Software

Information Systems and Management

Software

Computer programs:

A sequence of instructions for the computer.

Systems Software

The set of programs designed to coordinate the activities and functions of the hardware and various programs throughout the computer system.

Applications Software

Programs that help users solve their particular computer problems

Systems Software

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Operating Systems (OS)

A set of computer programs that controls the computer hardware and acts as an interface with application programs •

User Interface

The element of the OS that allows individuals to access and command the computer system.

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Graphical User Interface (GUI)

Uses icon and menus to send commands

Memory Management

• Controls how memory is accessed

• Virtual Memory

– Allocate space on the hard drive to supplement primary memory capacity

• Paging

– Process of swapping programs or parts of programs between primary meory and the hard drive

Capabilities

• Multitasking – More than one task resident in PC primary memory • Time-Sharing – More than one person can use the computer at the same time • Scalability – The ability of the computer to handle an increasing number of concurrent users

Computers and Humans

• Computers – Fast – Accurate – dumb • Humans – Slow – Innacurate – Smart

More Capability

• Network Capability – Aids users in connecting to a network • Access to System Resources – User identification and passwords • File Management – Ensure files in secondary storage are available when needed – Ensures files are protected from unauthorized access

Even More Capability

• Virus detection • File compression • Spam and pop-up blockers • Middleware: software that allows different systems to communicate and transfer data back and forth

Application Software

Proprietary Software

A one-of-a-kind program for a specific application, usually developed and owned by a single company

Off-the-Shelf Software

Existing software program that is purchased • Must meet 90% of functional requirements • Sports Jacket

Personal Application Software

• Software Suite – A collection of application programs packaged in a bundle • Workgroup Application Software – Software that supports teamwork even in multiple locations • Enterprise Application Software – ERP

Programming Languages

Sets of keywords, symbols, and a system of rules for constructing statements by which human can communicate instructions to be executed by a computer.

The Evolution of Programming Languages 1. Machine Language

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Consists of 1s and 0s The only language computers understand 2. Assembly language

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Substitutes mnemonics or macros for numeric code 3. Third Generation (Procedure Oriented) 4. Fourth Generation (Event based) 5. 5GL (Incorporates AI)

Language Translation

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Source Code

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Object Code

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Compiler

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Interpreter

Software Crisis

• Excess Demand • Development Backlog • Hidden Backlog • Can 4GL’s Help • Why the Hesitation • No Standards • Erodes Organizational Power