USB

USB 2.0 - Hi-Speed USB - FAQ


What is USB 2.0?
USB 2.0 is a complete overhaul to the Universal Serial Bus input/output bus protocol which allows much higher speeds than the older USB 1.1 standard did.

USB 1.1 allowed a maximum transfer rate of 12Mbits/second. That rate is now called 'USB.' Though some manufacturers label their products Full-Speed USB. Note that this seems a bit deceptive. Its easy to mistake Full-Speed for Hi-Speed.

As an aside, USB mice and keyboards need only 1.5Mbits/s to function. That performance level is also named 'USB' by the USB Promoter Group.

To sum it up, USB 2.0 specification incorporates three speeds: Hi-Speed, Full-Speed and Low-Speed. You as a consumer don't need to figure out all the jargons. Just keep in mind that only 'Hi-Speed USB' and 'USB' host and devices exist.

How do I know if my PC has USB 2.0?
You can identify whether your PC has Hi-Speed or not relatively easy. Open Device Manager and expand the Universal Serial Bus section. There should be an "Enhanced" USB host controller present.

Windows 98 systems may use a different name, because Hi-Speed USB drivers in these operating systems are not provided directly from Microsoft (Windows ME, 2000 and XP get their drivers through Windows Update).

These drivers are provided by the manufacturer, and may carry the maker's name (i.e. ADS, Belkin, IOGear, Siig, etc.). There should also be two standard version USB host controllers present as well. They are embedded in the USB chip which routes the differing USB speeds accordingly without user intervention.

There are currently 6 manufacturers of the Hi-Speed USB host silicon themselves:

• ALi (Acer Labs)
  

• Intel
  

• NEC
  

• SiS
  

• VIA
  

• nVidia (shows as "Standard" controller
  

Any other brand name that appears in Device Manager would likely be an add-in Hi-Speed USB PCI card. The makers above do not make add-in cards, but they do make the chips that are used in them.

How do troubleshoot "unknown device" error listed in Device Manager?

• The USB device or the USB adapter requires its own power source. If your USB device or adapter came with an AC power "brick", try connecting it.
  

• Here's a likely one - the front USB ports on your PC case may be misconnected. I've seen them that way from the factory. It's a good idea to check the connections against specifications. The standard order of connection is Red, White, Green, and Black. No more than 4 wires per USB bank are needed.
  

• Defective device. Do not assume that all PC components work correctly out of the box. I've seen many new USB devices that do not work. If you can, try the device on another PC.
  

• All drivers are not installed. Some devices will require installing the driver package before plugging in the device. Some devices will also require basic USB files from the Windows CD before the unit will function. The general rule is to always follow installation directions precisely and to have the Windows CD ready.
  

How fast is USB 2.0?
USB 2.0 has a raw data rate at 480Mbps, and it is rated 40 times faster than its predecessor interface, USB 1.1, which tops at 12Mbps. Originally, USB 2.0 was intended to go only as fast as 240Mbps.

How will consumers benefit from USB 2.0?
With speed 40 times more than that of USB 1.1, USB 2.0 broaden the range of external peripherals that can be used on a computer. Even with multiple high-speed peripherals connected to a USB 2.0 bus, the system will less likely to hit the bandwidth bottleneck. The new specification also inherits the current USB's Plug and Play and hot-swapping capability as well as providing backward compatibility for USB 1.1 hardware, allowing existing user base to upgrade seamlessly.

Do USB 2.0 & USB 1.1 hardware work interchangeably?
You may have heard that USB 2.0 is "backward-compatible" with USB 1.0/1.1 (Full-Speed USB). While that's true, USB 1.1 is also forward-compatible with USB 2.0. Whenever a system has USB 2.0 ports, you'll find the "Enhanced" USB controller in Device Manager, but you will also find two other USB controllers. These two to maintain backward compatibility to USB 1.1 devices. Each USB 2.0 host actually has 3 chips onboard. The USB controller routes signals to the correct controller chip depending on how a device is recognized. Where a device is physically plugged in has no bearing on how it is routed. All ports on a USB 2.0 motherboard can host any USB devices at all as long as the system and devices are healthy.

The vast majority of USB 2.0 devices will work on older PCs and Macs. None should flat-out fail unless there are other issues with the system. Hi-Speed USB devices will revert to Full-Speed operation when connected this way. Understand that Hi-Speed is at least ten times faster than Full-Speed in actual operation, so the speed difference is quite noticeable - unless you have never experienced Hi-Speed, of course.

When it comes to USB hub compatibility between USB 2.0 and USB 1.1, here some facts:

• A powered hub is always preferable to unpowered.
  

• USB hub ports are not as capable or flexible as real PC ports so it's best not to expect the world of them.
  

• USB 1.1 (obsolete) hubs will work fine on USB 2.0 ports, but they cannot utilize USB 2.0 capabilities. They will default to slower speeds.
  

• Hi-Speed and Full/Low-Speed USB devices can coexist nicely on USB 2.0 hubs. Connecting such a hub to a USB 2.0 port is recommended.
  

• USB 2.0 hubs can be used on older USB 1.1 computers.
  

• Although it is said that you can "cascade" up to 4 hubs, problems may start to arise after two hubs, it's best to minimize hub usage if possible.
  

• Many USB devices don't work well on hubs. Cameras, scanners and especially USB drives are known to have problems with hub connectivity.
  

• Remember that "active USB extensions" are really just one-port hubs.
  

Will USB 2.0 replace USB 1.1?
Not entirely, because many products such as generic keyboards, mice, joysticks and audio speakers do not require the faster speed of the new USB 2.0 technologies. Only bandwidth-hungry devices, such as web cams and high-capacity storage systems, will need all the speed. However, next-generation systems will come with USB 2 ports rather than USB 1.1.

How do I distinguish between a USB 2.0 and a USB 1.1 devices? New logos designed by the USB Promoter Group allow consumers to easily identify the new USB 2.0 products. The new colorful logo for USB 2.0 is labeled USB Hi-Speed, and the new logo for USB 1.1 is labeled with USB Basic Speed. However, most people won't miss it as manufacturers often label USB 2.0 READY Or 40 times faster than USB 1.1, on the boxes.

Will USB 1.1 devices run any faster on a USB 2.0 bus?
No. However, the new USB 2.0 archiclecture allows more high-speed USB 1.1 devices, such as web cams, audio devices, to share the bandwidth. Developers need to follow USB 2.0 spec in order to design higher speed peripherals that can take advantage of the extra bandwidth. USB 1.1 devices still operate at 12Mbps at full-speed and 1.5Mbps at low-speed on a USB 2.0 bus. Even though USB 1.1 devices won't run any faster, they can work alongside of USB 2.0 devices on the same bus.

What are USB Hi-Speed and USB Basic Speed logos?
These logos are part of USB Promoter Group's branding program that ensures the quality of USB products. The USB 2.0 certified products would display a blue, white and red logo, bearing the words Certified and Hi-Speed. The classic USB 1.1 certified products would display a black and white logo with the words USB and Certified.

Under a license from USB-IF, products must pass the compliance tests before manufacturers can use one of the two trademarked logos. The Promoter Group will take legal actions on manufacturers that label either logo on their products, which have not passed the tests.

What happen if a USB 2.0 devices are plugged into a USB 1.1 systems?
The entire bus under the USB 1.1 root hub will slow to 12Mbps. The operating system will probably notify the user about the sub-optimal configuration and recommend for a better course of action.

If several USB 1.1 hubs are connected to a USB 2.0 bus, then each of the USB 1.1 hubs will get a full 12Mbps bandwidth.

What is the max? Length of a USB 2.0 cable?
5m. however, if you cascade 5 hubs with 5m USB cables, this will allow you to connect a device 30m away.

What do I need to use a USB 2.0 device?
The requirement is similar to that of USB 1.1, but all components will have to be USB 2.0 compliant. A successful USB 2.0 connection requires a USB 2.0 host controller card, a USB 2.0 driver and a USB 2.0 peripheral.

How much will it cost to upgrade to USB 2.0?
Around $80 to $150. Currently, Orange Micro., Adaptec and IO Gear are shipping USB 2.0 PCI cards, some of which even have FireWire ports. Interestingly, almost all USB 2.0 PCI cards include an internal port, which is probably for connecting internal USB 2.0 IDE enclosure or USB 2.0 front panel.

Will USB 2.0 arrive on mobile computers?
Yes, but not in integrated solution on laptops. You will need a USB 2.0 Card Bus card. Orange Micro. is shipping USB 2.0 compliant 4-port Card Bus card. Eventually, notebook vendors will adapt to USB 2.0 technology, and we will see USB 2.0 ports on laptops. This transition won't happen until 2002 at the earliest.

Which operating systems support USB 2.0?
Microsoft has released the official USB 2.0 driver for Windows XP and Windows 2000. The version is 5.1.2600. The software is available on-line at Windows Update website. (If you don't have a USB 2.0 card installed in your system, Windows Update won't list the USB 2.0 driver as an update.)

The software company is still considering USB 2.0 support for Windows ME, but it already has decided not to bring USB 2.0 to Windows 98 and Windows 98 SE. If you have Windows 98, you will have to rely on 3rd party USB 2.0 support from USB card manufacturer.

Do USB 1.1 cables work with USB 2.0 devices?
Ideally, yes. USB 2.0 architecture uses the same cables and connectors as USB 1.1 compliant products. Unfortunately, only 3 out of 11 cables on the market are certified as USB 1.1 compliant. You may run into the cables that cause problems connecting high-speed peripherals. To avoid negative user experience, most vendors include USB 2.0 compliant cables with their USB 2 PCI cards and peripherals.

Safer Registry Editing Tips

Make sure before modifying your system Registry about its backup and you need to know how to organized the registry, how to perform the basic editing, because Registry contains all information how your system runs. This backup will help you to restore Registry in case any problem occurs after modifying. Learn how you can Export and Import Registry File before Editing?

You can backup the whole Registry and only Registry subkeys also.

Click Start Button then type regedit in Run dialog box and click Ok button. Here you can backup the whole Registry or you can locate the required subkeys that contain the information that you want to edit.

Go to File menu option then click on Export option for backup and save it with on any your system drive with .reg extension and you can restore this backup going File menu using import option.

Database Tips

What is database?

A database is a collection of related data stored in an efficient and compact manner. The word “efficient” means that stored data can be accessed very easily and quickly.

Similarly, the word “compact” means that stored data takes up as little space as possible. In the above definition of database, the phrase “related data’ is used. It means that a database contains data or information about a particular topic such as:

• Database of employees that contains data of employees of an organization or department.
  

• Database of students that contains data of students of college or university.
  

A database holds related data as well as description of that data. For this reason, a database is also defined as a self describing collection of integrated records. The description of data is known as the system catalog or data dictionary or metadata. For example when a table of a database is designed, the data type, size, format and other descriptions of fields are specified. This is an example of metadata, which describes the properties of data to be stored into fields of table.

The data of any organization is its integral part. The data is very important for developing new products and their marketing. The data must be accurate and available when needed. This is the reason that all organization must organize and manage their data into database. The databases are used for variety of purposes in as organization. For example, when you purchase goods from your local supermarket, the checkout assistant will pass the purchased product through a scanner device known as bar code reader. This device will read the bar code printed on the product and gives the accurate price of the item. Actually, the bar code reader is accessing the database, which contains the information about the products. The bar code reader is linked to a database application program, which uses the bar code to access price of item. The database program automatically updates the database. The assistant can also check whether a required item is in stock by running the database application program. Similarly, you can purchase goods using your credit card. Your credit is checked by a card reader linked to a computer system. In this case, there is a database somewhere that contains information about your credit. Almost all organizations and government departments of every country in world use database to maintain their records. Some examples of large databases that have been developed around the world are:

• When you draw amount from bank through ATM card, you are accessing the database; your account is accessed and checked through auto teller machine. When you draw some amount from your account, your record in the database is automatically updated immediately.
  

• When you visit your local library, there may be a computerized database containing details of the books in the library. There will be a computerized index, which allows you to find a book based on its title, its author’s name etc.
  

• The meteorological organization contains databases having information about current and previous meteorological data. The meteorological department is totally dependent on the meteorological data.
  

A database may be generated and maintained manually or it may be computerized. The library card catalog is an example of a database that is created and maintained manually. On the other hand, a computerized database may be created and maintained either by using application program, which is developed specifically for that purpose or by a database management systems.

Browsing Your Computer via the Address Toolbar Tips

Here is a very cool tip to open your system drive and web page quickly. You can open any web page without opening browser, windows will automatically open your windows browser and open your web page. you can do this if you put an Address Bar on your Taskbar.


Right click on your system taskbar > go to Toolbars and then click no Address option, here you will see a mark on Address option. After this a Address Bar will appear on your system Taskbar, you can open any web page by typing URL name here and press Enter, Windows will automatically open your web page in be default set browser.

You can also browse files and folders on your computer by using the Address Bar. simply type drive letter like C:\ , D:\ in Address Bar and Press Enter.

C:\

Fake Windows Update Email

Well Microsoft believes that the grace period is over and wants everyone to jump on board and get Service Pack 2 (SP2) installed. I know everyone has an opinion on the Service, some good some not so good, but it really is only a matter of time. Do you know anyone without SP1 on his or her XP machine? I hope not.

As you may also know, Microsoft has picked the second Tuesday of the month to run their new security patches. These two issues have really set the stage for a new attack on windows users. Hackers have decided to try and slip one by your defenses with a Phishing/Trojan scam. You may get a spoof emails that link to a bogus Microsoft site where the hackers get you. If successful in their efforts, the ambushed PC will be infected with the TrojDSNX-05, a back door Trojan that attempts to gain control over your system. With control of your system the hacker will more than likely use you (of course unknowingly) as a spam server to mail out huge amounts of spam in your name. If a network PC happens to get infected, then a denial of Service, exploitation of network shares, and further infection are something you may look forward to.

The TrojDSNX-05 is not the newest virus on the block and can be controlled if you have decent anti-virus software that is up-to-date.

Microsoft will never send you an email reminding you to update.

Very similar to the fact that companies will never send you an email asking you to reply with your credit card and account info in order to fix some discrepancy with your account. In fact, if you ever receive any emails that seem "Phishy" to you, try going directly to the company web site (not the link in the email) and see for yourself what's going on.

As far as SP2 goes, if you haven't installed it yet I suggest doing it on your own terms, backup all your important data (pictures of the family, documents, whatever is important) set a system restore point. Go out to the manufacturer's site of your favorite programs and see if there are any known issues, FAQ's, or patches. If so, follow the instructions to properly install any necessary components and follow any necessary procedures in the exact manner in which the instructions describe. After this you should have all your bases covered, and feel comfortable installing SP2.

Motherboard Cleaning Tips

Motherboard is the main part of your computer that contains all hardware components. Your computer motherboard could fry, if you do not keep it clean on periodically basis. Dust is the main cause to heat up your system and heat link to hardware failure. You can save your computer maintenance cost if you clean your computer on the regular basis. This will improve the cooling and performance of the motherboard components.

• To clean your motherboard first unplugs your system power from the electrical outlet.

• Using the screwdriver remove the side covers of your computer case and put them to one side.

• Check all data and power cables connections. Inspect all motherboard PCI and AGP slots.

• Remove all add-on card of your motherboard for example RAM, modem, VGA, sound card and LAN card.

• Now blow the air around all the motherboard sides and keeping away your blower nozzle 4 to 5 inches away from main board components. You can use vacuum cleaner also for this purpose but compressed air is the better solution to clean a system.

• At the end assemble back all cards, cables and side covers of your system.

• I recommend you doing this after every three months if you want to save your system life.

Automatic Screen Refresh Tips

When you are working on your local computer and want to refresh any changes in your system automatically. For example some times you are watching sports results, online Stock Exchange rates and any changes to your hard drive but these changes are not usually refreshed until you press the F5 key on your keyboard.

To refresh your screen automatically you should edit your system Registry. But the best technique to edit the windows registry keys, always export or backup the whole windows registry keys on backup drive before editing. Because any mistake in Registry can cause serious problem in your computer to run properly.

Follow the given steps to change the updates automatically.

• First click on Start button then type Regedit in Run option.

• In Registry Editor panel go to the path:
  

• HKEY_LOCAL_MACHINE / System / CurrentControlSet /Control / UpdateMode
  

• Here in right hand side panel edit the DWORD value to be between 1 and 5.

• Now restart your computer after any changes to go into effect.

Clean computer Casing Tips

When you noticed your computer case is looking yellowish then you can understand about inner side of your computer case as dirty as outside. Because Dust is the main cause to heat up your system and heat link to hardware failure. You can save your computer maintenance cost if you clean your computer on the regular basis.

• Never place your computer on the ground, always use computer table or shelf for this purpose.
  

• To clean computer case first unplugs your system power from the electrical outlet. Remove all cables and connectors from the back side of your computer.

• Now use the compressed air and start clean from back to front of your computer case, specially casing and power supply fan.

• At the end using lightly dampened cloth or spray any cleaning fluids on the computer case and use paper towel to dry it.
  

• This process should be done after every three months if you want to save your system life.

General Cleaning Tips

You can save your computer maintenance cost if you clean your computer on the regular basis. This will improve the cooling and performance of the computer components. Your computer components could damage, if you do not keep it clean on periodically basis, because dust is the main cause to heat up your system and heat link to hardware failure.

• Never place your computer on the ground, always use computer table or shelf for this purpose.

• To clean computer case first unplugs your system power from the electrical outlet. Remove all cables and connectors from the back side of your computer.

• Now blow the air around all the hardware components and keeping away your blower nozzle 4 to 5 inches away from main board components. You can use vacuum cleaner also for this purpose but compressed air is the better solution to clean a system.

• At the end using lightly dampened cloth or spray any cleaning fluids on the computer case and use paper towel to dry it.

• Never clean inside computer components or other circuit board with damp or wet cloth.

• Always be careful to eat or drink around the computer.

SCSI Disk

1. Disk SCSI (Small Computer System Interface) IDE with similar organizations in addressing.
2. Differences in the tool interface capable of transferring data in high speed.
3. High-speed transit, is a standard for computers.
4. UNIX from Sun Micro systems, HP, SGI, Machintos, Intel, especially computer-server computer network, and vendor-other vendor.
5. SCSI is actually more than just a tool interface hard disk.
6. Each device has a unique ID as a media introduction by the SCSI.
7. SCSI is a bus as capable as a checker to 7 equipment such as:
   

• Hard
• CD-ROM
• CD-Recorder
• Scanner music, n traveling.

SCSI Disk Version

RAID

RAID level 0

1. Actually not use RAID redundancy does not improve in performance.
2. Data distributed on the entire disk array, is the advantage of using a large capacity disk.
3. RAID - 0 become a model of the data strip on the disk with a data management system specific to the data stored on considered a logical disk.
4. Mechanism for the transfer of data in one sector at a time so that only good for handling large data transfers.
   

RAID level 1

1. Redundancy obtained by duplicate all the data on the disk mirror.
2. As with RAID - 0, RAID - 1 stripping also use the technology.
3. The difference is in level 1 each strip mapped to the logic of the two disks that are logically separate so that each disk arrays will have a mirror disk that contains the same data.
4. RAID - 1 expensive.
5. RAID - 1 increase in performance approximately doubled compared to RAID - 0 in the operation read, but not to write operations significantly increased.
6. Matches are used to handle data that is often experienced failure in the process of reading.
7. RAID - 1 still working on sector-sector.
8. Benefits of RAID - 1:

• Request reading can be served by one of the disk because there are two disks contain the same data, depending on access to the fastest time.
• Demand for storage or writing is done on 2 disks in pararel.
• There are beack-up data, namely the disk in the mirror.
  

RAID level 2

1. RAID - 2 using the technique pararel access to all the disk. - All participating disk and executing every request so that there are mechanisms for synchronization and disk rotation head.
2. Technology used in the stripping this level, only strip small size, often in word or byte size.
3. Use a system error correction bits parity with the Hamming code.
   

RAID level 3

1. Organized similar with RAID - 2.
2. The difference in RAID - 3 requires only a single disk redudant, does not depend on the number of arrays disk.
3. Computing parity bit for each word and write data on disk pritas special.
4. When the drive failure occurs, the data re-arranged the rest of the data is still good and from information paritasnya.
5. Using pararel access to the data distributed in the form of small strip-strip.
6. Performing high-yield transfer, but can only executing a request.
7. I / O, so only if used in high data transaction environment decline in performance.
   

RAID level 4

1. Using techniques that independent access to every request so that disknya read or write served in pararel.
2. RAID is suitable to deal with the culture system data transfer rates.
3. No need synchronization because each disk operate independently.
4. Stripping the data in a large size.
5. Strip parity bits-per-bit is calculated to strip all the related data on each disk.
6. Parity stored on disk for parity.
7. When the writing operation, array management software not only to update the data but also related to parity.
8. Benefits of parity with the disk that has made special security data more secure, but with a separate disk parity will slow performance.
   

RAID level 5

1. Having a similarity with RAID - 4 in the organization.
2. The difference is strip-strip parity distributed across the entire disk.
3. For security reasons, the strip parity disk is stored on a disk other.
4. RAID - 5 improvement from the RAID - 4 in terms of improving performance.
5. Disk is usually used in the network server.
   

RAID level 6

1. It is the latest RAID technology.
2. Using the method of calculating parity for two reasons to anticipate the accuracy and error correction.
3. As with RAID - 5, parity stored on the disk other.
4. Have a high transfer speeds.

RAID Images

Tape Magnetic Emissions

• System using the technique of magnetic tape reading and writing, which is identical with the magnetic disk system.

• Medium magnetic tape, a track pararel, the old tape system bears fruit 9 tracks that allows storage one byte at a store one bit of parity on the remaining tracks.

• The system uses a new tape, 18 or 36 tracks as an adjustment to the width of word in a digital format.

• As the disk, magnetic tape, read and written in the form of blocks connected (continue), which is called physical records.

• Block-block is separated by gaps called inter-record gaps.

• Head magnetic tape is a sequential access device.

• Head must adjust the location of records that will be read or written.

• When the head is in place more of the desired records from the tape need rewind first, the new reading is done with the forward direction.

• Very different technology on the disk using the techniques of direct access.

• Lap speed magnetic tape is low so that the transfer of data to be slow.

• Pita begin magnetic abandoned replaced by the type of CD products.

Database Tips

What is database?

A database is a collection of related data stored in an efficient and compact manner. The word “efficient” means that stored data can be accessed very easily and quickly.

Similarly, the word “compact” means that stored data takes up as little space as possible. In the above definition of database, the phrase “related data’ is used. It means that a database contains data or information about a particular topic such as:

• Database of employees that contains data of employees of an organization or department.
• Database of students that contains data of students of college or university.
  

A database holds related data as well as description of that data. For this reason, a database is also defined as a self describing collection of integrated records. The description of data is known as the system catalog or data dictionary or metadata. For example when a table of a database is designed, the data type, size, format and other descriptions of fields are specified. This is an example of metadata, which describes the properties of data to be stored into fields of table.

The data of any organization is its integral part. The data is very important for developing new products and their marketing. The data must be accurate and available when needed. This is the reason that all organization must organize and manage their data into database. The databases are used for variety of purposes in as organization. For example, when you purchase goods from your local supermarket, the checkout assistant will pass the purchased product through a scanner device known as bar code reader. This device will read the bar code printed on the product and gives the accurate price of the item. Actually, the bar code reader is accessing the database, which contains the information about the products. The bar code reader is linked to a database application program, which uses the bar code to access price of item. The database program automatically updates the database. The assistant can also check whether a required item is in stock by running the database application program. Similarly, you can purchase goods using your credit card. Your credit is checked by a card reader linked to a computer system. In this case, there is a database somewhere that contains information about your credit. Almost all organizations and government departments of every country in world use database to maintain their records. Some examples of large databases that have been developed around the world are:

• When you draw amount from bank through ATM card, you are accessing the database; your account is accessed and checked through auto teller machine. When you draw some amount from your account, your record in the database is automatically updated immediately.
• When you visit your local library, there may be a computerized database containing details of the books in the library. There will be a computerized index, which allows you to find a book based on its title, its author’s name etc.
• The meteorological organization contains databases having information about current and previous meteorological data. The meteorological department is totally dependent on the meteorological data.
  

A database may be generated and maintained manually or it may be computerized. The library card catalog is an example of a database that is created and maintained manually. On the other hand, a computerized database may be created and maintained either by using application program, which is developed specifically for that purpose or by a database management systems.

CPU Functions

CPU functions

• Running programs - programs that are stored in the main way to take instruction - instruction, testing and instruction exsecution one by one according to the groove.
• The view most simple program execution process is to take the processing instruction that consists of `two steps, namely:

* Operation reading the instructions (Fetch)
* Operation of instruction (execute)

Instruction cycle

• Consists of Fetch cycle and the cycle execution

Fetch cycle - execution

• At each cycle instruction, the CPU will initially read instructions from memory.
• There are registers in the CPU, which functions control and calculate the next instruction, called the Program Counter (PC)
• PC will add one calculation each time the CPU to read the instructions.
• Instructions - read the instructions that will be made in the Instruction Register (IR).
• Instructions - in the form of this instruction code - the code binner the interpretation can be done by the CPU and the action required.

The CPU Action

1. CPU - Memory, the movement of data from the CPU to memory and vice versa.
2. CPU and I / O, the movement of data from the CPU to the module I / O and vice versa.
3. Data processing, the CPU establish a number of arithmetic and logic operations of the data.
4. Control, is the instruction to control functions or work. For instance affairs conversion instruction execution.

Details cycle execution

• Instruction Address Calculation (IAC), namely Calculation or determine the address of the next instruction that will be executed.

• Involving the number of permanent additions to address previous instructions.

>> For example, if the length of each 16 bit instructions have
a long memory when 8 bits, then add 2 to address previously.

Cycle execution

• Cycle for an instruction execution can involve more than a reference to the memory.
• In addition, an instruction can determine an operation I / O.
• Instruction Fetch (IF), read the instructions from the authorities or the location of memory to the CPU.
• Instruction Operation Decoding (IOD), which analyzes the instructions to determine the type of operations that will be formed and operand that will be used.
• Operand Address Calculation (OAC), which determine the address operand, this is done when the reference operand involved in memory.
• Operand Fetch (OF), is taking operand from memory or from the module I / O.
• Data Operation (DO), which is formed in which the operating instructions.
• Operand store (OS), the results of execution to save the memory.

Figure cycle instructions


Function Interruptions

• Mechanism termination or transfer of the processing instructions in the CPU to the routine interruptions.
• Almost all modules (memory and I / O) have a mechanism that can work to interrupt CPU.
  

Goals Interrupts

• In general, for management execution routine instructions to effective and efficient inter-module and the CPU - the module I / O and memory.
• Each component of the computer can run tasks simultaneously, but the control is located on the CPU in addition to the speed of execution - each module is different.
• Can work as the synchronization between the modules

Kind of class signal interruptions

• Program, the interruptions are raised with several conditions that occur on the results of program execution.

* Example: aromatic overflow, the division of zero, operation illegal.

• Timer, is the interruption of the timing raised in the processor.

* Signals allows operating systems to run certain functions regularly.

Kind of class signal interruptions

• I / O, signal interruptions that are raised by the module I / O notification in respect of conditions of error and a resolution of the operation.
• Hardware failure, is raised by the interruption of power failure or memory parity errors.

The process Interrupt

• With the mechanism interruptions, the processor can be used for executing other instructions.
• When a module is finished and ready to run the duty to receive the next assignment, the module will send a request interruptions to the processor.

The process Interrupt

• Then, the processor will stop the execution of run to manhandle routine interruptions.
• Once the program is completed, the interruption processor will continue the program execution again.
• When interruptions received signal processor there are two possible actions, namely interruptions accepted or rejected suspended and interruptions.

Interruptions Suspended
What do processors?

• Processors suspend the execution of programs that run and save the context. This is the address of store instructions that will be exercised and other relevant data.
• Processors set the program counter (PC) to address early routine Interrupt handlers.

Cycle execution by the processor with the function of interruptions


Operating system complex

• Interruption double (multiple Interrupt).

* For example, a computer will receive the request interruptions
during the printing process is completed with
the printer, in addition to the possible channels
of communication will submit a request
each time the interruption of data arrived.

• Can be taken two approaches to handle this double interruption.

Interrupts dual approach
There are 2 approaches:

• This approach is called sequential processing interruptions / sequential.

* Reject or other interruptions do not allow the interruption of a processor handled.
* Once completed processor handles the interruption of a new handled other
interruptions.

Interrupts dual approach

• Processing interruption nest that is defining priorities for the interruption.

* Interrupt Handler: allow interruptions priorities higher handled first.

Multiple Interrupts - Sequential


Multiple Interrupts - Nested


Case

• A system has three devices I / O: printers, disk, and communication channels, each - their priorities 2, 4 and 5. How will the process interruptions?
• At the beginning of the printing system with a printer, when there is data on the delivery channel of communication so that communication module to request interruptions.
• The transfer of the execution of interruption of communication modules, the printer interruptions while suspended.
• When execution communication module, the interruption disk, but a lower priority because of the interruption suspended disk.
• After the interruption of communication modules will be completed by interruptions that have higher priority, namely the disk.
• When the disk is finished interruption, the execution interruptions printer. `Then the execution of the main program.

CPU (Central Processing Unit)

CPU

• Central Processing Unit.

• It is the most important components of the computer system.

• Components of data processing based on the instructions given to him.

• In creating the functions and tasks, the CPU composed of several components.

Main components of the CPU

• Arithmetic and Logic Unit (pestle)

• Control Unit

• Registers

• CPU Interconnections

CPU Chart


Arithmetic and Logic Unit (pestle)

• The task of shaping functions - data processing functions of the computer.

• Pestle is often called the machine language because the instructions do this - the machine language instructions given to them.

• Pestle consists of two parts, namely the unit and the unit arithmetic Boolean logic, that each - each have the task specification work.

Control Unit

• Duty to control the operation of the CPU and the overall control the computer so that the synchronization of work between the components in the run function - a function of operations.

• Included in the responsibilities of the unit is to take control instructions - instructions from main memory and determine the type of instruction.

Registers

• Media storage internal CPU that is used when processing data.

• Memory is temporary, usually in use to store data when the data is processed or for further processing.

CPU Interconnections

• System connection and a bus connecting the internal components and a bus - the bus external CPU.

• CPU internal components, namely pestle, the control unit and the register - the register.

• Component external CPU: other system, such as main memory, a tool inputs / outputs.

CPU internal components


Detail the structure of the internal CPU

Computer Evolution and Performance Part 12

Solutions
- Increasing the number of bits in one time

• Create greater DRAM

- Changing the interface DRAM

• Cache

- Reduce frequency access memory

• Cache more complex and is located on the chip

- Improve the bus system

• High speed buses

• Hierarchy of buses

I / O Devices
- The device needs for operation of I / O
- Need Throughput data that is large enough
- Processor can handle this task
- Problems in the transfer of data
- Solution:

• Caching

• Buffering

• High-speed interconnection buses

• More elaborate bus structures

• Multiple-processor configurations

Typical I / O Device Data Rates


The key: balance
- Processor components
- Main memory
- I / O devices
- Interconnection structures

Computer Evolution and Performance Part 9

IBM 360 Series

• Produced 1964.
• Instruction Set Similar or identical, in these various groups of computer models issued using the same set of instructions so that the support system and device compatibility severity.
• Operating System Similar or identical, this is a feature that consumers demand, so when the computer does not require the replacement of the difficulties in the operating system because the same.
  

IBM 360 Series

• The increased speeds, models are offered ranging from low speed to high speed for the use of the consumers themselves can be adjusted.
• Memory size is greater, the higher models will be increasingly large memory.
• Price increases, the higher the style then the more expensive price.
  

IBM 360 images