1. The Basic Input/Output System Unit objectives: Access the BIOS setup utility, change hardware configuration values, and research BIOS updates Explain the POST and boot processes; and identify the symptoms of, probable causes of, and potential solutions to problems with the BIOS and POST

2. Topic A Topic A: The BIOS and CMOS Topic B: The POST and boot processes

3. Firmware Gray area between hardware and software Software written permanently or semi- permanently to a computer chip Used to control electronic devices Implemented in PC with BIOS and CMOS

4. BIOS Basic Input/Output System A set of software instructions stored on a chip on the motherboard Enables basic computer functions Common BIOS manufacturers: –AMI –AWARD –MR BIOS –PHOENIX Many use shadowing

5. CMOS Area of memory that stores BIOS configuration information Battery provides power to CMOS Type of computer chip: complementary metal oxide semiconductor Can maintain information without a supply of power

6. CMOS battery

7. CMOS configuration Configure with system setup utility –Built in BIOS –Locate on separate hard disk partition –Stored on disc Access to utility varies by manufacturer List of CMOS access keys: –http://murfsgarage.cybertechhelp.com/  cmossetup.htm

8. CMOS configurable settings Date and time CPU options Optical drive options Floppy drive options Hard drive options Serial port options Parallel port options Integrated devices Plug and Play continued

9. CMOS settings, continued Power management options Virus detection Boot password

10. Activity A-1 Updating your PC’s BIOS settings

11. BIOS updates BIOS implemented either in: –ROM: Programmed at factory –Flash memory: Can update, “flash,” the BIOS Update if you: –Have device problems or other bugs that PC manufacturer says are caused by BIOS problems –Have device problems that can’t be attributed to anything else; have exhausted all other troubleshooting avenues –Need to use new hardware options that are supported by motherboard but not by BIOS

12. BIOS update sources Links to BIOS updates and flashing utilities on PC manufacturer’s Web site BIOS is tailored by each PC manufacturer Don’t go to BIOS manufacturer’s Web site

13. Determining the BIOS version 1.Open System Information 2.Record BIOS Version/Date field value 3.If present, record SMBIOS field value

14. Flashing the BIOS 1.Determine current BIOS version 2.Go to PC manufacturer’s Web support pages 3.Compare available updates with current version 4.Download new BIOS version 5.Download flashing utility 6.Close all open windows 7.Open flashing utility; follow instructions 8.Restart PC

15. BIOS update guidelines Don’t update your BIOS unless you must Never turn off your computer during a BIOS update –Connect to a UPS Use the correct BIOS flash utility Follow instructions exactly Back up BIOS if possible

16. Recovering from a failed update Use BIOS backup to restore previous version Use “boot block” Use flash recovery jumper switch Obtain new BIOS chip

17. Activity A-2 Researching BIOS updates for your PC

18. Bad CMOS battery BIOS data retained due to CMOS battery Older PCs had a soldered battery— not replaceable Newer PCs have removable battery

19. Low battery errors Loss of time or date at boot CMOS Read Error CMOS checksum error CMOS Battery Failure

20. Replacing the CMOS battery 1.Record custom CMOS setting values 2.Power down; open your computer’s chassis 3.If necessary, remove cables to allow battery access 4.Gently slide the battery out of its compartment 5.If necessary, discharge the CMOS memory using motherboard jumpers 6.Insert the new battery into the holder 7.Reconnect any cables you disconnected to gain access to the battery 8.Close the PCs chassis 9.Reconnect any cables and power cord 10.Reboot. Enter correct date and time 11.Access BIOS to reset custom values

21. Activity A-3 Replacing the CMOS battery

22. Topic B Topic A: The BIOS and CMOS Topic B: The POST and boot processes

23. POST process Power-on self test 1.BIOS tests core hardware 2.BIOS tests video subsystem 3.BIOS identifies itself, including its: Version Manufacturer Date 4.BIOS tests main system memory

24. Beep codes Inform user of errors before display is loaded Vary by manufacturer www.computerhope.com/beep.htm Common beep codes: –1 short beep = No problems found –3 long beeps = Keyboard error –8 short beeps = Video adapter memory problems –9 short beeps = BIOS problem –1 long + 3 short beeps = Memory error

25. Numeric codes Informs user of errors after display is loaded Vary by manufacturer IBM numeric code examples: –151 = Real time clock failure –161 = Bad CMOS battery –162 = Configuration mismatch –164 = Memory size mismatch –201 or any 20# = Memory failure –1762 = Hard drive configuration error

26. Activity B-1 Observing the POST process

27. The boot process 1.You turn on the power 2.Timer chip sends reset signals to CPU to prevent booting 3.Power supply performs internal checks; sends Power_Good signal to CPU 4.Timer stops sending reset signals to CPU 5.CPU loads BIOS and BIOS extensions 6.BIOS checks whether this is a cold or warm boot continued

28. The boot process, continued 7.If cold boot, BIOS performs POST 8.BIOS reads CMOS and configures devices 9.Plug and Play devices detected and configured 10.BIOS determines which drive to boot from 11.BIOS reads the master boot record from drive 12.OS takes over and completes the boot process

29. Boot devices Used to load operating system Current: –Internal hard disk –Optical drive: CD or DVD –USB drive: flash drive or external hard disk or optical drive –Network drive, using a PXE network interface card Older: –Floppy disk drive –SCSI device –Zip drive

30. Boot devices in the system BIOS

31. Activity B-2 Checking the boot order

32. BIOS-related problems Devices misidentified Wrong memory size reported during POST or available during booting Hard drive inaccessible System won’t boot from hard drive System boots from the wrong device Date and time incorrect or reset after computer is turned off

33. POST-related problems There’s no video; instead, the computer sounds 8 short beeps The system emits 3 long beeps The system emits 1 long and 3 short beeps POST code 162 is displayed POST code 164 is displayed

34. CMOS-related problems Error messages: Non-system disk or disk error Display type mismatch Memory size mismatch CMOS checksum failure

35. Activity B-3 Troubleshooting BIOS and POST problems

36. Unit summary Accessed the BIOS setup utility, changed hardware configuration values, and researched BIOS updates Explained the POST and boot processes; and identified the symptoms of, probable causes of, and potential solutions to problems with the BIOS and POST