Power-On Self-Test (Post); What Does The Post Check For You - Acer Veriton 3000 Service Manual

Power-on Self-Test (POST)

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 the 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.

What does the POST check for you ?

The main components on the main board that are diagnosed and/or initialized by the POST to ensure system
functionality are as follows:
Microprocessor with built-in numeric co-processor and cache memory subsystem
Direct Memory Access (DMA) controller (8237 module)
Interrupt system (8259 module)
Three programmable timers (system timer and 8254 module)
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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