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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
• 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.
• 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
memory 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
• Humans
– Fast
– Slow
– Accurate
– Innacurate
– Dumb
– 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 humans can
communicate instructions to be
executed by a computer.
The Evolution of
Programming Languages
1. Machine Language
– Consists of 1s and 0s
– The only language computers
understand
2. Assembly language
– Substitutes mnemonics or macros for
numeric code
3. Third Generation (Procedure Oriented)
4. Fourth Generation (Event based)
5. 5GL (Incorporates AI)
Language Translation
• Source Code
• Object Code
• Compiler
• Interpreter
Software Crisis
• Excess Demand
• Development Backlog
• Hidden Backlog
• Can 4GL’s Help
• Why the Hesitation
• No Standards
• Erodes Organizational Power
Software
Information Systems and Management