计算机编码
这个表格强调了这篇文章的主题：位就是位。这样的话，您可以使用位来表示字符。您可以把特殊的代码描述成特殊的十进制、八进制和十六进制，但是它们仍然是相同的代码。这些数值的表达，无论是十进制、八进制或十六进制，都只是相同的位的表达。
键盘扫描码
PS/2接口起的PC键盘支持最多三组扫描码集。最常遇到的是“XT”扫描码，它基于及更早的计算机使用的83按键键盘。其大部分由单字节组成，低7位标识按键，and the most significant bit is clear for a key press or set for a key release. Some additional keys have an codice_1 (or rarely, codice_2 or codice_3) prefix. These were initially assigned so that ignoring the codice_1 prefix (which is in the key-up range and thus would have no effect on an operating system that did not understand them) would produce reasonable results. For example the numeric keypad's Enter key produces a scancode of codice_8, which corresponds to the regular Enter key's scancode of codice_9.