Legacy-free PC Legacy-free PC A legacy-free PC is a type of personal computer that lacks a floppy drive, legacy ports, and an Industry Standard Architecture (ISA) bus (or sometimes, any internal expansion bus at all). According to Microsoft, "The basic goal for these requirements is that the operating system, devices, and end users cannot detect the presence of the following: ISA slots or devices; legacy floppy disk controller (FDC); and PS/2, serial, parallel, and game ports." The legacy ports are usually replaced with Universal Serial Bus (USB) ports. A USB adapter may be used if an older device must be connected to
Serial port code. Many settings are required for serial connections used for asynchronous start-stop communication, to select speed, number of data bits per character, parity, and number of stop bits per character. In modern serial ports using a UART integrated circuit, all settings are usually software-controlled; hardware from the 1980s and earlier may require setting switches or jumpers on a circuit board. One of the simplifications made in such serial bus standards as Ethernet, FireWire, and USB is that many of those parameters have fixed values so that users cannot and need not change the configuration; the speed is either fixed or