Power-On Self-Test

                    ┌─┐     ┌─┐  ┌─┐    ┌─┐
                    │P│ower─│O│n │S│elf─│T│est
                    └─┘     └─┘  └─┘    └─┘
 The POST is a ROM program that's executed when the computer is first
 turned ON.  It performs the following functions:

  ■ Checks the Switch Settings (PC,XT) or the CMOS Memory (AT,PS/2) to
    determine what peripheral equipment is connected and sets the
    Equipment List bit flags.

  ■ Checks RAM and writes data to all addresses (required for RAM error
    detection) and tests components (DMA, interrupt, disk, keyboard, etc.).
    It beeps and/or displays error codes; see POST Error Codes.

  ■ Performs ROM-Scan to install add-on firmware and initialize add-on
    hardware.

  ■ Executes the bootstrap sequence to load DOS.

  ■ Checks CMOS address 0fH (and 40:0072 in the BIOS Data Area) for special
    actions.

See Also: System Startup Sequence
          ROM-Scan
          CONFIG.SYS
          MultiConfig Menus
          DoubleSpace
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