Channel: itfreetraining

Category: Education

Tags: computer biosbiosa+comptia a+itfreetraining

Description: This section of the ITFreeTraining courses will look at the BIOS. BIOS or Basic Input/Output System is the software that is responsible for initially testing and communicating with your hardware. Without the BIOS the computer would not start. This video will look at what the BIOS can do, upgrading the BIOS and how the BIOS works. Download the PDF handout: itfreetraining.com/handouts/ap/1b45.pdf What is BIOS? 0:20 To start with, I will first look at what the BIOS is. Essentially, the BIOS is a microchip found on the motherboard. BIOS is essentially what is referred to as firmware. Firmware contains basic low-level software that controls the hardware in the device it is installed in. In the case of computers, the BIOS contains basic input and output software which is used to communicate with hardware. When the computer is first switched on, the BIOS software is used to test the hardware within and connected to the computer. Once complete, the software in the BIOS is used to access the hardware. BIOS was first created in 1975 by IBM. It was later reverse engineered to be used in non-IBM computers. Nowadays there are three companies that make the majority of BIOS chips and IBM is not one of them. I will now have a closer look at what happens when a computer starts up, to give you a better understanding of how the BIOS works and what it does. Powering Up PC 1:20 To start with, I will first look at what happens when the power button is pressed on a computer. When the power button is pressed, a circuit is closed which causes a test to be preformed of the computer’s power supply. If there is a problem with the power supply, usually there will be no power output at all and the computer will not start. If the power supply test is o.k., the power supply will send power to the CPU. Now the CPU has powered up, it will start executing instructions, because that is what a CPU was designed to do. In order to do this, it needs software and this is where the BIOS comes into play. Load BIOS Software 1:56 The BIOS is essentially a microchip on the motherboard. This is also often referred to as firmware. Older BIOS chips use Electrically Erasable Programming Read-Only memory called EEPROM, whereas modern BIOS uses flash RAM. This allows the code in the BIOS to be updated, but the code on the BIOS cannot be directly run from the chip itself. In order for the CPU to execute the code in the BIOS, the code in the BIOS is copied to the memory inside the computer. So essentially this means that in order for a computer to start, it requires memory. If you attempt to power up a computer that does not have memory installed, the motherboard will emit a number of beeps to alert you that there is a problem. Once the BIOS code has been copied to memory, the CPU can now start executing the code. So essentially what happens is this. When you press the power button, the code in the BIOS is copied to memory and then is executed by the CPU. The next question is, what does this code do? POST Tests 2:57 The next step is that the BIOS performs a number of tests. These tests are referred to as POST or power- on self-test. These are a number of quick tests to check everything appears to be working. There may still be hardware faults, but the POST tests should pick up any basic problems. POST tests include but are not limited to, checking the memory installed. This is a quick check to see if everything appears to be working correctly. There are a number of memory testing software tools available that can do more advanced tests if required. Tests also include checks of any attached storage devices. This is basic testing to ensure the devices start up and are accepting commands. For example, a hard disk test would spin the drive up and test it to ensure the drive can be accessed. Other checks include checking the keyboard. The check tests every key on the keyboard. Depending on the BIOS, if a stuck key is detected a warning message will appear. Any devices like a mouse are also checked. This includes devices like trackpads and trackballs. Description to long for YouTube. Please see the following link for the rest of the description itfreetraining.com/ap/1b45 References “BIOS” en.wikipedia.org/wiki/BIOS “The Boot Process” opsschool.org/en/latest/boot_process_101.html Credits Trainer: Austin Mason ITFreeTraining.com Voice Talent: HP Lewis hplewis.com Quality Assurance: Brett Batson pbb-proofreading.uk