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Introduction

Welcome to TEJ2O - Introduction to Computer Engineering. Computer Engineering is a discipline that integrates several fields of electrical engineering and computer science required to develop computer systems. Computer engineers usually have training in electronic engineering, software design, and hardware-software integration instead of only software engineering or electronic engineering. Computer engineers are involved in many hardware and software aspects of computing, from the design of individual microprocessors, personal computers, and supercomputers, to circuit design. This field of engineering not only focuses on how computer systems themselves work, but also how they integrate into the larger picture. 

Computer Lab Rules

You are responsible for knowing these rules. The over-riding principle is that computers are to be used strictly for educational purposes only.

1. You are not allowed to eat or drink (water may be left at desk) near the computers

2. Do not share your passwords with others. Do not let anyone else use your account!

3. You are not allowed to play games, apart from games that are part of your course work. No commercially prepared games can be brought into the lab or installed please.

4. You are not allowed to have streaming video. (too much bandwidth).

5. Do not bring bags and coats into the lab.

6. Do not alter things like the desktop/system files without permission

Number Systems

A numeral system (or system of numeration) is a writing system for expressing numbers, that is a mathematical notation for representing numbers of a given set, using graphemes or symbols in a consistent manner. It can be seen as the context that allows the symbols "11" to be interpreted as the binary symbol for three, the decimal symbol for eleven, or a symbol for other numbers in different bases. (source)

At first, it would seem like using any number system other than decimal is complicated and unnecessary. However, since the job of electrical and software engineers is to work with digital circuits, engineers require number systems that can best transfer information between the human world and the digital circuit world and those forms are usually binary, octal, or hexadecimal. It turns out that the way in which a number is represented can make it easier for the engineer to perceive the meaning of the number as it applies to a digital circuit. In other words, the appropriate number system can actually make things less complicated.

• Consider the number 294. The steps below show how to convert this number to binary using repeated division by 2. The 'R' stands for the remainder of the division

Converting Binary to Decimal

To convert binary to decimal is relatively easy. All you have to do is list out the columns, then add up representative placeholders. Let's say for example we want to convert 101101(0b) to dec:

32 + 8 + 4 + 1 = 45

Converting Decimal to Hex

You can also use the dividing approach as with binary, but with alterations. Here are the steps:

Step 1: Divide the number by 16. Store the whole number for the next step. Take the decimal remainder (if there is one) and multiply by 16. Store it.

Step 2: Take the whole number from the last step and divide by 16 as per the last step. Repeat these 2 steps until the last whole number is 0. This will be the last step

Step 3: The final hexadecimal value will be the reverse order you stored (like in dec to bin conversions) 

EG Decimal number = 450(10)

Step 1: 450/16 gives 28.125, Store 28 for the next step. Multiply 16x0.125=2 so the remainder = 2

Step 2: 28/16 gives 1.75; Store 1 for the next step. Multiply 16x1.75 = 16, with a remainder of 12 = C

Step 3: 1/16 gives 0; 16x0 and remainder = 1

Step 4: 0/16 gives 0 and remainder = 0

Therefore, the hexadecimal value is 01C2(16)

EG Decimal number = 118(10)

Step 1: 118/16 gives 7.375, Store 7 for the next step. Multiply 16x0.375=6 so the remainder = 6

Step 2: 7/16 gives 0.4375; Store 0 for the next step. Multiply 16x.4375 = 7, remainder of 7

Step 3: 0/16 gives 0 and remainder = 0

Therefore, the hexadecimal value is 076(16)

Converting Hex to Decimal

Is exactly like converting binary to decimal, simply list out the columns and add the results.

Let's take the number 1D16

16's column  |  1's column

(1 x 16)           +   (13 x 1) = 2910

How about this one A6316

256's column | 16's column  |  1's column

(10x256)          +  (6x16)           +  (3x1) = 265910

Try this:

C0216 to base 10 (equals 3074 )

Converting Binary to Hex and Hex to Binary

This is the easiest type of conversion because we break the columns in hex down into 'octets' (also known as a byte).

CONVERSION QUIZ REVIEW

Be able to convert from

• dec to bin, bin to dec

• dec to hex, hex to dec

• hex to bin bin to hex

ASCII

ASCII (American Standard Code for Information Interchange) is the most common character encoding format for text data in computers and on the internet. In standard ASCII-encoded data, there are unique values for 128 alphabetic, numeric or special additional characters and control codes.

ASCII encoding is based on character encoding used for telegraph data. 

Characters in ASCII encoding include upper- and lowercase letters A through Z, numerals 0 through 9 and basic punctuation symbols. It also uses some non-printing control characters that were originally intended for use with teletype printing terminals when the system was developed in 1963

As far as we're concerned, ASCII characters may be represented in the following ways. Let's take the letter Z (capital):

    as pairs of hexadecimal digits  (eg 5A)

    as decimal numbers from 0 to 127; (eg 90) or

    as binary (101 1010)

This website can provide more details about ASCII