Keyboard layout based on the Wijesekara typewriter for Sinhala script. The Chinese National Standard on Tibetan Keyboard Layout standardises a layout for the Tibetan language in China. The first version of Microsoft Windows to support the Tibetan keyboard layout is MS Windows Vista. The layout has been available in Linux since September 2007. Mac OS-X introduced Tibetan Unicode support with OS-X version 10.5 and later, now with three different keyboard layouts available: Tibetan-Wylie, Tibetan QWERTY and Tibetan-Otani. The Bhutanese Standard for a Dzongkha keyboard layout standardizes the layout for typing Dzongkha, and other languages using the Tibetan script, in Bhutan. This standard
QWERTY Edison's 1872 electric print-wheel device which later became the basis for Teletype machines; Lucien Stephen Crandall's typewriter (the second to come onto the American market) whose type was arranged on a cylindrical sleeve; the Hammond typewriter of 1887 which used a semi-circular "type-shuttle" of hardened rubber (later light metal); and the Blickensderfer typewriter of 1893 which used a type wheel. The early Blickensderfer's "Ideal" keyboard was also non-QWERTY, instead having the sequence "DHIATENSOR" in the home row, these 10 letters being capable of composing 70% of the words in the English language. Alternating hands while typing is a desirable trait