Main notions and operation BIOS

Main notions and operation BIOS

Introduction

Word BIOS - an abbreviation on English base system entering/conclusion: Basic Input Output System. This system presents itself set of the small programs, in functions which enter initial testing and ensuring the interaction computer system component between itself, as well as with operating system and applied program. Essentially, BIOS is certain intermediate layer (the interface) between programme and hardware parts of the computer system.

Their own BIOS have a different controllers, video board, spindles, modems, scanners and others, internal and peripherals of the computer. This so named BIOS adapter, which are loaded when start the system. However the most important in computer is BIOS, located on maternal board and named system BIOS. In system BIOS are found all main system software of the computer, intended for testing at power-up of the hardware and control them, as well as for sharing resource between component of the computer.

When functioning(working) the computer operating system addresses directly to hardware provision through BIOS. Such address turns out to be possible therefore that in system BIOS is kept not only program for testing, but also others, intended for activation and control hardware provision in operation computer. Such program are identified the driver a device. Herewith in each operating system - DOS, Windows 9x/NT/2000, OS/2, Linux or other - for one and same device necessary their own, wholly certain drivers. Since program-drivers much are often caused by operating system and applied program, they are constantly kept in BIOS, rather then are started every time when enabling one and same device.

In system BIOS contains the drivers main component required for initial start the computer. That concerns such device, as video devices, drives CD-ROM, hard disks with interface SCSI, sound adapters, scanners, printers and others then when start the computer in them person of need no. So procedures to their initialization in system BIOS are absent - a necessary drivers are loaded with hard disk during start the operating system.

Thereby, program system BIOS are executed when start the computer before boot the operating system. In most cases, PC-compatible computer system BIOS contains the following main programs:

" Program POST - самотестирование processor, modules to operative memory, set of the microcircuits, spindle, keyboards and other vitally important component of the computer system when cut-in of her(its) power supply.

" Program CMOS Setup Utility - конфигурирование computer system and adjustment her(its) parameter. This program is started after striking the certain key during performing the procedure POST. In old computer on the base processor 286 and 386 for start of this program necessary to have a special diskette.

" Initial loader of the system - an execution of searching for main load sector on disc device. The Programme code of this loader is executed if the last two bytes of this sector (the label) turn out to be equal 55ААh.

" Drivers BIOS - a set driver, intended for interaction of the operating system and hardware when start the computer. When start DOS or Windows (in mode of protection from malfunctions) are used drivers device from system BIOS only.

However some device when start the computer, be, all, necessary. For instance, for image of information on screen of the monitor when boot the computer is required actuate видеоадаптер, but his(its) support in system BIOS not built-in. This is because at present there is ensemble different видеоадаптеров, and all their drivers impossible to place in system BIOS. So necessary drivers fit in microcircuits BIOS on board these device. System BIOS when boot the computer realizes searching for BIOS видеоадаптера and loads her(it) before start the operating system. This prevents need to constant modernization system BIOS at appearance of the new models device, particularly that, which required for bootstrap of the computer.

Own BIOS often are fixed and on some other plug-in card. Is it Below brought list of the boards, on which, as a rule, are fixed own BIOS, and is given their thumbnail sketch:

" Videoadaptery - they are always supplied by own microcircuit BIOS.

" SCSI-adapters - these BIOS support not all SCSI-device: for drives CD-ROM, scanner, ZIP- and the other device with interface SCSI additional drivers necessary to load with disk.

" Network adapters - are intended for initial initialization device or normal operation in diskless workstation and terminal.

" Board of the renovation IDE or spindle - are intended for support of the functions load device when start the computer system.

" Board for decision of the problem Y2K - were actual at the end past centuries for decision of the problem 2000; in they are kept the correct program of the transition at new millennium.

Functioning(working) the user in disc operating system MS-DOS is realized by way of the direct address to subroutine BIOS. The more making operating systems such as Windows 9x/2000/Me/NT, have an own facilities for governing hardware component computer so under its functioning they it is enough seldom use system BIOS.

Main information about system BIOS computer

Physically system BIOS presents itself microcircuit (or set of the microcircuits) to constant memory ROM, or ROM, located on maternal board. So such microcircuit often name ROM BIOS, but program system BIOS itself - BIOS maternal board. ROM BIOS - got up in panel of the maternal board microcircuit with 28 or 32 contacts; she is provided with holo by sticker and inscription-logotype of the producer given BIOS. Often, the microcircuits впаиваются in system board straight. The Microcircuits ROM BIOS can have a different volume, but more often he forms 128 or 256 Kb.

As a rule, near by microcircuit ROM BIOS is found nickel-cadmium battery or lithium element (the battery), supplying microcircuit CMOS and constantly подзаряжаемый in operation computer. Such are a supplying elements are fixed for the reason conservations of information in microcircuit ROM after de-energization. So microcircuit ROM often name nonvolatile, but this not quite faithfully. The Microcircuits ROM, all, need for autonomous power supply so memory of such microcircuits to should name the memory with autonomous feeding.

Shadowing ROM-memories

The Microcircuits BIOS very slow: time of the access forms 150 ns under that that time of the access rememberring device DRAM forms 60 ns or less. So in many system ROM-memory separate component "is shaded" i.e. when start the computer her(its) contents is copied in microcircuit of the dynamic operative memory so as in process of the operation to shorten time of the access to hereto contents. The Procedure of the shadowing copies contents ROM in operative memory, assigning her address, originally used for ROM memories, which then is practically disconnected. In most cases it turns out to be sufficient to shade only base system of the entering/output on maternal board and, possible, on видеоадаптере. However modern BIOS give the broad possibilities for shadowing ROM-memories many other component computer in program CMOS Setup Utility.

Shadowing effectively, mainly, in 16-bit operating system DOS or Windows 3.x. But if computer runs under 32-bit operating system of the type Windows 9x or Windows NT/2000/Me, that shadowing practically turns out to be useless, since these operating systems do not use 16-bit code from ROM-memories. Instead of it they load 32-bit drivers in operative memory, changing them 16-bit code of the base system of the entering/output, which, thereby, is used only during start the computer system.

Functioning system BIOS when enabling the computer

The First that occurs when striking the button Power on body of the computer, - самотестирование his (its) power supply unit. Are they Herewith checked voltages of the feeding separate line, and if they in accuracy correspond to the requirement of the computer system, is worked out signal Power Good (the voltage in rate). This occurs approximately through 0,1 0,5 with after enabling the computer, depending on type and quality power supply unit. Only after this on special entering the central processor simultaneously with feeding is flashed a signal Reset (the unset).On this signal processor zeroizes contents of the higher part to operative memory, goes to the address FE000h system (constant) to memories and begins performing the programs BIOS.

Hereinafter process of the initial boot the computer has such sequence:

1. Cut-in in functioning(working) the central processor

2. Start the programs system BIOS

3. Searching for and initialization BIOS adapter device

4. Testing to operative memory

5. Enabling the keyboard

6. Testing port and connected device to him

7. Initialization spindle and hard disk

8. Distribution resource between initialized device Results diagnosticses and initializing the hardware as total system information are displayed on screen of the monitor in the manner of tables. Following data is specified In this table:

" volume to operative memory;

" connected IDE-device and modes of their functioning;

" included ports and used by them facility;

" information about device, connected to bus PCI.

After termination POST-test and initialization computer component system BIOS defines, on what spindle are found load files of the operating system. The command generates After finding of these files BIOS on their boot in operative memory.

Program CMOS Setup Utility adjustment BIOS

In the course of adjusting the hardware of the computer system in the first place tune in the interfaces of the maternal board. After achievement reliability and clearness of the interaction all device and component possible to try to obtain optimum computer power, saving in ditto time reliability his(its) functioning. For this there is special built-in program in microcircuit ROM BIOS, which enables the user to install importances different parameter computer system - a conditions and state of working internal component and peripheral equipment. Is identified this program CMOS Setup Utility that in literal translation with english means "Utility of the installation (adjustment) CMOS-memories". Often in literature, both in domestic, and in foreign, this program often name simply BIOS Setup.

Contents of the main sections of the program BIOS Setup

The program menu Main of the installation BIOS different producers and version has, as a rule, united structure. Now and then in program CMOS Setup Utility miscellaneous version contribute rather significant change, sense which in that that are added new main sections and options, allowing make the most possibility of the new maternal boards, and delete old, exhausted its need.

We shall Consider the main sections most new program of the installation Phoenix-Award BIOS CMOS Setup Utility.

Standard CMOS Features

This - a section so named standard adjusting the computer, which contains the most archaic parameters, appeared else 20 years back, when CMOS Setup Utility presented itself separate program, not falling into system BIOS. The Options of this section allow to assign base system information for some hardware (such as hard disks, different spindles), as well as install the system date and time. They Here are found information fields, in which is specified amount installed in computer of the memories.

Usually change the parameters of this section is not required: standard installation at all do not influence upon computer power, but only define his(its) deskside. The Exception form that events, when run down the supplying element of the microcircuit CMOS-memories or occurs some other malfunction, led to loss of information, or you have changed the deskside of your computer system. Then, certainly, come anew to install all necessary конфигурационные importances parameter this section.

Much it is important to support the correspondence to between introduced here parameter of the hardware of the computer and real feature connected device. If, for instance, in this window will is untrue specified type of the hard disk, that start the computer will become the impossible.

Advanced BIOS Features

This section contains the set additional parameter general-purpose, not connected with specific computer configuration. In him concentrated big amount of the preliminary installation required for efficient functioning(working) the computer. The Parameters given section allow to define the state of working computer system such as process of the initial testing, order of the boot the system (i.e. order of the questioning device on presence load record), state of working keyboards and memories, functioning cache-memories and a great deal another. Some options enable to accelerate start the computer or raise reliability of his(its) functioning.

Advanced Chipset Features

This section plays the key role in optimization of the functioning(working) the computer. The Options given section allow to adjust functioning to operative memory, chip maternal board and other device of the computer. The Majority of importances of the section install the velocity of the functioning component to desksides for frequencies of the functioning(working) the maternal board (for processor - an external frequency). Some are modern чипсеты maternal boards allow also to use installed here anisochronous mode, in which frequency of the functioning to memories does not comply with frequency of the central processor.

The Modern modules to operative memory is kept description their own parameter inwardly itself that provides automatic adjusting the mode of the access to him. However this nowhere near does not guarantee that such mode will be optimum. This particularly fair for maternal boards past years of the issue - then and microcircuits SPD were used not around the world, and typical temporary diagrams of the address to memories were other. Adjusting the features to memories particularly essential if its computer you have gained not in ready type, but collected him(it) by itself or by means of friends, or have even entrusted this company-seller. The Purpose of such assembly - form the runnable computer system, but uzh optimization her(its) parameter, as a rule, or is postponed for the future, or in general does not be taken in attention.

Changing importances option this section possible vastly to affect on power not only, but also on stability of the functioning(working) the computer. So wrong installation parameter can bring about that that computer in general will not be started.

Integrated Peripherals

The Givenned section contains the options for adjusting device, integrated with чипсетом maternal board, and in significant measure is reduced to possibility simply to disconnect some device. Such unhooking necessary if given integrated device конфликтует with the other device, marketed in the manner of plug-in card.

In section Integrated Peripherals, besides, possible adjust the parameters an interface IDE, built-in consequent and parallel port, as well as integrated in modern maternal board infrared radiation controller (though port itself most often does not be fixed).

In some version BIOS this section is absent, but connected with him options without fall there are in some other section.

Power Management Setup

In this section purpose all option is connected with function of энергопотребления computer. They allow at a rate of BIOS to control the power supply of the computer and his(its) transition in mode lowered энергопотребления - in so-called "sleeping" mode.

Since operating system Windows itself capable to control the power supply of the computer, that corresponding to options better to disconnect.

PnP/PCI Configurations

This section is used for governing fine adjusting the distribution computer system resource between device, connected to bus PCI - a channels DMA, interruptions, ports of the entering/output. Such device there are in all modern computer, and they, as a rule, correspond to the standard Plug and Play. When functioning(working) such device operating system itself is chosen by him interruptions and channels of the direct access to memories if in this will appear need.

PC Health Status

This section is intended for image of information on condition separate component computer such as central processor and чипсет. Is it Here displayed temperature, voltages of the feeding, velocities of the rotation ventilator, but in that event only if there is built-in mechanism of the monitoring in system corresponding to parameter.

Frequency/Voltage Control

In this section possible to expose non-standard importances of the frequencies of the processor, modules to memories, system bus or graphic accelerator, assign the raised voltages of the feeding on these component of the computer.

Adjustment computer system parameter

Installing the date and time

There is device In each computer, which directly does not affect neither on power, nor on stability of the functioning(working) the computer, but without which can not orderly function neither operating system, nor applied programs. This - rtc.

Hard disks

IDE HDD Auto Detection

The Automatic determination and image on screen of the monitor parameter hard disk.

IDE Primary Master/Slave and IDE Secondary Master/Slave

Here is fixed information on type spindle, which must be included in documentation from supplier your hard disk. If you choose Auto, BIOS automatically defines the parameters given spindle in step of POST and shows IDE for it. If spindle is not installed, choose None.

Capacity, SIZE

Here is fixed the capacity used hard disk. The Capacity of the disk possible to compute, multiplied consecutively number cylinder on number of the heads, on number sector and on 512 bytes.

Halt On, Error Halt, POST Error Halt, POST Errors

The Option Halt On by default has importance All Errors. This means that when start and самотестировании when finding the error boot will be discontinued. The Stop of the boot is because of some error possible to canceal by means of this options.

Process of the boot

Boot Up System Speed

The Option of the choice of the clockrate of the processor when boot. Importance "Low" translates the processor in state of working with half clockrate and without use internal cache-memories. Naturally that изначально is lowered reception capacity of the system bus. Such mode can be needed when work with old program or plug-in card, as well as under possible problem when start the system. By default always is fixed importance "High".

Boot Virus Detection

The Determination of the virus in load sector. The Sense of this parameter differs from "Virus Warning" and is concluded he in following. If this parameter prohibited ("Disabled") then before boot the operating system BIOS copies the load sector in флэш-memory and saves him(it) there. But herewith no consequence for system and user does not appear. When installing the parameter in "Enabled" BIOS will not load the system with hard disk if the contents boot-sector will differ from saved in memories. At, the system removes the message, and user, hereinafter, is given possibility or load the system with hard disk, or with diskettes.

Virus Warning

Warning about virus. The Permit of this parameter ("Enabled") forbids any record in load sector of the hard disk or table of the sections (partition table). In an effort change of these areas BIOS stops the system with output on screen of the monitor corresponding to messages, as well as bleep. At user can or renew record, or zappetiti her(it).

Technically, this task dares as follows. In step of undertaking POST-test before entering in procedure of the processing the disc service (INT13h) is fixed the transit programme module, which analyses the input parameters to functions and детектирует two situations: attempt record in BOOT Sector and attempt of the formatting 0-y tracks. If system of the conditions is executed, instead of disc operation is given warning message and bleep. On corresponding to step of the test is executed transposition of the vector INT13h on transit controlling module if in "BIOS Setup" is enclosed givenned mode. The Givenned algorithm, depending on lace trims, can be mutated, but essence will remain former. Such a image BIOS traces the situation and when functioning(working) the operating system.

The Option is entered for protection from so named boot-virus, striking load sector. The Standard actions herewith - a start антивирусных programs, first of all with protected diskettes.

This option must be is without fall disconnected when formatting the hard disk, when entering the command "FDISK /MBR", at installations of the operating systems. Besides, some diagnostors when referencing to boot-sector can bring appearance of reports on "viral attack" that does not reflect the current situation. Using to this functions there is no point in the event of use SCSI- and ESDI-disk since they use own BIOS on kontpollepe.

One more from possible variant of the parameter can be importance "ChipAway", on the one hand this importance - an analogue "Enabled", with other - one of the variant built-in антивируса. At start of the machine is removed inscription "ChipAway Virus Enabled" that must not scare the user.

Memory Test Tick Sound

The Option, allowing accompany the test to memories by periodic bleeps. It Is Recommended install in "Enabled" for озвучивания process of the boot and additional acknowledgement, in particular, correctness of the installation "CPU clock speed/Turbo switch".

Security Option

The Option, allowing limit the access to system and to "BIOS Setup", or only to "BIOS Setup". The Choice "System" blocks boot the computer and access to "BIOS Setup". Input in system then possible only when entering the correct password. The Choice "Setup" does not lead to blocking the boot PC, but blocks input in "BIOS Setup". By default - "Setup". Both specified importances considered options can be actuated in that event only if in main menu system BIOS is simultaneously given password for manager and user.

Initial testing the computer

Quick Power On Self Test

The Quick test of the computer after power-up. The Permit of this parameter brings about некоторому to reduction of time for initial самотестирование computer POST, particularly under significant volume of the operative memory. Follows only to take into account that memory, for instance in this case is not tested, but is only checked her(its) size. The Reduction of time of the testing occurs to account of the skipping of some points of the check also. If functioning PC appear some problems, that better under his(its) cut-in to realize the full test.

Option ROM Scan

By means of given options user can allow or forbid system BIOS to realize searching for and initialization additional BIOS, located on plug-in card. The Option is used, as a rule, when work with interface SCSI for initializing BIOS, residing on SCSI-controller. When boot through network searching for is realized on network board.

Determination load device operating system

Boot Sequence

The Sequence of the bootstrap of the system. The sequence of the questioning the drives is Defined for boot the operating system. These device are marked or letter for physical hard disk and usual spindle, or name device, for instance "CDROM" for drives CD-ROM. They Are Supported device LS-120, Iomega ZIP, ATAPI CD-ROM, IDE- and SCSI-disks.

Boot Up Floppy Seek

Searching for of the spindle when boot the computer. So possible translate the name to this functions. But sense to functions vastly broader since BIOS checks, there is spindle for diskettes and goes speech about 40- herewith or 80-тидорожечном spindle. Is it Herewith provided check to capacity to work spindle flexible disk. Since all modern spindles have 80 tracks (since 1993 spindles on 40 tracks are not released. They supported the format in 360 KB), that this function unnecessary.

Necessary to notice that BIOS can not define the difference between 720K, 1.2M, 1.44M or 2.88M types spindle since all of these have 80 tracks. Makes sense install this option in "Disabled" (otherwise - "Enabled") that will allow to shorten general time of the testing PC after enabling.

Boot From LAN First

When installing in "Enabled" BIOS will undertake the attempt of the initial boot from network load module, previously than try be loaded with local carrier.

Swap Floppy Drive

The Transposition spindle. The Option, allowing "change the places" spindles A: and B: and do the load spindle B: (or on the contrary). The Option makes sense only at presence two spindles in computer and need to do the load spindle 5.25". At spindles are changed by places only logically, rather then physically.

Adjusting the functioning chip maternal board

APIC Mode

Here possible assign the state of working программируемо controller of the interruptions.

Auto Configuration

The Option automatic configuration parameter of the access to the main memory. The Option is usually found in sections "Advanced Chipset Setup" or "Chipset Features Setup" and allows to adjust time of the access to module of the memories in automatic mode or in "ручном" mode and in accordance with specification of the applicable modules to memories. To leave on mode of the user adjustment, it is enough to install the parameter in "Disabled". Importance " Auto" (the automatic deskside) is fixed by default.

Amongst possible fixed importances usually meet importances "60 ns" and "70 ns" for modules of the memories with corresponding to speed in nanosecond. The Option can be identified also "DRAM Auto Configuration" or " Auto Configure EDO DRAM Tim" ("tim" - timing). In the last option parameter "Enabled" has changed " Auto ", for the rest difference no.

Vastly, the greater differences turn out to be in that event, when" adjustment parameter good few escapes under option " Auto Configuration " "corresponding to section "BIOS Setup". Then automatically конфигурируются the parameters a cache-memories, the main memory, regenerations and even velocity ISA-buses.

NA# Enable

The Option of the cut-in/unhooking the signal NA (Next Address). Having Installed "Enabled", we include the mechanism an конвейеризации, under which chip signalizes the central processor about issue of the new address to memories before that else, as all data, transferred in the current cycle, will is processed. Naturally that cut-in of such mode raises system power.

Single ALE Enable

Razpeshenie single signal ALE. Nemnozhko information. Pin B28 on bus ISA - a signal BALE (Bus Adress Latch Enable - a permit of the latchup of the address). This signal of the strobing address bit. Device of the entering/output Can be used for prior preparation to liing ahead exchange by information. This line becomes active any pаз ppi appearance on bus of the address. Cost(stand)s to add that this signal was used in timeses 808x-h processor else. The Signal this is used seldom.

Installing "Enabled", actuate the single signal ALE instead of plural signal-strobe during ISA-cycles. In some degree choice parameter was clinging and to velocities of the system bus i.e. reception capacity of the system. So installation in "Enabled" could bring about deceleration of the speed видеоканала.

This function always remained it is enough "dark" function "BIOS Setup". "Disabled" is recommended.

The Option can be identified also "ALE During Bus Conversion" with possible variant of the choice:

" "Single" (single) " "Multiple" (plural)

Naturally that under stream functioning ISA-buses (i.e. plural cycles of the reading/record) предпочтительнее was installation to options in "Multiple". But what right choice was to do the user, always remained the riddle.

Some chip had support of the advanced mode, under which issue plural signal ALE was produced during single cycles of the bus. The Function BIOS herewith was identified "Extended ALE", but parameter served "Disabled" and "Enabled".

In most "ancient" version BIOS whole sense said was above comprised in options under name "Quick Mode".

I/O Voltage

By means of this options is given possibility to change the voltage of the feeding in chain of the entering/output of the processor and "north" bridge chip maternal board for the reason increasing of the stabilities of the functioning(working) the computer system, for instance, when increase the frequencies of the processor and buses.

Chipset Special Features

The Special possibilities chip. The Givenned parameter allows/forbids all new functions, come up for 430-h set Intel (HX, VX or TX) in contrast with FX. If it is installed "Disabled", chip functions as 82430FX.

Adjusting the functioning(working) the processor

System Thermal

Installing the mode of the observation for system temperature. The Choice variant for given functions small. Installation "Ignore" blocks the possibility of the translation of the central processor on safe state of working. The Parameter "Monitor" allows the system to trace the possibility of the appearance to dangerous situation.

In this instance the question is achievement CPU critical temperature, installed in field "CPU Critical Temperature". At achievement by central processor of this temperature internal frequency processor falls before value, installed in percent in field " Thermal Slow Clock Ratio".

BIOS Update

The Renovation BIOS. The Processors family P6 (Pentium Pro, Pentium II, Celeron, Xeon) have a special mechanism, named "programmed микрокодом", which allows to correct some types an error, допущенных at development and/or fabrication processor, to account of the change микрокода. The Renovations микрокода remain in BIOS and are loaded in processor in process of the execution instruction BIOS. Exactly so for BIOS maternal boards with specified above processor necessary regularly to update.

CPU Fast String

The Quick operations with lines. The Permit of this parameter allows to use some specific particularities of the architecture family Pentium Pro (Pentium II, Deshutes etc.), in particular, possibility of the caching operation with lines. It is Necessary only to understand, as in most program be to meet the condition for cut-in of this mechanism. These term is specified in documentation on any processor given family. The Parameter is recommended leave able "is Allowed".

CPU Ratio

The Option is intended for task of the factor of the multiplying worker frequencies of the central processor. To have a possibility it is correct to use this option, factor of the multiplying must be enabled.

CPU Speed

This option allows manually to install the clockrate of the central processor Auto - an automatic determination of the clockrate depending on identified under самотестировании type of the processor;

Manual - a task of the clockrate by user manually.

Processor Number Feature

The Option for installing the automatic sensing and output to information on built-in serial number of the processor Pentium III in BIOS maternal boards, supporting his(its) installation. For realization of such possibility, naturally, is required importance of the parameter as "Enabled". Importance "Disabled" is fixed In all rest events. It is fixed by default.

Stop CPU at PCI Master

When option is included ("Enabled"), functioning(working) the central processor can be suspended at moment инициирования PCI-device of the seizure of the bus. Installation in "Disabled" (by default) does not allow to break functioning CPU as buses. For interruption then can be needed use additional function "BIOS Setup".

Adjustment cache-memories

Burst Write

The Option allows or forbids the processor to use the mode Burst for writing package given in cache-memory second level.

CPU External Cache

Is permitted/is forbidden external cache of the processor. Forbid some type a cache-memories follows only as required artificially to slow functioning(working) the computer, for instance, when installing what or old plug-in card.

CPU Internal Cache

Is permitted/is forbidden internal cache of the processor. Forbid some type a cache-memories follows only as required artificially to slow functioning(working) the computer, for instance, when installing what or old plug-in card.

CPU Level 1(2) Cache

Is permitted/is forbidden cache first (second) level for processor of the architecture Pentium Pro (Pentium II, Deshutes etc.). Forbid some type a cache-memories follows only as required artificially to slow functioning(working) the computer, for instance, when installing what or old plug-in card.

CPU Level 2 Cache ECC Check

The Option of the cut-in/unhooking to correction error KESHA second level beside processor of the architecture Pentium II and above, which support this option. To example, the processors Pentium II supports correction an error, as from frequencies in 333 MHZ. ECC-correction certainly raises system reliability, but herewith her(its) functioning, as a rule, several are slowed. In some processor допущены errors, and cut-in of this mode can bring the system about sloppy functioning(working). Additionally factor to reliability plays the significant role in network environments only.

Cache Read Timing

Here is fixed importance of the delay before sensing given from cache-memories second level in mode of the waiting Wait-States. Given option can take following importances:

" 0 WS - (by default) delay before sensing is absent. It Is Recommended in most cases;

" 1 WS - is realized delay on one cycle of the waiting. This importance is recommended install under sloppy functioning cache to memories in mode Wait-Statеs.

Cache Write Cycle

This option installs processor time (in cycles), conducted on record даных in cache-memory second level.

Display Cache Window Size

Defines the size кэшируемой system memory, used for functioning(working) видеосистемы computer.

System BIOS Casheable

This option allows or forbids caching system BIOS. At importance, equal Enabled, speed of the performing the commands of the programs BIOS increases.

Adjustment to operative memory

CAS# Latency

The Delay CAS - CL. The most Most important feature of the chip to memories, defining minimum amount of the cycles of the pulsing signal from moment of the request data by signal CAS (practically - a command of the reading) before their appearances and firm sensing with output of the module to memories. Possible importances parameter:

" 2

" 3

or in tact:

" 2T

" 3T

Importance in 3 tacts is fixed by default. The Reduction of the parameter it is necessary to realize extremely carefully.

The Other name to options - "CAS# Latency Clocks".

So important feature to memories have saved its "importance" and with introducing the memories of the type SDRAM, but option became to be identified "SDRAM CAS# Latency" (or less "SDRAM CAS Latency Time").

We shall Note that smaller importance enlarges system power (installation in 2 tacts in comparison with 3-mya accelerates the system on 1-2%). It Is Recommended install smaller importance for SDRAM with speed 10 ns or better.

CPU to DRAM Page Mode

When option is installed in "Disabled", controller to memories closes the page to memories after access to her. When option is included (by default), page to memories remains to be open on event of the repeated address to her. Such state of working memories more production.

In various versions BIOS possible to find the options with alike names, but different importances parameter. For instance, "CPU to DRAM Page Mode" can give for choice of importance "Use Paging" and "No Paging". Possible and following вариации: "Always Open" and "Closes", "Page Closes", "Stays Open" and "Closes If Idle", "Normal" and "Disabled".

In some cases advanced (enhanced) mechanism functioning chip and controller to memories allows by means of additional information on open page of the memories to save her(its) certain time open even under disconnected options: "DRAM Enhanced Paging", "Enhanced Page Mode", "Enhanced Paging".

DRAM Data Integrity Mode

The Option of the cut-in/unhooking the check to wholeness to memories. Cut-in to options will allow the system to trace and correct the однобитные of the error. Will In the same way come to light two битные of the error, but without correction. Use the mode to correction error provides increase to stabilities and wholeness given in system, truth, under small lost capacity. If in system are not used ECC-modules to memories, that option must be disconnected.

DRAM RAS to CAS Delay

The Delay between RAS and CAS. During access to memories of the address to столбцам and lines are executed apart friend from friend. This parameter and defines defending one signal from the other. The Parameter can take importances:

" 3 - three tacts of the delay " 2 - two tacts of the delay Boot parameter BIOS, given by default, and output from program BIOS Setup

Load BIOS Setup Defaults

Importances parameter BIOS Setup Defaults are assigned by default and are fixed by producer of the concrete maternal board for ensuring the functioning(working) the maternal board. If you have chosen this mode, message will appear on screen, offerring press the key <Enter> for his(its) realization or key <Esc> - at refusal of this. The Mode BIOS Setup Defaults functions with certain "spare to toughness", allowing manually adjust the separate parameters of the computer system for increasing of her(its) power.

Load High Performance Defaults

The Producers of the maternal boards provide such mode raised power of the functioning(working) the computer, having provided for this several more risky importances separate parameter systems. Herewith for the reason increasing of power is tightened majority synchronizing and are reduced to minimum temporary delays. This, in turn, requires presence in system high-quality component such as adapter VGA, modules RAM-memories etc. In this case mode High Performance Defaults functions orderly, however producers recommend his(its) only as exploratory instrument for Over claqueur and advanced userses, not guaranteeing herewith permanent firm functioning(working) the computer. Message issues even About this BIOS.

In the event of malfunctions in functioning or hovering the computer in mode High Performance Defaults follows to clean CMOS-memory and return to more soft mode BIOS Setup Defaults.

Power-On Defaults

This option provides the most conservative adjusting the computer: cache out-of-work, importances Wait State maximum and etc. Having Chosen this item possible to be certain that system is loaded. If this does not occur, that, sooner whole, appeared the problems with hardware (for instance, is wrong installed jumpers on some device or component). In such event BIOS оповестит You.

Main notions and reductions

ACPI

Approximately with end 1994 each PC became to correspond to the schedule "Energy Star" (presence function энергосбережения), but BIOS computer was enriched built-in function t.n. "Advanced Power Management" (APM) - a joint standard corporation "Microsoft" and "Intel", which the first editing appeared as far back as 1992 In computer terminology "Energy Star" entered from name of the of the same name program government USA on reduction энергопотребления. The Respective logotype could get only that products, which executed the quota on spare energy.

"APM" was a first schedule for manufacturers PC, which has installed the interaction between operating system and BIOS in task of control энергопотреблением (Power Management).

"ACPI" (Advanced Configuration and Power Interface) - an interface extended конфигурирования and feeding control, replacing standard of extended control feeding (APM). ACPI - technology, being the basis of designed "Microsoft" standard энергосбережения and standard "Plug-and-Play" - "On Now".

The Schedule was developed together "Intel", "Microsoft" and "Toshiba" and represented itself new architecture "Microsoft Windows 98". The Operating system has undertaken control multiple parameter operation PC. Technology realizes control a condition systems, functioning component and энергопотреблением on base of the models event and use the programming on timer.

All this is reached facility OS and represents itself programmed input in modes энергосбережения, as well as output from "sleeping" mode from address to "mouse" or keyboard, in connection with receipts of the telephone call or removed network control, t.p. System BIOS дополнился and other multiple function, about which will is told hereinafter. The Presence in this whitsunday "Toshiba" more then explicable since problems and tasks энергосбережения came to the world desk PC from PC-note pad.

The Schedule "ACPI" was marketed "Intel" for the first time in chip 440LX with simultaneous realization of the architecture AGP.

Parallel with development and improvement technology энергосбережения, touching first of all producers chip, maternal boards, BIOS and developer of the operating systems, went the process of the improvement of the models monitor. The Standard "EPA Energy Star VESA DPMS" (DPMS - Display Power Management System) has defined the unified procedure энергосбережения and step-like switching off the monitor in three stages:

"On" (nominal state of working) >

"Standbye" (the mode of the waiting). In mode of the waiting scene on screen disappears, but internal components of the monitor function in normal mode, but энергопотребление falls before 80% from working condition > "Suspend" (the mode of the halt). In mode of the halt, as a rule, are disconnected high-tension elements, but consumption to energy drops to 30 Vt and less > "Off" ("dream"). In mode so named "VWVappear in the dreams" monitor comsumes not more than 8 Vt, but functions microprocessor beside it only. In this system procedure supervision undertakes the driver, sending corresponding to signals through graphic card. At keystroke on keyboard or motion "mouse" monitor moves over to normal state of working.

Glossary

ATX

Advenced Technologies eXtension - an extension of the format AT - designed several years back конструктив body of the personal computer and, accordingly, form factor of the maternal board. Began mass be used after appearance processor Pentium II, since maternal board for this processor are released only in format ATX (for very rare exception). The Main change from classical конструктива:

The Board bears up only on screw that raises reliability and acerbity of her(its) fastening.

The Connectors all port entering/output (printer, COM1, COM2 and etc) hard bear up on maternal board in her(its) right to upper corner moreover can be fixed the friend on the other.

The Processor (the processors) and his(its) "обвязка" are fixed on the right on interface connector that allows to install the full-size plug-in card.

The Power supply unit works out also voltage 3.3 V that saves from need to form this voltage on maternal board.

The Power supply unit is started/is switched off from special signal, which can be worked out as button of the enabling the computer, so and BIOS through corresponding to scheme on maternal board. This allows software to switch off the power supply unit (for instance, when leaving from Windows 95) and include him(it) on command from BIOS or from modem, network card etc.

The Voltage 5 V (слаботочное) always there is on maternal board if 220 V подано on power supply unit, for governing start power supply unit. So on "correct" ATX power supply unit always there is breaker 220 V, located on most power supply unit behind superblock. Under any action, requiring removing the lid of the superblock, 220 V are required WITHOUT FALL UNPLUG from power supply unit.

The Connector for connection ATX power supply unit on maternal board one and has 20 contacts.

It Is Allowed (but is not obligatory) output and connection on maternal board signal with sensor of the velocities of the rotation of the ventilator power supply unit.

BIOS

The Base system of the entering-output - a set of the base programs for check of his(its) equipment during start for boot the operating system, as well as for support of the exchange given between device. The Base system of the entering-output is kept in constant rememberring device (ROM), and thereby her(its) program can be executed when enabling the computer. Defining general computer power, program of the base system of the entering-output, as a rule, remain to be inaccessible for users.

Bus Master

Bus Master (the master of the bus,) - a possible state of working device on any bus, including on PCI. For functioning(working) in such mode device issues the request an arbitrator buses, reporting on its requirement on reception of bus control. The Arbitrator, in accordance with priority and/or sequence of the arbitration on given to bus, through determined time after request will return the calling device bus control. Workable all necessary him operations, device reports the arbitrator on liberation him buses.

On modern bus such as PCI, for reception of the access to bus ALL device pass the procedure of the arbitration, including central processor. The Possibility to be "master"-device is realized at development device hardware. The Realization of the mechanism "BusMaster" allows to communicate between itself only that component of the computer, which this at present necessary. This mechanism is used, for instance, for data communication TV-charge on video card if they both are found on PCI-bus moreover without participation of the central processor, system memory etc.

Usually, system controls the access to PCI-bus on fundamental principle - "First-Come-First-Served" (first came, the first is serviced). But possibility of the arbitration vastly broader and сложнее. Exist and different modes of the action most mechanism of the arbitration. Can be installed by t.n. mode ротации device, under which периодично is changed sequence device i.e. their priority. The Priority can turn out to be fixed i.e. some system device "for ever" gets the top priority. Under "rotation priority" (rotated) device, got supervision on bus, is assigned the lowest priority and any other device moves on step in "queue" priority upwards.

As all this is realized? In composition chip enters 8-bit ARBITRATION CONTROL REGISTER, allowing realize the characteristic, connected with arbitration on PCI-bus, as well as (beside it is enough new chip) with support of the schedule of the bus PCI 2.1. (refer to below) In modern system mechanisms arbitration, possible say, интеллектуал are visaed that has in total brought about withdrawal from "BIOS Setup" function, in accordance with user installation on arbitration. "Old" versions BIOS wholly can contain some of brought below option, able to cause the emotional thrill beside user.

CAS

Column Address Strobe - a strobe of the address column - a signal, used when work with dynamic memory (DRAM), is intended for запоминания in microcircuit DRAM address column.

DIMM

Dual In-line Memory Module - a two-party module to memories - an конструктов of the module to memories, became since 1997 actual standard for computer. Has on 84 outputs with each parties. Strictly memory, placed on module, can be as FPM or EDO so and SDRAM. The Memory in DIMM has разрядность 64 (with parity 72) of the bit and can be used singly, rather then vapour(pair), as usual SIMM.

DMA

Direct Memory Access - "direct access to memories" - a mode of the exchange given between memory and device of the entering/output, operated by special device (the controller DMA) and executed without participation of the central processor. Use of this mode vastly accelerates sending data, since excludes sending given in processor and back.

"Direct access to memories" is realized through DMA-controller - a special chip, receiving initial command on carrying given from central processor. The Channels DMA are intended for transmission array to information on 8- or 16-битным bus simultaneously. Unlike port of the entering/output channels DMA directly do not communicate with central processor, they work stright with system memory. The Whole channel DMA - 8 (from 0 before 7).

Originally DMA-controller was conceived, first of all, for unload CPU from trivial tasks, for instance, supervision floppy- spindle or hard disk. As from computer PC/AT data communication from hard disk and to he became be realized already not through channels DMA, but through programmed entering/output.

As from Intel 80386, the processors dispose the own device of memory control (MMU - Memory Management Unit), which recalculates the logical address in physical. DMA-controllers "nothing do not know" about разрядности addresses. So to have a possibility to use DMA together with virtual memory control, it is necessary to reserve as DMA-buffer some area to memories in the first мегабайте the address space, where logical and physical address coincide. In this area DMA-controller writes the data, previously than they will are copied by processor thereof buffer. This technology named double buffering, inefficient.

The Main "user" channel DMA are a sound cards, CD-ROM-spindles more early issue. In both events send rate does not exceed 500 Kb/with. Greatly possible send rate given on DMA-channel (beside 2 Mb/with) vastly overlays need 8-битной of the sound card. But if necessary to realize quick exchange by information then in this case DMA is not used - a processor undertakes control a process carrying to information, overlaying all possible abilities DMA-channel.