Directions:
First open Microsoft Word.  Type your name and connections number at the top left.  Read the following article then answer the questions and in your own words.  Bold and underline your answers.  (Do not copy the text for your answer).  You must put the answers in your own words.  However, you may copy and paste the questions from this page into your Word document.  When finished, add the following graphics to your document in the correct areas on your document:

Hardware and Software

    Computers are made up of hardware and software.  Hardware is the tangible, physical equipment that can be seen and touched.  Examples of hardware are things such as the keyboard, printer, monitor, and computer chips.

    Software is the intangible instructions that tell the computer what to do.  Software are things such as PowerPoint, Windows XP, Sim City 3000, or Oregon Trail.  People who write software (instructions that tell the computer what to do) are called programmers.

    Programmers write instructions, or programs, to the computer so that it is able to execute a task or operate properly.  A program can be defined as a series of detailed step-by-step instructions that tell the computer precisely what actions to perform.

1.  a. What is hardware? _____________________________
     b. What is software?  _____________________________________________

2.  a.  What is a program?  ___________________________________________
     b.  Who writes programs?  ________________________________________

    Many people believe that computers can do just about anything and that their level of sophistication requires a genius to program and run them.  In reality, computers are very simple devices that can perform only four basic functions.  A computer can (1) store data and programs, (2) function unattended due to its ability to interpret and follow instructions it is provided, (3) do arithmetic calculations, and (4) perform logical comparisons.  What makes the computer such a powerful device, given only these four basic functions, is its tremendous speed, its accuracy, and its ability to store vast volumes of data.

3.  What three things make the computer such a powerful tool?  ________________
4.  Name 2 basic functions of the computer and give an example of the function. ____________

Memory - Chips (internal) - CD (external)

    The computer must be given instructions, in the form of software, which tell it exactly what to do.  The instructions that the computer follows are stored in locations known as memory.  For simplicity purposes think of memory in two categories:
(1) The computer's Internal memory  (ex. microchips)
(2) The computer's External memory  (ex. diskettes & hard drives)

    The computer's Internal memory which is composed of computer chips is divided into two types:  RAM (random-access memory) and ROM (read-only memory).  RAM's primary purpose is to temporarily store programs given to it by a programmer or operator of the computer.  This type of memory is temporary because it is erased when the computer is turned off (powered down).  In other words, all the information in RAM is erased when the computer is turned off.  It is called random access because  the processor can jump directly form one location to another in random order as the program is needed.  RAM holds programs such as  Microsoft Office Xp, MicroType Multimedia, Internet Explorer or whatever program the computer is running.

    ROM's primary purpose is to store important instructions that the computer will reuse over and over such as what to do when the computer is turned on and how to control specific requests made by the computer.  ROM is permanent memory that can not be changed or erased.  This is why it is called Read-Only Memory.

5.  ROM stands for: ______________________________
     and RAM stands for: ___________________________
6.  What is the purpose of the ROM and RAM memory?
    ____________________________________________
7. What is the difference between ROM and RAM? ___________________________________________
___________________________________________

Input and Output devices

    A hardware device which enables the computer to accept data is called an input device.  The most common example of an input device is a keyboard.  Other commonly known input devices include a mouse, bar-code scanner, light pen, touch display screen, and speech recognition device.

    A hardware device which reports the information in a form we can understand is called an output device.  The two most common forms of output devices are monitor, and printer.  Other examples include sound or music speakers, and robots.
Questions

8.  What is the function of an input device?  ______________________________
     Give an Example: ________________
9.  What is the function of an output device?   ______________________________
     Give an Example: ________________

Processors
    All computers do processing by following a series of instructions in a software program.  The computer chip that receives and carries out these instructions is called the processor.  All computer systems, regardless of size or manufacturer, have processors (also referred to as central processing units or CPUs).

    The processor performs many different functions.  It receives and temporarily stores instructions as well as the data to be processed.  It moves and changes stored data.  It does arithmetic calculations.  It makes decisions of logic, such as determining if two numbers are equal.  It directs the action of the input and output devices.   The CPU is often referred to as the brains of the computer system.

10.  Name one function of the processor?  ______________________________
11.  What is the CPU often referred to as?  ______________________

External Storage

    Nearly all general-purpose computers include the ability to connect to additional storage devices that hold data outside the memory of the computer.  These additional storage devices are known as external storage.  External  storage devices are on-line to the computer; that is, they are connected directly to the computer.  They are, therefore, under the control of the processor and can be used at all times.  The most common form of external storage is a thumb drive (aka... USB flash drive).    Other forms of external storage include hard drives and CD/DVD (recordable) drives.

A flash drive can hold between 256 MB (megabytes) to 8 GB (gigabytes) of memory where one CD can store 700 MB (megabyte).  A single layer DVD can hold 4.7 GB (gigabytes of memory).  Hard drives can hold even more.  Most hard drives hold between 60 GB (gigabytes) to 1000 GB (or 1 tarabyte).

12.  What is an external storage device?  _______________________________
13.  What are 2 examples of external storage __________________________
14.  Why is it important to have an external storage device _______________________

The Computer's World

    To help you understand how the computer works, imagine that each character is represented inside the computer by a series of electronic switches.  In many ways, these electronic switches can be compared to the light switches in our home.  A light switch can be in only one of two states: on or off.  The circuits inside the computer can be thought of in much the same way as the light switches.  The electronic switches can be either on or off.  Since on and off represent only two conditions the computer understands, it is impossible for the computer to communicate the way we do with words.  All it knows is an electrical state of on and off.  Isn't that incredible considering what a computer can do?  But you ask, we have lots more numbers than 0 and 1 and many more than just 2 words.  You see, numbers and words are instead converted into binary numbers.  Binary means "consisting of two things", so a binary number is made by using only two digits, 0 and 1.  The number 0 represents "off" to the computer and the number 1 represents "on" to the computer.  Much of the world's number system is based on the 10 system but the computer's system is based on the Binary system.  Therefore the binary number system is the only coding system the computer actually understands.

15.  How many states can a light switch be in? ____________
16.  Electronic switches can be _____ or _____
17.  The "on" and "off" switch represent what numbers to the computer? _______________
 

    Imagine eight on/off switches grouped inside the computer.  Each switch (0 or 1) is called a bit.  The on switch is like a light being turned in the on position.  The computer represents it as the number 1.  The off position is represented by the computer with the number 0 (zero).  It takes eight switches (Bits) to store one character (letter, symbol, or space).  As shown below 01010011 is the way the computer understands the letter S.   It sure does take a lot of switches to type one letter on the computer.  Luckily for the computer that it operates at the speed of light which is 186,282.397 miles per second

     

0 1  0  1 0 0 1 1

=     the letter:   S

A combination of eight switches (bits)  is called a byte in computer terminology.  The computer groups eight bits together to form a byte because it has proven to be a good combination for the computer to handle.

18.  Watch the Brainpop then explain the binary system in more or two sentences? _________________

    By using eight bits to turn various switches on and off, there are 256 different combinations possible.  In the binary number system, there can be as many 0's and 1's as needed within the eight switches to represent a particular number.  Each 0 can be thought of as representing a switch that is turned off, while each 1 represents a switch that is turned on.

    Each time a key on a keyboard is struck, a binary number is generated in the computer via electronic signaling (see example above).  Inside the computer, the binary number is stored in a memory chip.  All data inside the computer is represented by the use of binary numbers.

19.  Explain what a bit and byte are.  _____________
20.  How many different combinations are available with an 8 bit system?  ______________________________________

    We have now learned that the processor and memory (both ROM and RAM) are made up of electronic circuits that represent information by turning switches off and on.  And we learned that eight switches or bits make up a byte and each byte can store one character of data.

Computer memory is measured in bytes.  A single byte is made up of a series of 1's and 0's normally traveling in pairs of eight.  These eight 0's and 1's are the way the computer communicates and stores information.  With each keystroke or character a byte of memory is used.

Directions:  Draw this table into your document.

If we were to key in the name Ernest Grover, it would take thirteen (13) bytes to store the name in RAM.  The space between the first and last name would require one byte, and the  (12) twelve letters of the name would require twelve bytes.
 

    E     r       n        e      s       t                G       r       o       v      e        r    =13 bytes-used
 

    Computer manufacturers express the capacity of memory in terms of the letter K. K is short for Kilobyte, which means 1024 bytes of computer memory.  Some of the first personal computers had 64K of memory (RAM).  This meant that the computer had approximately 64,000 bytes of memory and had the capacity to store up to 64,000 characters during processing in RAM.  Many disks, hard drives, and CDs can store hundreds, thousands, and even millions more memory than the RAM chips in a computer.  For example an average floppy disk can hold 1.4MB or  1440K or 1,440,000 million bytes.  An average CD-R holds up to 700MB of information (or 700,000,000 million bytes) and an average hard drive can hold 60GB which is 60,000,000,000 billion bytes and   If a MB (megabyte) is 1 million bytes then 1 GB (gigabyte) is a billion bytes and some hard drives are now even 1 terabyte which is 1 trillion bytes or 1000 billion bytes of memory.

21.  What holds more memory a CD or the average Hard Drive? ______

22.  Explain what makes up a byte of memory? __________

The Three Basic Generations of Computers:

There are 3 basic generations of computer.  The first began in 1946-1958 (The Vacuum Tube Years).  These computers were huge, slow, expensive, and often undependable.  In 1946 the ENIAC was built.  The ENIAC used 18,000 thousand vacuum tubes, which took up a lot of space and gave off a great deal of heat just like light bulbs do. 

The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners.  However even with these huge coolers, vacuum tubes still overheated regularly.  It was time for something new.

The Second Generation:  1959-1964 (The Era of the Transistor) did not last as long as the vacuum tube computer lasted, but it was no less important in the advancement of computer technology.

The transistor which functioned much like a vacuum tube in that it can be used to relay and switch electronic signals was obviously different in many ways.  The transistor was faster, more reliable, much smaller, and much cheaper to build than a vacuum tube.  They also gave off virtually no heat.  One transistor replaced the equivalent of 40 vacuum tubes.  

The Third Generation:  1965-current (Transistors on a chip).  Transistors were a tremendous breakthrough in advancing the computer.  However no one could predict that thousands even now millions of transistors (circuits) could be compacted in such a small space of silicon. Since the invention of integrated circuits, the number of transistors that can be placed on a single silicon chip has doubled every two years, shrinking both the size and cost of computers even further and further enhancing its power.

These third generation computers can carry out instructions in billionths of a second.  The size of these machines dropped to the size of a watch. 

Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers.

23.  Explain in order the three generations of computers.____________________

24.  What were the advantages of the transistor over the vacuum tube? _______________________

25.  What are the advantages of putting more and more transistors on a chip? ___________________

Review how a computer works using BrainPop.com

Finish the worksheet  on the following pages.

    As you know, computers usually deals with numbers in groups of eight bits called a byte.  And these bytes make up characters, letters, numbers, and symbols on the keyboard.  What you might not have known it that programmers, the people who write the  instructions for computers use to have to send the instructions to the computer in binary code (base two).  Then they had to change back the computer's response into base ten numbers so that everyone could read them easily.

    To change 00010110 into a base ten numbers, first fill in a tally box to show the number.

Ex.   00010110  ______22_______

Base 2 place values:

 What does ours look like?

107	106	105	104	103	102	101	100
10,000,000	1,000,000	100,000	10,000	1,000	100	10	1
						2	2

Then, add up the numbers on the top of each box which is filled in with a 1.       For example   16 + 4 + 2 = 22  therefore 22= 00010110

Now find the base ten numbers for each of these base two numbers.

1.  00000110   _____________

128	64	32	16	8	4	2	1

2.  00000011   _____________

128	64	32	16	8	4	2	1

3.  01001101  ____________

128	64	32	16	8	4	2	1

4.  01101000   ____________

128	64	32	16	8	4	2	1

5.  01010111   _____________

128	64	32	16	8	4	2	1

6.  11111111  _______________

128	64	32	16	8	4	2	1

Directions:  Now convert base 10 number to base 2
 

7.  173    _____________

128	64	32	16	8	4	2	1

8.  59    _____________

128	64	32	16	8	4	2	1

9.  242    _____________

128	64	32	16	8	4	2	1

10.  199    _____________

128	64	32	16	8	4	2	1

Bonus Activity: 5 pts

Today's programmers give instructions to computers in what are called high level languages.  These languages use words the programmer can understand.  The computer changes these words into the binary machine language it can use.

Programmers used to have to do the changes themselves.  Here is a copy of a binary letter code.  use it to solve the mystery.

The programmer was missing.  One minute she was seen working at her computer.  The next minute she was gone.  She was not in the office.  Where could she have gone at ten o'clock in the morning?  The only clue was a message she left on her computer.  Decode it to find out where the programmer went.

last updated: Thursday, January 10, 2008