![]() ![]() ![]() ![]() For example, a particular US keyboard's QWERTY keys will function but the Calculator and Logoff keys will not because they are defined on Usage and cannot be reported in boot protocol. Buttons, knobs and keys that are not reported on Usage are not available. Many systems also support additional keys on basic western European 105-, Korean 106-, Brazilian ABNT 107- and Japanese DOS/V 109-key layouts. Most systems support all 104 keys on the IBM AT-101 layout, plus the three extra keys designed for Microsoft Windows 95 (the left and right Windows key, and the Menu key). Keyboard – Any of the first 256 key codes ('Usages') defined in the HID Usage Tables, Usage can be reported by a keyboard using the boot protocol, but most systems only handle a subset of these keys.The only devices supported in boot protocol are However, the benefit is that minimal functionality is still possible on hosts that otherwise would be unable to support HID. The HID descriptor is not used in this mode so innovation is limited. In boot protocol, only specific devices are supported with only specific features because fixed data packet formats are used. Because it was understood that not all hosts would be capable of parsing HID descriptors, HID also defines 'boot protocol'. The above mechanism describes what is known as HID 'report protocol'. ![]()
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