Today, I started talking about some of the knowledge of BIOS. From the most basic beginning, I didn't have a complete absorption, completely mastered. Below you still start today's review. Bios (Basic Input Ouput System, Basic Input Output System), this concept should be first. Its basic meanings, first it is a set of procedures that are cured on computer hardware (motherboard), is the bridge between computer hardware and software, providing the lowest, most direct hardware control for the computer, responsible for starting at the computer Detection, initialization system equipment, load an operating system, and schedule an instruction sent to hardware. How can a lot of things can quickly understand it? It is a group of programs, communication hardware and software, and our most direct understanding is the POST (Power On System Test), when the computer is powered on, the BIOS will check all the devices inside, including the CPU, memory, only Read memory, system motherboard, CMOS memory, parallel, and serial communication subsystems, floppy disks and hard drives, and keyboards. After the self-test is over, the system will look for an operating system in the specified drive and load the operating system to the memory. What are the basic features of BIOS? Including the BIOS interrupt service program, the BIOS system setup program, POST, BIOS system launching the bootstrap program, etc. What are the classification of BIOS? When this place, relatively, it was a bit fine, not written in the book, just classified according to the brand. Here, there are six categories here. Let's introduce one by one. 1. Classified according to the carrier (BIOS chip), mainly experienced five stages. The first is the ROM (Read Only Memory) Read-only memory, which is the first generation of BIOS, then the PrOMMable ROM programmable memory, followed by eProm (Erase Programmable ROM) Obsolete Card programming memory, In this generation, BIOS should say that development is already, but the number of erasing times, there is an EEPROM (Electrical Erasable Programmable ROM)
The erasable programmable memory is also called E-square ROM. With the development of technology, Flash ROM has started to be applied by the majority of vendors, so many of the market is now Flash Rom. 2. Classified according to the capacity of the BIOS chip. In the 486 era, the 512K BIOS ROM, after Pentium, start to switch to 1M ROM, after P4, more and more 2 ---- 4m 3. Follow the BIOS brand classification, three main types Brand BIOS. AMI, AWARD, PHOENIX, AMI BIOS application in the early model of 486, which is characterized by a variety of soft and hardware adaptability. Award BIOS is currently widely used, which feature full function and supports many new hardware. Phoenix is primarily applied to laptops, and now Phoenix has merged with Award. Many motherboards will appear Phoenix - Award BIOS, so I see this type of BIOS should not be odd. 4. Classify, DIP and PLCC according to the chip package, I still can't explain what is the meaning of the bottom, I can only explain intuitively, one is a double-column insertion, one is around the solder foot Chip, where it is to note when DIP is identified, it is welded throughout the motherboard or board. 5. Follow the manufacturer of ROM chips, WinBond (Taiwan Huabang), Intel, Atmel, SST, MXIC, etc. Wait for a common BIOS chip model, if you see it should be recognized, you can identify the BIOS production company, its capacity. Here, just the memory method, the previous letters often represent the company, such as AM, representing AMD, capacity, this place, I have a clear understanding of myself, for example, atmel29c020, this represents Atmel produces 2M capacity BIOS chip. After finishing the BIOS, start thinking about a problem, since it is a program, where does it save? I have to talk about CMOS when I think this question. CMOS (Complementary Metal-Oxide Semiconductor) mutual metal oxide semiconductor, characterized by fast speed, extremely low power consumption, good anti-interference performance, function: Save the parameter data set by the BIOS. Capacity: 128Byte or 256Byte, information maintenance: dry battery or rechargeable lithium battery. There is such a sentence to compare the relationship between BIOS and CMOS: BIOS is a means of completing parameter settings. It is a program that CMOS is a storage place for system parameters. It is a readable and writable RAM chip. OK, talking about it, it is also a relatively initial understanding of the BIOS. At least at someone talked about the BIOS setting, talking about CMOS will not be full of mist, I don't know how to get it. Let's write here first.
