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Editor to share with you what the bois system means, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

The full name of the bois system is "Basic Input Output System", which means "basic input and output system" in Chinese; it is actually a group of programs solidified on a ROM chip on the motherboard in the computer, which stores the computer's most important basic input and output programs, post-boot self-test programs and system self-starting programs.

BIOS is an acronym for "Basic Input Output System". After literal translation, the Chinese name is "basic input and output system". On IBM PC compatible systems, it is an industry standard firmware interface. The word BIOS first appeared in the CP/M operating system in 1975. BIOS is the first software loaded when a personal computer starts up.

In fact, it is a group of programs solidified on a ROM chip on the motherboard in the computer. It stores the computer's most important basic input and output programs, post-boot self-test programs and system self-start programs. It can read and write specific information of system settings from CMOS. Its main function is to provide the lowest and most direct hardware setting and control for the computer. In addition, BIOS provides some system parameters to the operating system. The changes in the system hardware are hidden by BIOS, and the program uses the BIOS function instead of directly controlling the hardware. Modern operating systems ignore the abstraction layer provided by BIOS and directly control the hardware components.

Nowadays, this system has become the target of some virus Trojans. Once this system is destroyed, the consequences will be unimaginable.

Main chip

The BIOS setup program is stored in the BIOS chip, and the BIOS chip is a rectangular or square chip on the motherboard, which can be set only when it is turned on. (generally, when the computer starts up, press F2 or Delete to enter the BIOS to set up, and some special models press F1, Esc, F12, etc.) The BIOS setup program mainly manages and sets the basic input and output system of the computer to make the system run in the best state. The BIOS setup program can also be used to troubleshoot or diagnose system problems. Some people think that since BIOS is a "program", it should belong to software and feel like a commonly used Word or Excel. However, many people do not think so, because it is still different from ordinary software, and it is also quite closely related to hardware. Figuratively speaking, BIOS should be a "bridge" between software programs and hardware devices, responsible for solving the immediate requirements of hardware. The BIOS chip on the motherboard may be the only chip with a label on the motherboard. It is usually a 32-pin dual in-line integrated circuit with the word "BIOS" printed on it.

ROM

In the early days of the development of microcomputer (microcomputer Microcomputer System), BIOS was stored in ROM (Read Only Memory). The internal data of ROM is recorded in a special way in the factory during the manufacturing process of ROM, and the contents can only be read and not changed. Once burned, the user can only verify whether the written data is correct and cannot make any further changes. If you find any errors in the data, you have no choice but to abandon them.

EPROM

EPROM (Erasable Programmable ROM, erasable programmable ROM) chip can be erased and written repeatedly, which solves the disadvantage that ROM chip can only write once. EPROM chip has a very obvious feature, in its front of the ceramic package, there is a glass window, through which you can see its internal integrated circuit, ultraviolet light through the hole to illuminate the internal chip can erase its data, to complete the chip erase operation to use EPROM eraser. A special programmer is used to write data in EPROM, and a certain programming voltage must be added when writing to the chip (VPP=12-24V, depending on different chip models). The EPROM model starts with 27, for example, the 27C020 (8mm 256K) is a 2m Bits capacity EPROM chip. After writing the data, the EPROM chip also seals the window with opaque stickers or adhesive tape to avoid damage to the data caused by the surrounding ultraviolet radiation.

EEPROM

Due to the inconvenience of EPROM operation, most of the BIOS ROM chips on the motherboard after 586 use EEPROM (Electrically Erasable Programmable ROM, electrically erasable programmable ROM). Through the jumper switch and the driver disk equipped with the system, EEPROM can be rewritten and BIOS can be upgraded conveniently.

BIOS chips are mainly stored in:

● self-diagnostics: identify, self-test and initialize the hardware configuration by reading the contents of the CMOSRAM

● CMOS setup program: during the boot process, start with a special hotkey, set it up, and store it in CMOS RAM

● system bootstrap loader: after a successful self-test, load the bootstrap program on the disk relative to track 0 into memory and let it run to load the DOS system

The main driver and interrupt service of ● device: because BIOS deals with system hardware resources directly, so it always aims at a certain type of hardware system, and all kinds of hardware systems are different, so there are different kinds of BIOS. With the development of hardware technology, different versions of the same BIOS have appeared successively. The new version of BIOS is more powerful than the old version.

NORFlash

Since the Pentium era, modern computer motherboards have used NORFlash as the memory chip of BIOS. In addition to having a larger capacity than EEPROM, the main reason is that NORFlash has the write function, and the running computer updates BIOS by way of software without additional hardware support (usually EEPROM erase and write requires different voltages and conditions), and the writing speed is fast.

The above is all the contents of this article "what does the bois system mean?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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