The selection of a microcomputer means the selection of different components of the computer. The most important components are a processor, memory (cache, hard disk, and floppy disk), monitor, operating system, and application software.
Here we describe the major components of a computer with their description below:
Choosing Processor (main components of a computer)
The microprocessor is the central component of a microcomputer and it determines the main features. It is also a major factor in determining the computer’s price as the other components of the computer must be compatible with it.
In general, the higher the processor’s clock speed, the faster the computer. However, clock speed comparisons make sense only when users looking at one brand and model of processors. For example, a Pentium III running at 750 MHz is faster than one with 650 MHz.
For selecting the PC, it is important to consider the role of the computer, both initially and in the longer term. It is always better to buy high-performance, bare-bone systems having to upgrade potential.
Memory chips have become inexpensive in recent years and the tendency of using larger programs is increasing. New versions of programs seem to grow exorbitantly requiring huge disk space and large main memory.
Thus more main memory for both RAM and cache is the better option. When buying a computer it is important to look out for slots on the motherboard for extra RAM, otherwise adding memory later becomes relatively expensive.
Program manufactures usually give the minimum requirements for the programs. Below the specified limit, a program won’t run. For satisfactory operation, considerably more memory is almost always necessary.
However, determining the actual amount requires some experience with a particular program. It is better to check with the dealer, consult computer journals, or ask an experienced user.
In almost every PC, there is some facility to expand the main memory. PC motherboard manufacturers usually equip their products with special sockets and sell standard memory modules for memory expansion.
Hard Disk Drive
As the data transfer rates have been standardized, the essential selection criterion should be the smallest possible average access time. IDE and EIDE disks were once hot sellers and are still quite popular. However, there are better alternatives now.
The special properties of the SCSI interface make it the model of choice now because of speed and higher disk capacity. Single-user computers may be equipped with an IDE Disk.
This disk combines high speed and advanced drive technology at a reasonable price. Attention should be paid to the average access time. Access times greater than 20 MS are no longer attractive. The controller and the hard disk must match.
The size of the hard disk depends on the software and the type of work to be done. The size should be about 40 GB plus. Sufficient space should be available for normal office applications at this capacity. Programs that use graphic interfaces often require large capacity.
Floppy Disk Drive
The 3.5-inch floppy disks are smaller, convenient and they have higher storage capacity than 5.25-inch floppy disks. A computer with a single drive should have a 3.5 –inch with 1.44 MB capacity. The difference can be observed between the 3.5-inch drives of various manufactures.
The mechanism for ejecting the floppy disks is poorly designed in some disk drives. Inserting and ejecting a floppy disk should be tried before buying a disk drive.
When the floppy disk drive is opened, the disk should come out just far enough to be removed easily. The loudness of the drive should also be checked. Some drives make noise, particularly when formatting a floppy disk.
CD-ROM and DVD Drive
A CD-ROM drive’s speed rating refers to how fast the drive can transfer data. For instance, a 24X drive transfer data at 3,600 kbps or 3.6 MB per second.
The faster CD-ROM drives are especially useful for playing audio and video files. A revised format for CD-ROM disks, called DVD (Digital Video Disk) has increased the capacity of CD-ROM size disk to 4.7 GB or more.
The video card and monitor from a unit and they must match. This applies not only to the type (VGA card for VGA monitor) but also to the technical characteristics.
Recommendations for monitors are similar to those for video cards. Basic equipment today should be at least a VGA Monitor with a resolution of 1024 x 768, and a refresh rate greater than 60 Hz, in non-interlaced mode. Higher resolutions are important for bigger monitors.
Currently, systems offer a special bus design that directly connects the video circuits with the microprocessors, increasing performance considerably. AGP or Accelerated Graphics Port is one of the best systems, which transfers video data much more quickly than the standard PCI interface.
To display 1600 x 1200 resolutions with a color palette of 16.7 million colors, for instance, the video card should be equipped with 8 MB of Video RAM (or VRAM).
The monitor’s dot pitch is another important issue to consider. One should not select a monitor with a dot pitch larger than 0.28mm and the smaller is the better.
Monitor quality can be imagined by displaying dark letters against a light background. The display should not flicker; a non-interlaced monitor refreshes the entire screen with each pass of the cathode gun without flicker.
Attention should be paid to the lowercase letters e, s, and a. There should not be a ring around the individual letters. It is good to have a demonstration of the monitor. Several hours of work at an unsuitable monitor can bring on headaches for the user.
The interaction between the video card and the screen or monitor is important. SVGA Cards and their corresponding monitors have become inexpensive now and the older graphics standards should not be recommended. An SVGA card can operate both with a monochrome or a color screen.
Any video card should have a refresh rate of more than 60 Hz in graphics mode. The advanced graphics applications require refresh rates of 701 Hz.
Keyboard and Mouse
Most computers come with a standard keyboard and mouse. However, someone worried about repetitive stress injury can consider upgrading to an ergonomic keyboard, such as the Microsoft Natural Keyboard.
On the other hand, any mouse that supports the Microsoft Intelli Mouse standard includes a wheel, which enables us to scroll thorough document with ease.
Sound card and speaker
Sound cards and speakers are the most important components to take full advantage of multimedia capabilities. One should select a standard sound card that offers wavetable synthesis and which uses stored samples as well as PCI interfaces.
Higher quality branded speakers with amplifier and volume control are selected for higher sound quality.
In order to connect the computer to a network, a network interface card (NIC) is essential. Some common NIC cards are 10 Mbps (10 based) or 100 Mbps (100 based) cards.
To log on to the campus network or the Internet by means of a telephone connection, one has to select a modem with maximum baud rate. Today standard is 56 kbps V.90 protocol.
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