In the world of computer peripherals, keyboards are an essential input device that allows us to interact with our computers. Two types of keyboard interfaces have been widely used over the years: HID (Human Interface Device) Keyboard Device and Standard PS/2. In this write-up, we'll explore what these terms mean, their differences, and how they work.
HID USB keyboards use a polling-based system. The CPU periodically "asks" the USB controller if any keys have been pressed. While modern polling rates are incredibly fast (often 1000Hz or once every millisecond), there is a microscopic delay compared to the direct interrupt of a PS/2 device. Additionally, older USB keyboards were often limited to "6-Key Rollover," though modern gaming USB keyboards have largely overcome this limitation through software. Why Do I See Both in Device Manager? what is hid keyboard device and standard ps/2
Unlike USB keyboards, true PS/2 keyboards are not typically hot-swappable. If you unplug a PS/2 keyboard while the PC is on, the computer may not recognize it when you plug it back in until you perform a full reboot. Key Differences Between HID and PS/2 In the world of computer peripherals, keyboards are
While they both do the same job (turning keystrokes into text on your screen), they function differently under the hood. HID USB keyboards use a polling-based system
This guide explains two of the most common methods computers use to communicate with keyboards: the and the Standard PS/2 Keyboard .