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Chapter 4
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:
T
Microprocessor with built-in numeric co-processor and cache memory subsystem
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Direct Memory Access (DMA) controller (8237 module)
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Interrupt system (8259 module)
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Three programmable timers (system timer and 8254 module)
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ROM subsystem
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RAM subsystem
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RTC RAM subsystem and real time clock/calendar with battery backup
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Onboard serial interface controller
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Onboard parallel interface controller
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Embedded hard disk interface and one diskette drive interface
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Keyboard and auxiliary device controllers
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I/O ports
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PS/2-compatible mouse port
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PS/2-compatible keyboard port
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Serial ports
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Parallel ports
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USB port
Summary of Contents for Veriton 3000
Page 51: ...46 Chapter 2 ...
Page 52: ...20 Chapter 1 ...
Page 78: ...46 Chapter 2 ...
Page 96: ...64 Chapter 3 ...
Page 110: ...78 Chapter 4 ...
Page 116: ...84 Chapter 6 ...
Page 126: ...94 Chapter 6 ...
Page 128: ...96 Appendix A ...
Page 136: ...104 Appendix C ...