Acer power sx/sxb/sc manual Power-On Self-Test Post

Power-On Self-Test (POST)

Each time you turn on the system, the Power-on Self Test (POST) is initiated. Several items are tested during POST, but is for the most part transparent to the user.

The Power-On Self Test (POST) is a BIOS procedure that boots the system, initializes and diagnoses the system components, and controls the operation of the power-on password option. If POST discovers errors in system operations at power-on, it displays error messages on screen, generates a check point code at port 80h or even halts the system if the error is fatal.

The main components on the main board that must be diagnosed and/or initialized by POST to ensure system functionality are as follows:

!Microprocessor with built-in numeric co-processor and cache memory subsystem

!Direct Memory Access (DMA) controller

!Interrupt system

!Three programmable timers

!ROM subsystem

!RAM subsystem

!RTC RAM subsystem and real time clock/calendar with battery backup

!Onboard serial interface controller

!Onboard parallel interface controller

!Embedded hard disk interface and one diskette drive interface

!Keyboard and auxiliary device controllers

!I/O ports

!PS/2-compatible mouse port

!PS/2-compatible keyboard port

!Serial ports

!Parallel ports

!USB port

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