1. Materials prepared by Dhimas Ruswanto, BMm
Skill Area 310 – Part B
Materials prepared by Dhimas Ruswanto, BMm

2. Lecture Overview CPU Main Memory User Interface
Systems Software Concepts
Utility Programs

3. Computer System Processing (CPU/Memory) Input Devices Output Devices
Storage Devices

4. CPU Also called CPU, processor or microprocessor
“Brains” of the computer
Performs all computer operations

5. Main Memory Where all the input data and results stored
Random Access Memory (RAM)
Read Only Memory (ROM)

6. RAM RAM is volatile = data are lost when computer is turned off
Read current info and also write new info
Very important in determining capabilities of the computer system
Stores work when they are in use.
Word Document
Spreadsheet
Power Point

7. ROM
ROM is non-volatile = permanent and are not affected where computer is turned lost
Can read info Stored in ROM
Can not write new info into ROM
Used for “internal workings” of computer
Boot Software

8. User Interface
A function of the operating system that allows individuals to access and command the computer
Command-based User Interface
A particular user interface that requires text commands be given to the computer to perform basic activities
E.g., unix, DOS
Graphical User Interface (GUI)
A user interface that uses pictures (icons) and menus displayed on the screen to send commands to the computer system
Input Devices -> keyboard, mouse, monitor, touch-screen
Features of GUI -> Windows, Icons, Menus, Pointer

9. Systems Software Concepts
Hardware Independences
Memory Management
Processing Tasks
Networking Capability
Access to System Resources and Security
File Management

10. Systems Software Concepts
Hardware independence
Operating system (OS) provides hardware independence for application software
Application software interfaces (API) with the operating system which interfaces with the hardware
Memory management
Control how memory is accessed and maximize available memory and storage

11. API Application Programming Interface (API)
A language and message format used by an application program to communicate with the operating system or some other control program such as a database management system (DBMS) or communications protocol
Application Program Interface Links Application Software to the Operating System

12. Systems Software Concepts
Processing Tasks
Multitasking / Multiprogramming:
More than one program in RAM at the same time
Allows more than one active user program to be stored in main memory simultaneously
Fairly sophisticated
All the jobs that enter the system are kept in the job pool. This pool consists of all processes residing on mass storage awaiting allocation of main memory.
If there is not enough room, then the system must choose among the jobs.
A time-sharing system is a multiprogramming system.

13. Processing Tasks (cont’d)
Time-Sharing
Sharing of a computing resources among many users by means of multiprogramming
Allowing a large number of users to interact concurrently with a single computer
Dramatically lowered the cost of providing computing capability
Made possible for individuals and organizations to use a computer without owning one
Promoted the interactive use of computers and the development of new interactive applications

14. Systems Software Concepts
Networking Capability
Features and capabilities of the OS that aid users in connecting to a computer network
Allow connected computers to:
Communicate
Share resources
Divide work

15. Systems Software Concepts
Access to system resources and security
Protection against unauthorized access
Logins and passwords
File management
Ensures that files in secondary storage are available when needed and that they are protected from access by unauthorized users

16. Utility Programs
Help to perform maintenance or correct problems with a computer system.
Designed to limited range of tasks
E.g. :
Hardware utilities,
Virus-detection
Recovery utilities
File-compression utilities,
Spam and pop-up blocker utilities

17. Summary CPU is a ‘brain’ of a computer Main Memory: User Interface
RAM (volatile) & ROM (non-volatile)
User Interface
Command-based User Interface
Graphical User Interface
Systems Software Concept:
Hardware Independences
Memory Management
Processing Tasks
Networking Capability
Access to System Resources and Security
File Management