1/15 POST Operation

MIS-B200-01Spring 99

Agenda for 1/15

• roll call• discussion of POST• handing out of group memberships• discuss plans for Wednesday, 1/20/99

Agenda for 1/15

• roll call• discussion of POST• handing out of group memberships• discuss plans for Wednesday, 1/20/99

From the CD-ROM: Tour the Boot-up Process

POST: Power-On Self-Test, step 1Step 1~ 5 Volts is sent

to the CPU, deleting any old data in the internal memory registers.

Power-On Self-Test, step 1AStep 1A: The

voltage also resets the program counter to the address of the next command that the CPU will execute.

Power-On Self-Test, step 2Step 2: The CPU

starts the ROM BIOS boot program.

CPU

BIOS

Power-On Self-Test, step 2AStep 2A: The

BIOS boot program starts other checks:A. CPU memory

CPU

BIOS

Power-On Self-Test, step 3Step 3: The CPU

checks the connections to the other devices.

CPU

To keyboard To mouseTo serial ports

To parallel ports

?? ? ?

Power-On Self-Test, step 4Step 4: The CPU

checks the system timer (synchronizer).

CPU

Power-On Self-Test, step 5Step 5: The

POST checks the video card, and integrates the video card’s BIOS with the overall BIOS.

VIDEO CARD

Power-On Self-Test, step 6Step 6: The

RAM is tested.

Power-On Self-Test, step 7Step 7: The

keyboard is checked for any pressed keys.

Power-On Self-Test, step 8Step 8: The CPU

checks to see which disk drives are available.

Power-On Self-Test, step 9Step 9: The

POST results are compared with reference data on the CMOS chip.

Power-On Self-Test, step 10Step 10: Other

devices’ BIOS are integrated with the overall BIOS.

Power-On Self-Test, finished.Now, we can

finally go onto loading an operating system.

Gee, Mrs. Brady, that wasn’t so bad!