Different Processors View Bits example essay topic

"Computer for sale: P 150, 24 MB RAM, 2 GB Hard Drive, 12 X CD-ROM, 28.8 modem, SVGA monitor". Do computer ads seem little more than confusing gibberish? Despite all the cryptic abbreviations and explanations offered by magazines, a computer, at its simplest, is nothing more than a series of millions of tiny switches linked together. The seemingly complex computer can be easily understood by looking at the way it "thinks" (the processor), its parts (the hardware), and how to tell it what to do (writing programs). The "brain" of the computer is the processor.

The processor is made of millions of tiny electrical switches. The position of these switches direct the computer in its actions. A solitary switch is called a bit. A bit can be either on (1) or off (0). On digital, or number-based, computers, all data is recorded this way -- text, video, and sound. By combining eight bits a byte is formed.

A byte can hold one of 256 (2^8) possible values. A byte is the most common storage unit for a computer, since a byte can be used to hold one letter, number, or character. Different processors look at a different number of bits at a time, or have different word sizes. When an ad is shown advertising a "64 bit game machine" it is referring to the word size of the processor. Different processors view bits and bytes differently -- this is why an IBM program won't run on an Apple computer. Processor speed is measured in megahertz (MHz).

The number of MHz translates to how many millions of cycles the processor can make per second. A cycle is the amount of time it takes the processor to complete a single operation. For example, a processor could multiply a number by two. Everything else being equal, more MHz mean a faster computer.

Processors are assisted by co-processors -- small single tasked processors. Common co-processor functions include graphics and math. A math co-processor is signaled in computer jargon by including a "DX" after the processor's name. A 486 DX is a 486 processor with a math co-processor. Hardware is the computer's set of external components.

The most necessary piece of hardware in a computer is random access memory (or RAM). This memory creates a large electrical field where bits can be stored when the processor is not using them. Most modern computers have between 16 and 32 megabytes of RAM. A megabyte is approximately 1,000,000 bytes.

RAM's great weakness is that it can only store information while the computer is on. When the power is turned off, all the information is lost. The BUS is an electrical pathway inside the computer used to shuttle information between the RAM and the processor. The BUS is also where any additional pieces of hardware send messages to and from the processor. A few of these optional pieces include the monitor, keyboard, disk drive, and modem. The monitor is made up of a video card and a RGB (red green blue) gun.

Video cards are thin integrated circuit cards plugged into the computer. The video card interprets signals sent by the processor and directs the RGB gun to display them on the screen. Different types of video cards can draw different resolution pictures. The most common video cards in use today are the VGA (Video Graphics Array) and SVGA (Super VGA) cards.

The RGB gun prints the instructions on screen by using varying combinations of red, green, and blue. Each monitor also has a redraw rate, measured in hertz. The redraw rate is a measure of how many times per second the screen is re-displayed. The higher the number, the less flickering there is.

Common redraw rates range from 70 to 100 hertz. The keyboard is actually a large electrical field that can be interrupted by pressing a key. A change in signal is then sent to the processor when a key is pushed instructing the computer to take the corresponding action. A disk drive is used for long term storage on a computer. The three main types of disk drives are floppy, hard, and CD-ROM.

Floppy disks encode data using magnetics and can hold 1.44 megabytes and can be written on multiple times. Hard disks are the large disks installed inside the computer. An average storage size is 500 megabytes to 3000 megabytes. CD-ROMs (Compact Disk Read Only Memory) can hold around 650 megabytes, or 300,000 pages of written text.

They can hold 400 times the amount of a floppy disk, but cannot have data saved on them. They are also slower than hard drives, transferring data at a base rate of 150,000 bytes per second, whereas hard drives transfer data at several million bytes per second. The various speeds of CD-ROMs indicate how many times faster they can transfer data than the above rate. For example, a quad-speed CD-ROM can transfer data at about 600,000 bytes per second. The modem (modulator demodulator) is a device that sends and receives signals from remote computers over the phone line. Its speed is judged in bits per second or bps.

This is often confusing, as most information on a computer is measured in bytes. Most modem speeds range between 14.4 and 28.8 kilobits per second. A kilobit is approximately 1,000 bits. The set of instructions used to direct a computer is called a program.

Programs are written in various programming languages, combinations of math and near English keywords. Several common programming languages include BASIC, C, and COBOL. After a program is written, it must be compiled, or translated into a format the computer can understand. Even after all this, a master program is still required to interface between the compiled program and the processor. These interfacing programs are called operating systems. Windows 95, MS-DOS, and UNIX are all examples of operating systems.

Although a computer may seem almost intelligent at first glance, looking at the processor, hardware, and software reveals that a computer is nothing more than a series of linked switches.