There are myriad styles of keyboards for desktop PCs: wired and wireless; extra media keys; built-in trackballs; ergonomic split keyboards; spill-resistant and industrial rated. Ranging in price from USD $10 to $150, there is a difference (see premium keyboard). PC keyboards also work on the Mac.A Keyboard ComedySince the IBM PC debuted in 1981, there have been four standard keyboard layouts, each one rearranging commonly used keys that annoy users to this day. For example, the Control key, used extensively in word processing, was originally easy to reach, only to be moved to an awkward location (see Control key).PC - AT - Enhanced - WindowsUndersized Enter and left Shift keys on the original IBM PC keyboard were corrected on the IBM PC AT's keyboard, but it had a smaller Backspace key (see PC/XT keyboard and AT keyboard). The subsequent Enhanced keyboard fixed the Backspace key but relocated Control, Alt and function keys (see Enhanced keyboard). That was superseded by the Windows keyboard, which only added function keys, and desktop PC keyboards today use this last layout (see Windows keyboard).From DIN to USBThe first PC keyboards connected via 5- and 6-pin DIN plugs, which were replaced by USB. During the transition, third-party keyboards came with USB-to-DIN adapters. See legacy port and DIN connector. For all the keyboard entries in this encyclopedia, see keyboard.