Can the computer start up when there are no BIOS? Explain?

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  • 2 months ago

    If it is then it is not a computer

  • 2 months ago

    NO, without BIOS computer does not run. Bios is verify your device using POST(Power on self test) method. Also for install any OS on your system you must change it first boot device option which is programmed on BIOS. BIOS is Basic Input Output System.

  • 2 months ago

    The last time a computer was able to start up without a BIOS was when they still had front-panel switches that you could toggle in instructions. 

    What is normally needed is that you have a little snippet of code at disk address <0,0,0> (That's cylinder, track, sector, and it happens that the 0,0,0 address is also the BOOT sector.). 

    Do a hard reset so that the computer registers are also 0.  Manually toggle in a command to the disk control register to read one block from <0,0,0> to memory addresses starting at 0.  Now toggle in a JUMP to address 0.  That little snippet that you load in is called the "vestigial boot loader" or some  similar name depending on manufacturer.  That snippet reads in the next several blocks of the full boot loader, which then reads in more stuff as needed until you have the entire O/S loaded up.

    However, with the advent of relatively cheap EPROMs it became possible to trigger a snippet of code in the EPROM to do the same thing for you without switches.  So now when you trigger a hard boot, you trigger a jump to an address in the EPROM that takes care of the rest.

    Technically, that still isn't a BIOS.  That came about when it became desirable to allow alternative boot devices and a few other functions.  If the BIOS is broken, you no longer have a way to load instructions to memory and without those instructions, you cannot start the computer.  That is because you can't trigger the disk read operation to get the vestigial boot loader into memory.

  • Anonymous
    2 months ago

    The BIOS executes all the startup functions!

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  • 2 months ago

    Not automatically, without a BIOS or equivalent "built in" program that it executes when switched on.

    No BIOS etc. means no way for the computer to load any program or operating system. It's just inert parts without a program.

    The user would have to manually load in a bootloader to start the boot-up sequence, using the machine's operator panel switches.

    (Search "minicomputer operator panel" on google & select images to get an idea what they were like).

    As someone else mentioned, that was normal back in the 50s & 60s, the computer operator had to manually key in the first stage bootloader program, one instruction at a a time, to allow the computer to load its working programs.

    Dedicated or "embedded" systems that have a single fixed program built in, like anything from DVD player to a car engine management units, do not have a BIOS as there is no need for the computer to work out what options and parts it has, or load an operating system to allow someone to add and run their own programs.

    They just directly start and run the dedicated program that is built in to them.

    So technically no BIOS, but still a built-in program.

  • Lv 7
    2 months ago

    sure. but it won't do much without instructions.

    most modern PCs use UEFI instead of BIOS. it allows for mouse use, and a more updated look and feel in the GUI, rather than just using the keyboard.

    remember, regardless of how fast a computer is, a computer will NOT do anything unless it is explicitly told to.

    the Basic Input/Output System (BIOS) and Unified Extensible Firmware Interface (UEFI) tells the computer what to do once it is turned on, and where the OS should be located, and gives the computer basic settings of what it can do with its firmware.

  • Murzy
    Lv 7
    2 months ago

    BIOS = Basic Input output system

  • 2 months ago

    No, the BIOS contains the first instructions a computer runs before reading the operating system.

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