Everything you need to know about System BIOS.

Hello folks, This is going to be the first ever post on All Tech Times. So, the first post is going to be about the most important component of computer, that is, BIOS(the initiator of all the programs). So, here we go :-

What Is A BIOS?

BIOS is a technical jargon which stands for Basic input/output system and the synonym terms are system BIOS, ROM BIOS or PC BIOS. It is a type of software firmware inbuilt in the systems and is the first software which runs when the system is powered on. to be very precise, BIOS is a set of built-in-software routine that initiates and test the system components, and is responsible for the loading of operating system from the mass memory.
Earlier, BIOS systems were stored in ROM chip in the mother board but it avoids the mobility of the BIOS and restricts any kind of changes. In order to overcome these shortcomings, now-a-days BIOS Systems are stored in flash memory.

History Of BIOS.

The term BIOS was first tossed by Gary Kildall (Computer Scientist and microcomputer entrepreneur) and first appeared in CP/M (Control Program For Microcomputers ) operating system in 1975.

Functionality Components Of A BIOS.

POST- The POST (POWER-ON-SELF-TEST) checks, identifies and initiates the essential components such as CPU, RAM and other components like input/output devices, display video cards, chipsets etc.
When the system startup takes place by cold boot(pressing the power button or reset button), then the full power-on-self-test(POST) begins and if the startup takes place by warm boot(CONTROL+ALT+DELETE) then a flag value is passed to the non-volatile BIOS memory(a small memory on motherboards to store BIOS settings) before the processor is reset, and after the resetting of the processor the BIOS detects the code and avoids POST. this saves time.
BOOTSTRAP LOADER- It’s Basic function is to locate for an Operating System. If an efficient operating system is found, it passes control to the further processes.
BIOS DRIVERS- Drivers that gives the basic operational control over the computer hardware.
BIOS OR CMOS SETUP- People often confuse that BIOS and CMOS are the same things, but in reality, they are not. CMOS(Complementary Metal Oxide Semiconductor), is basically a RAM chip. It is a memory chip that stores information about the systems components and also stores the settings for those components. like all the RAM’s, it looses the data when the supply of power is turned off and is termed as DEAD CMOS. to overcome the concept of loss of data, a continuous supply of power is given to the CMOS chip by another component in the mother-board named as CMOS battery.
The BIOS chip reads the information from the CMOS chip during the boot up process.
Basically these are the configuration programs which allows the user to configure system and hardware settings such as date, time, calender, computer passwords etc.

BIOS Operation.

To activate a routine, the IBM BIOS issues an appropriate hexadecimal code and the list follows:-
Code in Hexadecimal | Function
00 Divide by zero
01 Single step
02 NMI
03 Break point
04 Over flow
05 Print screen
06 Reserved
07 Reserved
08 System Timer
09 Key Board
0A Reserved
0B Reserved
0C Reserved
0D Reserved
0E Floppy Disk
0F Reserved
10 Video
11 Equipment determination
12 Memory size determination
13 Floppy Disk
14 Asynchronous Communication
15 System services
16 Keyboard
17 Printer
19 Boot Strap Loader
1A System Timer & real Time clock services
1B Keyboard Break
1C User Timer Tick
1D Video Parameters
1E Floppy Disk Parameters
1F Video Graphic Characters
20 – 3F Reserved for DOS
40 Floppy Disk BIOS revector
41 Hard Disk Parameters
42 Reserved
43 Reserved
44 Reserved
45 Reserved
46 Hard Disk Parameters
47 Reserved
48 Reserved
49 Reserved
4A User Alarm
4B – 5F Reserved
60 – 67 Reserved for user program interrupts
68 – 6F Reserved
70 Real Time clock interrupt
71 – 74 Reserved
75 Redirect to NMI
76 – 7F Reserved
80 – 85 Reserved for BASIC
86 – F0 Used by BASIC interpreter while
Running BASIC
F1 – FF Reserved for User program interrupts.

What next in the BIOS generation?

The answer is UEFI (Unified Extensible Firmware Interface). The UEFI can access all the memory installed in the system. UEFI can support remote diagnostics and repair of computers, even without another operating system.

How to enter the BIOS ?

Method 1- Entering your BIOS other than UEFI. (Tested on Windows 7)

1- Restart your System.
2- you will be prompt to press some desire key to enter setup or BIOS. the most common keys are f1,f2,f12.(the keys may vary from system to system). For me it was f12.
Note:- If you don’t hit the key in time, windows will load and you will have it restart it and have to repeat the 2nd step again.
3- you can now navigate through the BIOS using the navigation keys on your keyboard i.e the arrow keys. Most probably, your mouse won’t work.

Method 2- Entering UEFI BIOS in windows 8/8.1.

1-Press the Windows key + C, or swipe in from the right edge of the screen to open your Charms.
2-Click Settings.
3-Click Change PC Settings.
4-In PC Settings, select General.
5-Under Advanced startup, click Restart now. The system will restart and show the Windows 8 boot menu.
6-In the boot menu, select Troubleshoot.
7-In the Troubleshoot menu, select Advanced options.
8-In the Advanced options menu, select UEFI Firmware Settings.
8-Click Restart to restart the system and enter UEFI (BIOS).
Note:- The Windows 8 boot menu will also show automatically after Windows 8 fails to start successfully three times.
For Windows 8.1
1-Press the Windows key + C, or swipe in from the right edge of the screen to open your Charms.
2-Click Settings.
3-Click Change PC Settings.
4-Click Update and recovery, then select Recovery.
5-To the right beneath Advanced Startup, click Restart now.
6-Once the boot menu appears, select Troubleshoot.
7-In the Troubleshoot menu, select Advanced options.
8-In the Advanced options menu, click UEFI Firmware Settings.
9-Click Restart. The system will restart and enter UEFI (BIOS).

Final words.

BIOS will be an eternal part of our systems that seems of not to be retiring in the near future. So, for a technology enthusiast, it becomes a must to have a knowledge of the BIOS and it’s components. Thank you for reading and make sure to share and leave a comment, if you find this post worth reading. 🙂
Sources and citations :-
1- http://acer.custhelp.com/app/answers/detail/a_id/27103/~/accessing-the-uefi-(bios)-setup-on-a-windows-8-%2F-8.1-system
2- en.wikipedia.org/wiki/BIOS
3- en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface
4- http://www.pcpro.co.uk/features/381565/uefi-bios-explained

5- http://www.computerhope.com/jargon/b/bios.htm

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