Human interface device

A human interface device or HID is a type of computer device usually used by humans that takes input from humans and gives output to humans. The term "HID" most commonly refers to the USB HID specification. The term was coined by Mike Van Flandern of Microsoft when he proposed that the USB committee create a Human Input Device class working group. The working group was renamed as the Human Interface Device class at the suggestion of Tom Schmidt of DEC because the proposed standard supported bi-directional communication. The HID standard was adopted primarily to enable innovation in PC input devices and to simplify the process of installing such devices. Prior to the introduction of the HID concept, devices usually conformed to strictly defined protocols for mouse, keyboards and joysticks; for example, the standard mouse protocol at the time supported relative X- and Y-axis data and binary input for up to two buttons, with no legacy support. All hardware innovations necessitated either overloading the use of data in an existing protocol or the creation of custom device drivers and the evangelization of a new protocol to developers. By contrast, all HID-defined devices deliver self-describing packages that may contain any number of data types and formats. A single HID driver on a computer parses data and enables dynamic association of data I/O with application functionality, which has enabled rapid innovation and development, and prolific diversification of new human-interface devices. A working committee with representatives from several prominent companies developed the HID standard. The list of participants appears in the "Device Class Definition for Human Interface Devices (HID)" document. The concept of a self-describing extensible protocol initially came from Mike Van Flandern and Manolito Adan while working on a project named "Raptor" at Microsoft, and independently from Steve McGowan, who worked on a "SIM" project that defined a device protocol for the VFX1 VR Headset and its peripherals based on ACCESS.