Tugas PK BAB 4

PENGENALAN KOMPUTER BAB 4

++Linus Torvalds and the Software
Nobody Owns

ü  Linus Torvalds

Ø  Best known as the Linux creator

q  The Linux operating system is the best-known example of open source software.

q  Today Linux powers Web servers, film and animation workstations, scientific supercomputers, and a handful of handhelds.

ü  The three major categories of software:

ü  OS vs. Application software

ü  Food for Thought

ü  A Fast, Stupid Machine

ü  The Language of Computers

ü  Machine Language: numeric codes that represent data

-High-level language: falls between machine language and natural human language

-Compilers translate high-level language into machine language.

-Natural Languages: resemble languages spoken by human.

++SOFTWARE APLIKASI

ü  Consumer Applications

Ø  Many software companies have replaced their printed documentation with:

q  Tutorials

q  Reference materials

q  Help files

q  On-line help

Ø  Upgrading: Users can upgrade a program to the new version by paying an upgrade fee to the software manufacturer.

q  Newer releases often have additional features and fewer bugs.

Ø  Compatibility

Ø  Disclaimers

• Licensing: Commercial software is copyrighted so it can’t be legally duplicated for distribution to others.

§  Software license

§  Volume licenses

§  Distribution: Software is distributed via:

                                                                                                               i.      Direct sale

                                                                                                             ii.      Retail stores

                                                                                                            iii.      Mail-order catalogs

                                                                                                           iv.      Web sites

                                                                                                             v.      Not all software is copyrighted.

                                             -Public domain software

                                            -  Shareware

++SYSTEM SOFTWARE

ü  Operating system functions:

Ø  Supports multitasking

Ø  Manages virtual memory

Ø  Maintains file system

Ø  Responsible for authentication and authorization

Utility Programs and Device Drivers

ü  Utility programs

Ø  Serve as tools for doing system maintenance and repairs that aren’t automatically handled by the operating system

Ø  Make it easier for users to:

q  Copy files between storage devices

q  Repair damaged data files

q  Translate files so that different programs can read them

q  Guard against viruses and other potentially harmful programs (as described in the chapter on computer security and risks)

q  Compress files so they take up less disk space

q  Perform other important, if unexciting, tasks