Thurs 1/17 Week 1

Thurs 1/17 Week 1

Chapter 1

Objectives

History of computers

Parts of a computer

Introduction to Software Development Methods

1. The History of computers

· Table 1.1 (pg. 5)

· Hardware components of a computer Fig 1.3 pg 10

· main memory

· secondary memory: storage devices such as

· central processing unit (CPU)

· input devices:

· output devices

2. Main memory

· RAM, Random access memory

· individual memory cells which

· RAM measured in megabytes which is approximately one million cells

· Cells may contain

· each bytes is made up

· a bit is a binary digit and can contain a 1 or a 0

· Figure 1.4

3. Secondary memory

· hold data in a similar manner to RAM

· some are rewritable

· some are only writable once

· some are read-only

4. CPU

· two roles:

· follows instructions provided in a program which has been loaded into main memory

· retrieves the instruction sequence

· interprets ( ) the instructions and decides what should be done, then retrieves any necessary data to carry out that instruction

· performs the actual manipulation of the data

· stores the result in memory for later use

5. Problem solving and Programming

· Simple problem solving with computers is like turning a word problem into an algebraic equation. Simply translating from English to a computer programming language

· most problems in computing are not this simple, but there are some basic problem-solving skills that can be learned

6 . Skills

· Asking the right questions

· Analyzing the problem

· Determining any constraints

· Applying knowledge of the problem environment and the formulas or equations that characterize it.

· Verifying the programs accuracy by developing and carrying out a test plan

7. the Software development Method

· Problem Specification:

· Analysis

· Design:

· Test Plan:

· Implementation or coding

· .

· Testing:

· Example of changing a tire page 21

8. Writing, Compiling, and Running a program

· write the program in an editor

· save the file with a unique name, ending in .adb (Ada Body File)

· start the compiler which will verify your program’s correctness (gcompile filename.adb)

· There may be problems reported by the compiler, if so reedit your file, save it and try again

· Once the program compiles, link your program. (glink) This coordinates your program with any other libraries you may have used (e.g. Ada.Text_IO for text input and output to the screen)

· Then run the program and start your test program. (gexecute)

· If your program fails your test plan or does not run as you expected, reedit your program file and compile, link and execute it again