The Simple Computer
The Simple Computer
POST
Power on self-test (POST) is a test which the computer completes on start-up which will verify whether the hardware is all working correctly. If the hardware is working correctly the computer will continue to boot if not a beep code is generated. A BIOS may have a different beep code depending on what type of BIOS it is.
Steps of POST (Power on self-test)
Power on self-test (POST) is a test which the computer completes on start-up which will verify whether the hardware is all working correctly. If the hardware is working correctly the computer will continue to boot if not a beep code is generated. A BIOS may have a different beep code depending on what type of BIOS it is.
Initial hardware checks for instance identifying the amount of memory present
Identification of the devices which are needed to start the OS such as the hard disk, RAM, CPU.
System configuration settings are retrieved from non-volatile memory on the motherboard
While there are several different types of beep codes the two most common are AMI and Phoenix. I have acquired the beep codes and their descriptions and represented them in the tables below.
Beep codes for AMI
Beep Codes
Descriptions
1 short
DRAM refresh failure
2 short
Parity circuit failure
3 short
Base 64K RAM failure
4 short
System timer failure
5 short
Process failure
6 short
Keyboard controller Gate A20 error
7 short
Virtual mode exception error
8 short
Display memory Read/Write test failure
9 short
ROM BIOS checksum failure
10 short
CMOS shutdown Read/Write error
11 short
Cache Memory error
1 long, 3 short
Conventional/Extended memory failure
1 long, 8 short
Display/Retrace test failed two-tone siren
Low CPU Fan speed, Voltage Level issue
Beep Codes for Phoenix
Beep Code
Description
1-1-1-1
Unconfirmed beep code... reseat RAM chips or replace RAM chips as possible solution
1-1-1-3
Verify Real Mode.
1-1-2-1
Get CPU Type.
1-1-2-3
Initialize
POST
Power on self-test (POST) is a test which the computer completes on start-up which will verify whether the hardware is all working correctly. If the hardware is working correctly the computer will continue to boot if not a beep code is generated. A BIOS may have a different beep code depending on what type of BIOS it is.
Steps of POST (Power on self-test)
Power on self-test (POST) is a test which the computer completes on start-up which will verify whether the hardware is all working correctly. If the hardware is working correctly the computer will continue to boot if not a beep code is generated. A BIOS may have a different beep code depending on what type of BIOS it is.
Initial hardware checks for instance identifying the amount of memory present
Identification of the devices which are needed to start the OS such as the hard disk, RAM, CPU.
System configuration settings are retrieved from non-volatile memory on the motherboard
While there are several different types of beep codes the two most common are AMI and Phoenix. I have acquired the beep codes and their descriptions and represented them in the tables below.
Beep codes for AMI
Beep Codes
Descriptions
1 short
DRAM refresh failure
2 short
Parity circuit failure
3 short
Base 64K RAM failure
4 short
System timer failure
5 short
Process failure
6 short
Keyboard controller Gate A20 error
7 short
Virtual mode exception error
8 short
Display memory Read/Write test failure
9 short
ROM BIOS checksum failure
10 short
CMOS shutdown Read/Write error
11 short
Cache Memory error
1 long, 3 short
Conventional/Extended memory failure
1 long, 8 short
Display/Retrace test failed two-tone siren
Low CPU Fan speed, Voltage Level issue
Beep Codes for Phoenix
Beep Code
Description
1-1-1-1
Unconfirmed beep code... reseat RAM chips or replace RAM chips as possible solution
1-1-1-3
Verify Real Mode.
1-1-2-1
Get CPU Type.
1-1-2-3
Initialize
Bibliography: Computer Post and Beep Codes . (n.d.). Retrieved from Computer Hope: http://www.computerhope.com/beep.htm POST. (n.d.). Retrieved from Computer Hope: http://www.computerhope.com/jargon/p/post.htm Power-on self test Phase . (n.d.). Retrieved from http://sourcedaddy.com/windows-7/power-on-self-test-phase.html. ramly, h. (n.d.). Computer Input Device . Retrieved from tecHnOholiC: http://hoyevernever.blogspot.co.uk/2013/01/simple-input-device.html