PS2 port on it

 

[TonyBony]

I was told the ps/2 keybord/mouse was the only way to install older generations of windows on a new gem motherboard, never worked for me with or without adaptor sadly. Back to the drawing board for my next legacy build.