Tech4all group blog

hi,

 

These are the questions for HP.Managed to get a few answers..check if you can get the rest...

 

Cheers n Regards,

Vinay

 

1. what is FAT? difference between fat16,fat32 systems?

FILE ALLOCATION TABLE.A table that the operating system uses to locate files on a disk. Due to fragmentation, a file may be divided into many sections that are scattered around the disk. The FAT keeps track of all these pieces.
In DOS systems, FATs are stored just after the boot sector.
The FAT system for older versions of Windows 95 is called FAT16, and the one for new versions of Windows 95 and Windows 98 is called FAT32.

2. What is NTFS file system?

Short for NT File System, one of the file system for the Windows NT operating system (Windows NT also supports the FAT file system). NTFS has features to improve reliability, such as transaction logs to help recover from disk failures. To control access to files, you can set permissions for directories and/or individual files. NTFS files are not accessible from other operating systems such as DOS.
For large applications, NTFS supports spanning volumes, which means files and directories can be spread out across several physical disks.

3. What is the advantages of NTFS over fat file system?

FAT16
The FAT16 file system was introduced way back with MS–DOS in 1981, and it's showing its age. It was designed originally to handle files on a floppy drive, and has had minor modifications over the years so it can handle hard disks, and even file names longer than the original limitation of 8.3 characters, but it's still the lowest common denominator. The biggest advantage of FAT16 is that it is compatible across a wide variety of operating systems, including Windows 95/98/Me, OS/2, Linux, and some versions of UNIX. The biggest problem of FAT16 is that it has a fixed maximum number of clusters per partition, so as hard disks get bigger and bigger, the size of each cluster has to get larger. In a 2–GB partition, each cluster is 32 kilobytes, meaning that even the smallest file on the partition will take up 32 KB of space. FAT16 also doesn't support compression, encryption, or advanced security using access control lists.

FAT32
The FAT32 file system, originally introduced in Windows 95 Service Pack 2, is really just an extension of the original FAT16 file system that provides for a much larger number of clusters per partition. As such, it greatly improves the overall disk utilization when compared to a FAT16 file system. However, FAT32 shares all of the other limitations of FAT16, and adds an important additional limitation—many operating systems that can recognize FAT16 will not work with FAT32—most notably Windows NT, but also Linux and UNIX as well. Now this isn't a problem if you're running FAT32 on a Windows XP computer and sharing your drive out to other computers on your network—they don't need to know (and generally don't really care) what your underlying file system is.


The Advantages of NTFS
The NTFS file system, introduced with first version of Windows NT, is a completely different file system from FAT. It provides for greatly increased security, file–by–file compression, quotas, and even encryption. It is the default file system for new installations of Windows XP, and if you're doing an upgrade from a previous version of Windows, you'll be asked if you want to convert your existing file systems to NTFS. Don't worry. If you've already upgraded to Windows XP and didn't do the conversion then, it's not a problem. You can convert FAT16 or FAT32 volumes to NTFS at any point. Just remember that you can't easily go back to FAT or FAT32 (without reformatting the drive or partition), not that I think you'll want to.

The NTFS file system is generally not compatible with other operating systems installed on the same computer, nor is it available when you've booted a computer from a floppy disk. For this reason, many system administrators, myself included, used to recommend that users format at least a small partition at the beginning of their main hard disk as FAT. This partition provided a place to store emergency recovery tools or special drivers needed for reinstallation, and was a mechanism for digging yourself out of the hole you'd just dug into. But with the enhanced recovery abilities built into Windows XP (more on that in a future column), I don't think it's necessary or desirable to create that initial FAT partition.

When to Use FAT or FAT32
If you're running more than one operating system on a single computer (see my earlier column Multibooting Made Easy), you will definitely need to format some of your volumes as FAT. Any programs or data that need to be accessed by more than one operating system on that computer should be stored on a FAT16 or possibly FAT32 volume. But keep in mind that you have no security for data on a FAT16 or FAT32 volume—any one with access to the computer can read, change, or even delete any file that is stored on a FAT16 or FAT32 partition. In many cases, this is even possible over a network. So do not store sensitive files on drives or partitions formatted with FAT file systems.


4. what is IRQ?

Interrupt Request Line, and pronounced I-R-Q. IRQs are hardware lines over which devices can send interrupt signals to the microprocessor. When you add a new device to a PC, you sometimes need to set its IRQ number by setting a DIP switch. This specifies which interrupt line the device may use. IRQ conflicts used to be a common problem when adding expansion boards, but the Plug-and-Play specification has removed this headache in most cases.

5. IRQ numbers for devices.

Prior to plug-and-play devices, users had to set IRQ values of devices manually when adding the device, such as a modem or printer, to a system. The following list of IRQ numbers specifies what each of the 16 IRQ lines are used for.

IRQ Number Typical Use Description
IRQ 0 System timer This interrupt is reserved for the internal system timer. It is never available to peripherals or other devices.
IRQ 1 Keyboard This interrupt is reserved for the keyboard controller. Even on devices without a keyboard, this interrupt is exclusively for keyboard input.
IRQ 2 Cascade interrupt for IRQs 8-15 This interrupt cascades the second interrupt controller to the first.
IRQ 3 Second serial port (COM2) The interrupt for the second serial port and often the default interrupt for the fourth serial port (COM4).
IRQ 4 First serial port (COM1) This interrupt is normally used for the first serial port. On devices that do not use a PS/2 mouse, this interrupt is almost always used by the serial mouse. This is also the default interrupt for the third serial port (COM3).
IRQ 5 Sound card This interrupt is the first choice that most sound cards make when looking for an IRQ setting.
IRQ 6 Floppy disk controller This interrupt is reserved for the floppy disk controller.
IRQ 7 First parallel port This interrupt is normally reserved for the use of the printer. If a printer is not being used, this interrupt can be used for other devices that use parallel ports.
IRQ 8 Real-time clock This interrupt is reserved for the system's real-time clock timer and can not be used for any other purpose.
IRQ 9 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 10 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 11 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 12 PS/2 mouse This interrupt is reserved for the PS/2 mouse on machines that use one. If a PS/2 mouse is not used, the interrupt can be used for other peripherals, such as network card.
IRQ 13 Floating point unit/coprocessor This interrupt is reserved for the integrated floating point unit. It is never available to peripherals or other devices as it is used exclusively for internal signaling.
IRQ 14 Primary IDE channel This interrupt is reserved for use by the primary IDE controller. On systems that do not use IDE devices, the IRQ can be used for another purpose.
IRQ 15 Secondary IDE channel This interrupt is reserved for use by the secondary IDE controller.


6. what is DMA channel?

Direct Memory Access, a technique for transferring data from main memory to a device without passing it through the CPU. Computers that have DMA channels can transfer data to and from devices much more quickly than computers without a DMA channel can. This is useful for making quick backups and for real-time applications.
Some expansion boards, such as CD-ROM cards, are capable of accessing the computer's DMA channel. When you install the board, you must specify which DMA channel is to be used, which sometimes involves setting a jumper or DIP switch.


7. what are the boot files of win98?
To load the first piece of software that starts a computer. Because the operating system is essential for running all other programs, it is usually the first piece of software loaded during the boot process.
Boot is short for bootstrap, which in olden days was a strap attached to the top of your boot that you could pull to help get your boot on. Hence, the expression "pull oneself up by the bootstraps." Similarly, bootstrap utilities help the computer get started.

(n.) Short for bootstrap, the starting-up of a computer, which involves loading the operating system and other basic software. A cold boot is when you turn the computer on from an off position. A warm boot is when you reset a computer that is already on.

Standalone Computer Boot Floppies
Format a floppy with the /S option. This will install the system files necessary for booting to the floppy

2. Create a CONFIG.SYS file.
The following is a simple CONFIG.SYS File. Your actual drivers would need to be added:

device=himem.sys
device=emm386.exe noems
device=cdrom.sys (Your CD ROM Driver would go here)
dos=high,umb
files=30
buffers=30


Be sure to add any third party drivers you may need to access your hard drive. This would be in a situation where you BIOS does not suppport large drivers

3. The following is a simple AUTOEXEC.BAT File.
@echo off
cls
mscdex /d:12345678 (where 12345678 is the string for your
particlar CD Drivers)

4. The following are a few Utility Files that may also come it useful. These need to be from the same version of DOS use used to format the floppy.
FORMAT.COM
FDISK.EXE
SYS.COM
HIMEM.SYS
EMM386.EXE
MSCDEX.EXE
XCOPY.EXE
DELTREE.EXE
ATTRIB.EXE
DISKCOPY.EXE

You can download a Windows98 Boot Floppy Image
1. This is a single executable that will create a Win98SE Boot Disk with CD ROM Support
2. Download this file to your hard drive (not the floppy disk)
3. Insert a floppy disk
4. Run the program from your hard drive
5. It will automatically format, copy and verify the data to the floppy disk.
This is a boot floppy that will allow you to access most CD ROM's.
It has a much faster boot time than the original since it doesn't take the time to create the RAM disk and uncompress all the utilities to it.

It automatically loads SMARTDRV which can speed up many OS installations.

It automatically assigns the drive letter X: for the CD ROM drive so you always know what it will be

There are a lot more DOS utilities that don't normally get added when you make one from Win98. For example Diskcopy, Doskey, Format, More, Sys, Edit, Chkdsk, Deltree, Extract, Updated Fdisk, Attrib, Label, Mem, Scandisk, Scanreg, Smartdrv and Xcopy.

6. There is also a CD ROM boot image you can download.

In addition to all the other DOS utilities, the CD version also has:
DELPART - For deleting DOS and NTFS partitions. Can delete extended NTFS partitions.
FDISK121 - FDISK with additional options - See the documentation, and
READNTFS - Read and Copy files on a NTFS partition.

The CD image needs to be burned using a program that recognized ISO images.


--------------------------------------------------------------------------------

Creating NT Boot Floppies
If you can't boot to NT for a variety of reasons, it might be a good idea to have made up a boot floppy before the problem arises.
1. Format a floppy from within NT

2. From the root of the C: drive, copy
Boot.ini
NTLDR
Ntdetect.com
and if you have them

Bootsect.dos
Ntbootdd.sys

3. You can use this floppy to boot if you were getting errors like NTLDR not found

8. what is the importance of BOOT.INI FILE?
The "boot.ini" is a Microsoft initialization file found on the Microsoft ... The "default" line is the default operating system that the boot.ini will load.The Boot.ini file, which is created during setup in the system root partition, contains information that Ntldr uses to display the startup menu.The Boot.ini file, which is created during setup in the system root partition, contains information that Ntldr uses to display the startup menu.


9. what is the difference between “safe mode” and “safe mode with networking”

10. what is an emergency repair disk? when dio u use it?
11. what is the difference between boot partition and system partition?
12. what is active partition?
13. what is the maximum number of primary partitions that I can have?
14. what does MBR stand for ?

Master Boot Record. a small program that is executed when a computer boots up. Typically, the MBR resides on the first sector of the hard disk. The program begins the boot process by looking up the partition table to determine which partition to use for booting. It then transfers program control to the boot sector of that partition, which continues the boot process. In DOS and Windows systems, you can create the MBR with the FDISK /MBR command.

15. what is the difference between “fixboot” and “fix mbr”?
16. what is a device driver? Explain.
A program that controls a device. Every device, whether it be a printer, disk drive, or keyboard, must have a driver program. Many drivers, such as the keyboard driver, come with the operating system. For other devices, you may need to load a new driver when you connect the device to your computer. In DOS systems, drivers are files with a.SYS extension. In Windows environments, drivers often have a.DRV extension.
A driver acts like a translator between the device and programs that use the device. Each device has its own set of specialized commands that only its driver knows. In contrast, most programs access devices by using generic commands. The driver, therefore, accepts generic commands from a program and then translates them into specialized commands for the device.

17. what are the features of xp unique to it ?(they are not found in win2000)

18. what is “SYSEM RESTORE” in xp.
If you are unable to start your system by using Last Known Good Configuration, Windows XP Professional provides safe mode, a startup option that disables startup programs and nonessential services to create an environment useful for troubleshooting and diagnosing problems. In safe mode, Windows XP Professional starts a minimal set of drivers that the operating system needs to function. Support for devices such as audio devices, most USB devices, and IEEE 1394 devices is disabled to reduce the variables that you need to account for when diagnosing the cause of startup problems, Stop messages, or system instability.
Logging on to the computer in safe mode does not update Last Known Good Configuration information. Therefore, if you log on to your computer in safe mode and then decide you want to try Last Known Good Configuration, the option to do so is still available.
Safe Mode Enables Only Essential Drivers and Services
Essential drivers and system services enabled in safe mode include the following:
Drivers for serial or PS/2 mouse devices, standard keyboards, hard disks, CD-ROM drives, and standard VGA devices. Your system firmware must support universal serial bus (USB) mouse and USB keyboard devices in order for you to use these input devices in safe mode.
System services for the Event Log, Plug and Play, remote procedure calls (RPCs), and Logical Disk Manager.
The following registry keys list the driver and service groups enabled in safe mode.


19. what is recovery console?
Recovery Console enables you to recover from the following problems:
Corrupted or deleted startup files caused by incompatible software, user error, or virus activity.
Disk problems related to damage to the master boot record (MBR), partition table, or boot sector on x86-based systems.
A partition boot sector overwritten by another operating system's setup program.

20. where is the MBR stored in hdd?

21. what are sectors and platters?
Sectors:-The smallest unit that can be accessed on a disk. When a disk undergoes a low-level format, it is divided into tracks and sectors. The tracks are concentric circles around the disk and the sectors are segments within each circle. For example, a formatted disk might have 40 tracks, with each track divided into 10 sectors. The operating system and disk drive keep tabs on where information is stored on the disk by noting its track and sector number.
Modern hard disk drives use a technique called zoned-bit recording in which tracks on the outside of the disk contain more sectors than those on the inside.
Platters:- A round magnetic plate that constitutes part of a hard disk. Hard disks typically contain up to a dozen platters. Most platters require two read/write heads, one for each side.
A sector that cannot be used due to a physical flaw on the disk is called a bad sector.


22. what are cylinders (hdd)?
A single track location on all the platters making up a hard disk. For example, if a hard disk has four platters, each with 600 tracks, then there will be 600 cylinders, and each cylinder will consist of 8 tracks (assuming that each platter has tracks on both sides).

23. what is the file system in floppy (fat12)

24. what does X stand when we say “12x” IN CASE OF A CD?

25. what is disk defragmentation?
Refers to the condition of a disk in which files are divided into pieces scattered around the disk. Fragmentation occurs naturally when you use a disk frequently, creating, deleting, and modifying files. At some point, the operating system needs to store parts of a file in noncontiguous clusters. This is entirely invisible to users, but it can slow down the speed at which data is accessed because the disk drive must search through different parts of the disk to put together a single file.
In DOS 6.0 and later systems, you can defragment a disk with the DEFRAG command. You can also buy software utilities, called disk optimizers or defragmenters, that defragment a disk.

(2) Fragmentation can also refer to RAM that has small, unused holes scattered throughout it. This is called external fragmentation. With modern operating systems that use a paging scheme, a more common type of RAM fragmentation is internal fragmentation. This occurs when memory is allocated in frames and the frame size is larger than the amount of memory requested.


26. where do I observe the IRQ conflicts?


27. what does USB stand for?
Short for Universal Serial Bus, an external bus standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play installation and hot plugging.
Starting in 1996, a few computer manufacturers started including USB support in their new machines. It wasn't until the release of the best-selling iMac in 1998 that USB became widespread. It is expected to completely replace serial and parallel ports.

28. how many devices can I connect with the usb technology?
29. what is “FIREWIRE “?(IEEE 1394)
A very fast external bus standard that supports data transfer rates of up to 400Mbps (in 1394a) and 800Mbps (in 1394b). Products supporting the 1394 standard go under different names, depending on the company. Apple, which originally developed the technology, uses the trademarked name FireWire. Other companies use other names, such as i.link and Lynx, to describe their 1394 products.
A single 1394 port can be used to connect up 63 external devices. In addition to its high speed, 1394 also supports isochronous data -- delivering data at a guaranteed rate. This makes it ideal for devices that need to transfer high levels of data in real-time, such as video devices.
Although extremely fast and flexible, 1394 is also expensive. Like USB, 1394 supports both Plug-and-Play and hot plugging, and also provides power to peripheral devices.


30. What are the different kind of ports that we know ?

31. I am not able to move the mouse pointer .what could be the problem?

32. what is POST?
Abbreviated POST, a diagnostic testing sequence run by a computer’s BIOS as the computer’s power is initially turned on. The POST will determine if the computer’s RAM, disk drives, peripheral devices and other hardware components are properly working. If the diagnostic determines that everything is in working order, the computer will continue to boot.

33. what is BIOS?
Acronym for basic input/output system, the built-in software that determines what a computer can do without accessing programs from a disk. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.
The BIOS is typically placed in a ROM chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself. Because RAM is faster than ROM, though, many computer manufacturers design systems so that the BIOS is copied from ROM to RAM each time the computer is booted. This is known as shadowing.
Many modern PCs have a flash BIOS, which means that the BIOS has been recorded on a flash memory chip, which can be updated if necessary.
The PC BIOS is fairly standardized, so all PCs are similar at this level (although there are different BIOS versions). Additional DOS functions are usually added through software modules. This means you can upgrade to a newer version of DOS without changing the BIOS.
PC BIOSes that can handle Plug-and-Play (PnP) devices are known as PnP BIOSes, or PnP-aware BIOSes. These BIOSes are always implemented with flash memory rather than ROM.

34. what is CMOS?
Short for complementary metal oxide semiconductor. Pronounced see-moss, CMOS is a widely used type of semiconductor. CMOS semiconductors use both NMOS (negative polarity) and PMOS (positive polarity) circuits. Since only one of the circuit types is on at any given time, CMOS chips require less power than chips using just one type of transistor. This makes them particularly attractive for use in battery-powered devices, such as portable computers. Personal computers also contain a small amount of battery-powered CMOS memory to hold the date, time, and system setup parameters.


35. What is a service pack?
Service packs are the means by which product updates are distributed. Service packs may contain updates for system reliability, program compatibility, security, and more. All of these updates are conveniently bundled for easy downloading.

36. what is the function of FDISK command?
A DOS and Windows utility that prepares a hard disk for formatting by creating one primary partition on the disk.


37. what are the boot files of win2000?
boot.ini, NTLDR, bootsect.dos, ntbootdd.sys ,ntdetect.com

38. what does IDE stand for?explain
Intelligent Drive Electronics or Integrated Drive Electronics, depending on who you ask. An IDE interface is an interface for mass storage devices, in which the controller is integrated into the disk or CD-ROM drive.
Although it really refers to a general technology, most people use the term to refer the ATA specification, which uses this technology. Refer to ATA for more information.


39. what is ATA?
Advanced Technology Attachment, a disk drive implementation that integrates the controller on the disk drive itself. There are several versions of ATA, all developed by the Small Form Factor (SFF) Committee:
ATA: Known also as IDE, supports one or two hard drives, a 16-bit interface and PIO modes 0, 1 and 2.
ATA-2: Supports faster PIO modes (3 and 4) and multiword DMA modes (1 and 2). Also supports logical block addressing (LBA) and block transfers. ATA-2 is marketed as Fast ATA and Enhanced IDE (EIDE).
ATA-3: Minor revision to ATA-2.
Ultra-ATA: Also called Ultra-DMA, ATA-33, and DMA-33, supports multiword DMA mode 3 running at 33 MBps.
ATA/66: A version of ATA proposed by Quantum Corporation, and supported by Intel, that doubles ATA's throughput to 66 MBps.
ATA/100: An updated version of ATA/66 that increases data transfer rates to 100 MBps.
ATA also is called Parallel ATA. Contrast with Serial ATA.


40. what id ATAPI?
AT Attachment Packet Interface, an extension to EIDE (also called ATA-2) that enables the interface to support CD-ROM players and tape drives.

41. USB HAS interrupts?yes or no if yes/no why?

42. what is daisy chaining?
daisy chain is a bus wiring scheme in which, for example, device A is wired to device B, device B is wired to device C, device C to device D etc. The last device is normally wired to a resistor called a terminator. All devices may receive identical signals or, in contrast to a simple bus, each device in the chain may modify one or more signals before passing them on.
Daisy chaining was a characteristic of RS-485, of Apple Computer's LocalTalk, and of various industrial control networks


43. can I dualboot win95 and win98?

44. what is HIMEM.SYS?
An extended memory (XMS) driver included with DOS, Windows 3.1, Windows for Workgroups and Windows 95. Windows 95 automatically loads himem.sys during start-up. With older versions of Windows, and with DOS, himem.sys must be explicitly loaded by placing a command in CONFIG.SYS.


45. what is “REAL MODE” and “PROTECTED MODE”?
An execution mode supported by the Intel 80286 and later processors. In real mode, these processors imitate the Intel 8088 and 8086 microprocessors, although they run much faster.
The other mode available is called protected mode. In protected mode, programs can access extended memory and virtual memory. Protected mode also supports multitasking. The 80386 and later microprocessors support a third mode called virtual 8086 mode. In virtual mode, these microprocessors can run several real-mode programs at once. The DOS operating system was not designed to take advantage of protected mode, so it always executes programs in real mode unless a protected mode extender is run first.



46. how many pins does a HDD connector have?

47. what is the difference between domain and workgroup?
A group of computers and devices on a network that are administered as a unit with common rules and procedures. Within the Internet, domains are defined by the IP address. All devices sharing a common part of the IP address are said to be in the same domain.
(2) In database technology, domain refers to the description of an attribute's allowed values. The physical description is a set of values the attribute can have, and the semantic, or logical, description is the meaning of the attribute.
A WORKGROUP is a collection of individuals working together on a task. Workgroup computing occurs when all the individuals have computers connected to a network that allows them to send e-mail to one another, share data files, and schedule meetings. Sophisticated workgroup systems allow users to define workflows so that data is automatically forwarded to appropriate people at each stage of a process.


48. how many pins does a floppy disk connector have?
A standard floppy drive connector contains 34-pin wholes we have listed the pins and the description of each pin below.

PIN 1 Ground
PIN 2 Unused
PIN 3 Ground
PIN 4 Unused
PIN 5 Ground
PIN 6 Unused
PIN 7 Ground
PIN 8 Index
PIN 9 Ground
PIN 10 Motor Enable A
PIN 11 Ground
PIN 12 Drive Select B
PIN 13 Ground
PIN 14 Drive Select A
PIN 15 Ground
PIN 16 Motor Enable B
PIN 17 Ground
PIN 18 Direction (Stepper Motor)
PIN 19 Ground
PIN 20 Step Pulse
PIN 21 Ground
PIN 22 Write Data
PIN 23 Ground
PIN 24 Write Enable
PIN 25 Ground
PIN 26 Track 0
PIN 27 Ground
PIN 28 Write Protect
PIN 29 Ground
PIN 30 Read Data
PIN 31 Ground
PIN 32 Select Head 1
PIN 33 Ground
PIN 34 Ground


49. what is “IP ADDRESS”
Internet Protocol. IP specifies the format of packets, also called datagrams, and the addressing scheme. Most networks combine IP with a higher-level protocol called Transmission Control Protocol (TCP), which establishes a virtual connection between a destination and a source.
IP by itself is something like the postal system. It allows you to address a package and drop it in the system, but there's no direct link between you and the recipient. TCP/IP, on the other hand, establishes a connection between two hosts so that they can send messages back and forth for a period of time.
The current version of IP is IPv4. A new version, called IPv6 or IPng, is under development.


50. what is “MAC ADDRESS”
Media Access Control address, a hardware address that uniquely identifies each node of a network. In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sublayers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network medium. Consequently, each different type of network medium requires a different MAC layer.
On networks that do not conform to the IEEE 802 standards but do conform to the OSI Reference Model, the node address is called the Data Link Control (DLC) address.



51. what does the command ICONFIG DO?
a command line tool used to control the network connections on Windows NT/2000/XP machines. There are three main commands: "all", "release", and "renew". Ipconfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, ipconfig displays the IP address, subnet mask, and default gateway for all adapters.

52. what is DHCP?explain
Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.
Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs use dynamic IP addressing for dial-up users.


53. how do I make a “PEER TO PEER NETWORK”
P2P, a type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures, in which some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler, but they usually do not offer the same performance under heavy loads.

54. what does RAM stand for ?(ROM?)
read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read.
Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. In addition, ROMs are used extensively in calculators and peripheral devices such as laser printers, whose fonts are often stored in ROMs.
A variation of a ROM is a PROM (programmable read-only memory). PROMs are manufactured as blank chips on which data can be written with a special device called a PROM programmer .


55. what is “VIRTUAL MEMMORY”?
virtual memory refers to an imaginary set of locations, or addresses, where you can store data. It is imaginary in the sense that the memory area is not the same as the real physical memory composed of transistors. The difference is a bit like the difference between an architect's plans for a house and the actual house. A computer scientist might call the plans a virtual house.

56. what are the different kinds of RAM?
ramm, acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
There are two basic types of RAM:

dynamic RAM (DRAM)
static RAM (SRAM)
The two types differ in the technology they use to hold data, dynamic RAM being the more common type. Dynamic RAM needs to be refreshed thousands of times per second. Static RAM does not need to be refreshed, which makes it faster; but it is also more expensive than dynamic RAM. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.
In common usage, the term RAM is synonymous with main memory, the memory available to programs. For example, a computer with 8M RAM has approximately 8 million bytes of memory that programs can use. In contrast, ROM (read-only memory) refers to special memory used to store programs that boot the computer and perform diagnostics. Most personal computers have a small amount of ROM (a few thousand bytes). In fact, both types of memory (ROM and RAM) allow random access. To be precise, therefore, RAM should be referred to as read/write RAM and ROM as read-only RAM.


57. what is an “EXPANSION SLOT”?
An opening in a computer where a circuit board can be inserted to add new capabilities to the computer. Nearly all personal computers except portables contain expansion slots for adding more memory, graphics capabilities, and support for special devices. The boards inserted into the expansion slots are called expansion boards, expansion cards , cards , add-ins , and add-ons.
Expansion slots for PCs come in two basic sizes: half- and full-size. Half-size slots are also called 8-bit slots because they can transfer 8 bits at a time. Full-size slots are sometimes called 16-bit slots. In addition, modern PCs include PCI slots for expansion boards that connect directly to the PCI bus.


58. what does PCI ,VESA,MCA stand for ?(their expansion I mean)
Peripheral Component Interconnect, a local bus standard developed by Intel Corporation. Most modern PCs include a PCI bus in addition to a more general ISA expansion bus. PCI is also used on newer versions of the Macintosh computer.
PCI is a 64-bit bus, though it is usually implemented as a 32-bit bus. It can run at clock speeds of 33 or 66 MHz. At 32 bits and 33 MHz, it yields a throughput rate of 133 MBps.Although it was developed by Intel, PCI is not tied to any particular family of microprocessors.
Video Electronics Standards Association,:- a consortium of video adapter and monitor manufacturers whose goal is to standardize video protocols.
Micro Channel Architecture-A bus architecture for older PCs. It is called a bus architecture because it defines how peripheral devices and internal components communicate across the computer's expansion bus. Introduced by IBM in 1987, MCA was designed to take the place of the older AT bus, the architecture used on IBM PC-ATs and compatibles. For a variety of reasons, however, the industry never accepted the new architecture.



59. what is “OSI REFERENCE MODEL”?
(1) (pronounced as separate letters) Short for Open System Interconnection, an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
Application
(Layer 7),
Presentation
(Layer 6),
Session
(Layer 5),
Transport
(Layer 4),
Network
(Layer 3),
Data Link
(Layer 2),
Physical
(Layer 1)

60. what does “TCP/IP stand for?
Transmission Control Protocol, and pronounced as separate letters. TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.

61. what is loopback address?
Loopback address is a special IP number (127.0.0.1) that is designated for the software loopback interface of a machine. The loopback interface has no hardware associated with it, and it is not physically connected to a network.

The loopback interface allows IT professionals to test IP software without worrying about broken or corrupted drivers or hardware


62. what does “MODEM “stand for? (its expansion) and its function?
modulator-demodulator. A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.
external modem can be attached to any computer that has an RS-232 port, which almost all personal computers have.


63. what does “DNS” stand for, and its function.?
Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
The DNS system is, in fact, its own network. If one DNS server doesn't know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned.

(2) Short for digital nervous system, a term coined by Bill Gates to describe a network of personal computers that make it easier to obtain and understand information.


64. while booting a system I get a blue screen ?what could be the causes?

65. what are the the different form factors of motherboard?(desktop motherboard)

66. explain “DOS MEMMORY MODEL”?

67. what are “CHIPSETS”?

68. What is L1,L2, and L3 cache?
Short for Level 1 cache, a memory cache built into the microprocessor, also called the primary cache.
Pronounced cash, a special high-speed storage mechanism. It can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching.
A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.

Some memory caches are built into the architecture of microprocessors. The Intel 80486 microprocessor, for example, contains an 8K memory cache, and the Pentium has a 16K cache. Such internal caches are often called Level 1 (L1) caches. Most modern PCs also come with external cache memory, called Level 2 (L2) caches. These caches sit between the CPU and the DRAM. Like L1 caches, L2 caches are composed of SRAM but they are much larger.

Disk caching works under the same principle as memory caching, but instead of using high-speed SRAM, a disk cache uses conventional main memory. The most recently accessed data from the disk (as well as adjacent sectors) is stored in a memory buffer. When a program needs to access data from the disk, it first checks the disk cache to see if the data is there. Disk caching can dramatically improve the performance of applications, because accessing a byte of data in RAM can be thousands of times faster than accessing a byte on a hard disk.

When data is found in the cache, it is called a cache hit, and the effectiveness of a cache is judged by its hit rate. Many cache systems use a technique known as smart caching, in which the system can recognize certain types of frequently used data


69. what is flashing of BIOS?
Upgrading the BIOS (Basic Input Output System) of your computer's motherboard, also sometimes called 'flashing,' used to be a complex operation full of potential perils for your PC. The task involved downloading the correct BIOS file, the proper CMOS chip flashing software, rebooting the PC into DOS mode, applying the correct commands and then waiting in suspense until the update finished. All the while there was a lurking danger - if something went wrong, you would be left with an essentially unusable motherboard…
The BIOS is a set of instructions contained on special type of volatile memory chip built onto your motherboard.it enables you to use the keyboard, see a display on the monitor, access the hard drive or CD drive, etc., all without the need for an operating system. The BIOS is the software that carries you from the moment you power on your computer to the point where the operating system begins to load, providing the instructions necessary to access the hard disk, memory and other hardware

70. what is the function of NIC CARD?(hwat does NIC STAND for?
NIC, an expansion board you insert into a computer so the computer can be connected to a network. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks.

71. what does SCSI stand for?explain
Short for small computer system interface, a parallel interface standard used by Apple Macintosh computers, PCs, and many UNIX systems for attaching peripheral devices to computers. Nearly all Apple Macintosh computers, excluding only the earliest Macs and the recent iMac, come with a SCSI port for attaching devices such as disk drives and printers.
SCSI interfaces provide for faster data transmission rates (up to 80 megabytes per second) than standard serial and parallel ports. In addition, you can attach many devices to a single SCSI port, so that SCSI is really an I/O bus rather than simply an interface.
Although SCSI is an ANSI standard, there are many variations of it, so two SCSI interfaces may be incompatible. For example, SCSI supports several types of connectors.

While SCSI has been the standard interface for Macintoshes, the iMac comes with IDE, a less expensive interface, in which the controller is integrated into the disk or CD-ROM drive. Other interfaces supported by PCs include enhanced IDE and ESDI for mass storage devices, and Centronics for printers. You can, however, attach SCSI devices to a PC by inserting a SCSI board in one of the expansion slots. Many high-end new PCs come with SCSI built in. Note, however, that the lack of a single SCSI standard means that some devices may not work with some SCSI boards.
The following varieties of SCSI are currently implemented: -
SCSI-1: Uses an 8-bit bus, and supports data rates of 4 MBps
SCSI-2: Same as SCSI-1, but uses a 50-pin connector instead of a 25-pin connector, and supports multiple devices. This is what most people mean when they refer to
plain SCSI.
Wide SCSI: Uses a wider cable (168 cable lines to 68 pins) to support 16-bit transfers.
Fast SCSI: Uses an 8-bit bus, but doubles the clock rate to support data rates of 10 MBps.
Fast Wide SCSI: Uses a 16-bit bus and supports data rates of 20 MBps.
Ultra SCSI: Uses an 8-bit bus, and supports data rates of 20 MBps.
SCSI-3: Uses a 16-bit bus and supports data rates of 40 MBps. Also called Ultra Wide SCSI.
Ultra2 SCSI: Uses an 8-bit bus and supports data rates of 40 MBps.
Wide Ultra2 SCSI: Uses a 16-bit bus and supports data rates of 80 MBps.


72. what do I mean by the term “PLUG AND PLAY “ DEVICES?

73. what are the different classes of IP ADDRESSES?

74. what is the difference between cold boot and warm boot?
The start-up of a computer from a powered-down, or off, state. Also called a hard boot.
Refers to restarting a computer that is already turned on via the operating system. Restarting it returns the computer to its initial state. A warm boot is sometimes necessary when a program encounters an error from which it cannot recover. On PCs, you can perform a warm boot by pressing the Control, Alt, and Delete keys simultaneously. On Macs, you can perform a warm boot by pressing the Restart button. Also called a soft boot.




75. what is “FIRMWARE”
Software (programs or data) that has been written onto read-only memory (ROM). Firmware is a combination of software and hardware. ROMs, PROMs and EPROMs that have data or programs recorded on them are firmware.

76. what is “LAN ,WAN , MAN”?

77. what does “UMA” stand for?
Short for Unified Memory Architecture. A computer that has graphics chips built into the motherboard that use part of the computer's main memory for video memory is said to have Unified Memory Architecture.
(2) Short for upper memory area, a synonym for high memory.[In DOS -based systems, the high memory area refers to the first 64K of extended memory.]



78. what are jumper settings?

79. what is the default resolution of VGA MONITOR?

80. what does TSR stand for?
Abbreviation of terminate and stay resident. Refers to DOS programs that can be memory resident (remaining in memory at all times once they are loaded). Calendars, calculators, spell checkers, thesauruses, and notepads are often set up as TSRs so that you can instantly access them from within another program. TSRs are sometimes called pop-up programs because they can pop up in applications.
When you install a TSR, you define a special key sequence (usually a control character) that will invoke the TSR program. You can then press this hot key from within any application to run the TSR program. Many programs can be installed as a TSR, but TSRs reduce the amount of memory available to other programs. In addition, not all TSRs interact well with each other. You may have difficulties, therefore, if you try to keep too many TSRs in main memory at once.
TSRs are unnecessary with multitasking operating systems such as Windows, OS/2, and the Mac OS

81. what are BEEP CODES?what does each TYPE OF BEEP CODE IMPLY?
BIOS Beep Codes
When a computer is first turned on, or rebooted, its BIOS performs a power-on self test (POST) to test the system's hardware, checking to make sure that all of the system's hardware components are working properly. Under normal circumstances, the POST will display an error message; however, if the BIOS detects an error before it can access the video card, or if there is a problem with the video card, it will produce a series of beeps, and the pattern of the beeps indicates what kind of problem the BIOS has detected.
Because there are many brands of BIOS, there are no standard beep codes for every BIOS. The two most-used brands are AMI (American Megatrends International) and Phoenix. Below are listed the beep codes for AMI systems, and here are the beep codes for Phoenix systems.

AMI Beep Codes
Beep Code Meaning
1 beep DRAM refresh failure. There is a problem in the system memory or the motherboard.
2 beeps Memory parity error. The parity circuit is not working properly.
3 beeps Base 64K RAM failure. There is a problem with the first 64K of system memory.
4 beeps System timer not operational. There is problem with the timer(s) that control functions on the motherboard.
5 beeps Processor failure. The system CPU has failed.
6 beeps Gate A20/keyboard controller failure. The keyboard IC controller has failed, preventing gate A20 from switching the processor to protect mode.
7 beeps Virtual mode exception error.
8 beeps Video memory error. The BIOS cannot write to the frame buffer memory on the video card.
9 beeps ROM checksum error. The BIOS ROM chip on the motherboard is likely faulty.
10 beeps CMOS checksum error. Something on the motherboard is causing an error when trying to interact with the CMOS.
11 beeps Bad cache memory. An error in the level 2 cache memory.
1 long beep, 2 short Failure in the video system.
1 long beep, 3 short A failure has been detected in memory above 64K.
1 long beep, 8 short Display test failure.
Continuous beeping A problem with the memory or video.



82. what are “I/O addresses”(input/output)?
Short for input/output (pronounced "eye-oh"). The term I/O is used to describe any program, operation or device that transfers data to or from a computer and to or from a peripheral device. Every transfer is an output from one device and an input into another. Devices such as keyboards and mouses are input-only devices while devices such as printers are output-only. A writable CD-ROM is both an input and an output device.

83. what are the differences between SRAM AND DRAM?
Short for static random access memory, and pronounced ess-ram. SRAM is a type of memory that is faster and more reliable than the more common DRAM (dynamic RAM). The term static is derived from the fact that it doesn't need to be refreshed like dynamic RAM.
DRAM stands for dynamic random access memory, a type of memory used in most personal computers.
While DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. In addition, its cycle time is much shorter than that of DRAM because it does not need to pause between accesses. Unfortunately, it is also much more expensive to produce than DRAM. Due to its high cost, SRAM is often used only as a memory cache.


84. : A user calls and says his PC was working fine yesterday but he turned on this morning and he is getting an error that reads "Invalid System Disk". What could be the problem?
Floppy in drive

85. what are SIMMS AND DIMMS?
Single Inline Memory Modules :-
The single inline memory module or SIMM is still the most common memory module format in use in the PC world, largely due to the enormous installed base of PCs that use them (in new PCs, DIMMs are now overtaking SIMMs in popularity.) SIMMs are available in two flavors: 30 pin and 72 pin. 30-pin SIMMs are the older standard, and were popular on third and fourth generation motherboards. 72-pin SIMMs are used on fourth, fifth and sixth generation PCs.

SIMMs are placed into special sockets on the motherboard created to hold them. The sockets are specifically designed to ensure that once inserted, the SIMM will be held in place tightly. SIMMs are secured into their sockets (in most cases) by inserting them at an angle (usually about 60 degrees from the motherboard) into the base of the socket and then tilting them upward until they are perpendicular to the motherboard. Special metal clips on either side of the socket snap in place when the SIMM is inserted correctly. The SIMM is also keyed with a notch on one side, to make sure it isn't put in backwards.

The 30 pin SIMMs are generally available in sizes from 1 to 16 MB. Each one has 30 pins of course, and provides one byte of data (8 bits), plus 1 additional bit for parity with parity versions. 72-pin SIMMs provide four bytes of data at a time (32 bits) plus 4 bits for parity/ECC in parity/ECC versions. Package bit width is discussed in detail here.

SIMMs are available in two styles: single-sided or double-sided. This refers to whether or not DRAM chips are found on both sides of the SIMM or only on one side. 30-pin SIMMs are all (I am pretty sure) single-sided. 72-pin SIMMs are either single-sided or double-sided. Some double-sided SIMMs are constructed as composite SIMMs. Internally, they are wired as if they were actually two single-sided SIMMs back to back. This doesn't change how many bits of data they put out or how many you need to use. However, some motherboards cannot handle composite SIMMs because they are slightly different electrically.

72-pin SIMMs that are 1 MB, 4 MB and 16 MB in size are normally single-sided, while those 2 MB, 8 MB and 32 MB in size are generally double-sided. This is why there are so many motherboards that will only work with 1 MB, 4 MB and 16 MB SIMMs. You should always check your motherboard to see what sizes of SIMMs it supports. Composite SIMMs will not work in a motherboard that doesn't support them. SIMMs with 32 chips on them are almost always composite.

Warning: Lately, some 16 MB and 64 MB SIMMs have been seen that are composite. These can cause significant problems with some motherboards, since they are specified to support 16 MB SIMMs on the expectation that 16 MB SIMMs will all be single-sided. You may not be able to use double-sided 16 MB SIMMs in some systems, especially older or cheaper ones.


Most motherboards support either 30-pin or 72-pin SIMMs, but not both. Some 486 motherboards do support both, however. In many cases these motherboards have significant restrictions on how these SIMMs can be used. For example, only one 72-pin socket may be usable if the 30-pin sockets are in use, or double-sided SIMMs may not be usable.

Dual Inline Memory Modules :-
computer systems. DIMMs are 168 pins in size, and provide memory 64 bits in width. They are a newer form factor and are becoming the de facto standard for new PCs; they are not used on older motherboards. They are also not generally available in smaller sizes such as 1 MB or 4 MB for the simple reason that newer machines are rarely configured with such small amounts of system RAM.

Physically, DIMMs differ from SIMMs in an important way. SIMMs have contacts on either side of the circuit board but they are tied together. So a 30-pin SIMM has 30 contacts on each side of the circuit board, but each pair is connected. This gives some redundancy and allows for more forgiving connections since each pin has two pads. This is also true of 72-pin SIMMs. DIMMs however have different connections on each side of the circuit board. So a 168-pin DIMM has 84 pads on each side and they are not redundant. This allows the packaging to be made smaller, but makes DIMMs a bit more sensitive to correct insertion and good electrical contact.

DIMMs are inserted into special sockets on the motherboard, similar to those used for SIMMs. They are generally available in 8 MB, 16 MB, 32 MB and 64 MB sizes, with larger DIMMs also available at a higher cost per megabyte. DIMMs are the memory format of choice for the newest memory technology, SDRAM. DIMMs are also used for EDO and other technologies as well.

DIMMs come in different flavors, and it is important to ensure that you get the right kind for the machine that you are using. They come in two different voltages: 3.3V and 5.0V, and they come in either buffered or unbuffered versions. This yields of course a total of four different combinations. The standard today is the 3.3 volt unbuffered DIMM, and most machines will use these. Consult your motherboard or system manual.

A smaller version of the DIMM is also sometimes seen; called the small outline DIMM or SODIMM, these packages are used primarily in laptop computers where miniaturization is key


86. WHAT DOES “PCMCIA “ stand for?
Short for Personal Computer Memory Card International Association, and pronounced as separate letters, PCMCIA is an organization consisting of some 500 companies that has developed a standard for small, credit card-sized devices, called PC Cards. Originally designed for adding memory to portable computers, the PCMCIA standard has been expanded several times and is now suitable for many types of devices. There are in fact three types of PCMCIA cards. All three have the same rectangular size (85.6 by 54 millimeters), but different widths
Type I cards can be up to 3.3 mm thick, and are used primarily for adding additional ROM or RAM to a computer.
Type II cards can be up to 5.5 mm thick. These cards are often used for modem and fax modem cards.
Type III cards can be up to 10.5 mm thick, which is sufficiently large for portable disk drives.
As with the cards, PCMCIA slots also come in three sizes: -
A Type I slot can hold one Type I card
A Type II slot can hold one Type II card or one Type I card
A Type III slot can hold one Type III card or any combination of two Type I or II cards.
In general, you can exchange PC Cards on the fly, without rebooting your computer. For example, you can slip in a fax modem card when you want to send a fax and then, when you're done, replace the fax modem card with a memory card.


87. what does SVGA,XGA ,CGA stand for?
Short for Super VGA, a set of graphics standards designed to offer greater resolution than VGA. SVGA supports 800 x 600 resolution, or 480,000 pixels.
The SVGA standard supports a palette of 16 million colors, but the number of colors that can be displayed simultaneously is limited by the amount of video memory installed in a system. One SVGA system might display only 256 simultaneous colors while another displays the entire palette of 16 million colors. The SVGA standards are developed by a consortium of monitor and graphics manufacturers called VESA.
Short for extended graphics array, a high-resolution graphics standard introduced by IBM in 1990. XGA was designed to replace the older 8514/A video standard. It provides the same resolutions (640 by 480 or 1024 by 768 pixels), but supports more simultaneous colors (65 thousand compared to 8514/A's 256 colors). In addition, XGA allows monitors to be non-interlaced.
Abbreviation of color/graphics adapter, an old graphics system for PCs. Introduced in 1981 by IBM, CGA was the first color graphics system for IBM PCs. Designed primarily for computer games, CGA does not produce sharp enough characters for extended editing sessions. CGA's highest-resolution mode is 2 colors at a resolution of 640 by 200.
CGA has been superseded by VGA systems.




88. what are pixels?what is resolution ,that is how would u define it?
Short for Picture Element, a pixel is a single point in a graphic image. Graphics monitors display pictures by dividing the display screen into thousands (or millions) of pixels, arranged in rows and columns. The pixels are so close together that they appear connected.
The number of bits used to represent each pixel determines how many colors or shades of gray can be displayed. For example, in 8-bit color mode, the color monitor uses 8 bits for each pixel, making it possible to display 2 to the 8th power (256) different colors or shades of gray.
On color monitors, each pixel is actually composed of three dots -- a red, a blue, and a green one. Ideally, the three dots should all converge at the same point, but all monitors have some convergence error that can make color pixels appear fuzzy.
The quality of a display system largely depends on its resolution, how many pixels it can display, and how many bits are used to represent each pixel. VGA systems display 640 by 480, or about 300,000 pixels. In contrast, SVGA systems display 800 by 600, or 480,000 pixels. True Color systems use 24 bits per pixel, allowing them to display more than 16 million different colors.

Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit-mapped graphic images. In the case of dot-matrix and laser printers, the resolution indicates the number of dots per inch. For example, a 300-dpi (dots per inch) printer is one that is capable of printing 300 distinct dots in a line 1 inch long. This means it can print 90,000 dots per square inch.
For graphics monitors, the screen resolution signifies the number of dots (pixels) on the entire screen. For example, a 640-by-480 pixel screen is capable of displaying 640 distinct dots on each of 480 lines, or about 300,000 pixels. This translates into different dpi measurements depending on the size of the screen. For example, a 15-inch VGA monitor (640x480) displays about 50 dots per inch.
Printers, monitors, scanners, and other I/O devices are often classified as high resolution, medium resolution, or low resolution. The actual resolution ranges for each of these grades is constantly shifting as the technology improves.




89. what is an S-VIDEO PORT?

90. what file syatems does win nt support?

91. IP ADDRESS can change BUT MAC ADDRESS IS CONSTANT TRUE/FALSE.

92. what is north bridge and south bridge when talking of a processor?

93. what is a firewall?
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
There are several types of firewall techniques: -
Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation.
Circuit-level gateway: Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.
Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.


94. what are the different flavours of win2000 operating system?

95. what is multitasking and ?what are the different types of multitasking?
The ability to execute more than one task at the same time, a task being a program. The terms multitasking and multiprocessing are often used interchangeably, although multiprocessing implies that more than one CPU is involved.
In multitasking, only one CPU is involved, but it switches from one program to another so quickly that it gives the appearance of executing all of the programs at the same time.
There are two basic types of multitasking: preemptive and cooperative. In preemptive multitasking, the operating system parcels out CPU time slices to each program. In cooperative multitasking, each program can control the CPU for as long as it needs it. If a program is not using the CPU, however, it can allow another program to use it temporarily. OS/2, Windows 95, Windows NT, the Amiga operating system and UNIX use preemptive multitasking, whereas Microsoft Windows 3.x and the MultiFinder (for Macintosh computers) use cooperative multitasking


96. what is “MUILTI THREADING?

97. What are the different flavours of win xp operating system?

98. what is “MSCONFIG”explain

99. what is SMART? Its expansion-self monitoring analysis and reporting tool
Self-Monitoring, Analysis and Reporting Technology, an open standard for developing disk drives and software systems that automatically monitor a disk drive's health and report potential problems. Ideally, this should allow you to take proactive actions to prevent impending disk crashes.
100. what is an operating system?

101. plz be aware of DOS operating system?

102. how do u access “BIOS” when the computer boots up?

103. how many IRQ’S does USB use?
IRQ Number Typical Use Description
IRQ 0 System timer This interrupt is reserved for the internal system timer. It is never available to peripherals or other devices.
IRQ 1 Keyboard This interrupt is reserved for the keyboard controller. Even on devices without a keyboard, this interrupt is exclusively for keyboard input.
IRQ 2 Cascade interrupt for IRQs 8-15 This interrupt cascades the second interrupt controller to the first.
IRQ 3 Second serial port (COM2) The interrupt for the second serial port and often the default interrupt for the fourth serial port (COM4).
IRQ 4 First serial port (COM1) This interrupt is normally used for the first serial port. On devices that do not use a PS/2 mouse, this interrupt is almost always used by the serial mouse. This is also the default interrupt for the third serial port (COM3).
IRQ 5 Sound card This interrupt is the first choice that most sound cards make when looking for an IRQ setting.
IRQ 6 Floppy disk controller This interrupt is reserved for the floppy disk controller.
IRQ 7 First parallel port This interrupt is normally reserved for the use of the printer. If a printer is not being used, this interrupt can be used for other devices that use parallel ports.
IRQ 8 Real-time clock This interrupt is reserved for the system's real-time clock timer and can not be used for any other purpose.
IRQ 9 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 10 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 11 Open interrupt This interrupt is typically left open on devices for the use of peripherals.
IRQ 12 PS/2 mouse This interrupt is reserved for the PS/2 mouse on machines that use one. If a PS/2 mouse is not used, the interrupt can be used for other peripherals, such as network card.
IRQ 13 Floating point unit/coprocessor This interrupt is reserved for the integrated floating point unit. It is never available to peripherals or other devices as it is used exclusively for internal signaling.
IRQ 14 Primary IDE channel This interrupt is reserved for use by the primary IDE controller. On systems that do not use IDE devices, the IRQ can be used for another purpose.
IRQ 15 Secondary IDE channel This interrupt is reserved for use by the secondary IDE controller.


104. what is RJ –45 and RJ-11 ?
Registered Jack-45, an eight-wire used commonly to connect computers onto a , especially . RJ-45 connectors look similar to the ubiquitous used for connecting telephone equipment, but they are somewhat wider.
Registered Jack-11, a four- or six-wire connector used primarily to connect telephone equipment in the United States. RJ-11 connectors are also used to connect some types of local-area networks (LANs), although RJ-45 connectors are more common.


105. what is he difference between SCANDISK and CHECKDISK?

106. what is system clock?

107. what is RTC?(its expansion).and its function
real-time clock.A clock that keeps track of the time even when the computer is turned off. Real-time clocks run on a special battery that is not connected to the normal power supply. In contrast, clocks that are not real-time do not function when the computer is off.
Do not confuse a computer's real-time clock with its CPU clock. The CPU clock regulates the execution of instructions.





108. the icons on the desktop appears very big ?what do I do?

109. I am buying a new computer ?what are the things I would look in to?

110. I have 2 computers ,but am not able to communicate between then,what may be the causes?

111. what is adware.spyware?
Spyware is broadly defined as any program that gets into your computer without permission and hides in the background while it makes unwanted changes to your user experience. The damage it does is more a by-product of its main mission, which is to serve you targeted advertisements or make your browser display certain sites or search results. spyware companies include Gator, Bonzi Buddy, 180 Solutions, DirectRevenue, Cydoor, CoolWebSearch, Xupiter, XXXDial and Euniverse.

Adware - programs designed specifically to deliver unrequested advertising

112. what does the POST ERROR “17xxxxx” IMPLY???

113. How do I go to device manager?

114. plz know which devices are connected to what ports and their pin no(total pins in them).