HP Vectra Technical Reference Manual page 325

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Initialize the video display for diagnostic messages.
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Test the operation of the 80286.
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Test the system ROM.
~
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Test and initialize 8254 timer/counter and start the refresh counter.
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Test and initialize DMA controllers and DMA page registers.
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Test the first 64KB of system RAM.
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Test and initialize the 8259A interrupt controllers.
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Test the 8041 controller.
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Test the HP-HIL controller and link.
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Test CMOS RAM for integrity.
• Determine if manufacturing electronic tool is present, if so, run manufacturing test.
• Test the remaining base system RAM (RAM above the first 64KB.
• Test the extended RAM above memory address 1OOOOOH. (protected mode RAM.)
• Test the real-time clock portion of the RTC/CMOS chip.
• Test the flexible disc controller subsystem.
• Test the 80287 co-processor if present.
The power on self test performs tests on various sub-systems in the hardware when power is
switched on or when the system is reset. If a problem is detected, a
4
digit hex error code is
displayed. (In order for the code to be displayed, the video display adapter must be a multimode,
a monochrome, or a color adaptor.) These codes are listed in table 10.2.
POST then compares the configuration information stored in the CMOS memory with the actual
system. If a discrepancy is found, a message will be displayed instructing the user to run the
SETUP utility. For example, if the CMOS memory indicates two flexible disc drives present, but
the system contains only one, the message will be displayed.
316 System Processes