PPT Slides by Dr. Craig Tyran & Kraig Pencil

Information Systems Software

MIS 320

Kraig Pencil

Summer 2013

A. Game Plan

• Application Software

• Systems Software – Operating System– Support Programs

• Compatibility issues

• Role of Microsoft

B. Application Software1. What is it?

– SW that performs a specific task for user

– Examples?

2. Categories– Personal application software

(a.k.a. personal productivity software)• e.g., MS Office

– Entertainment• e.g., games, music, etc.

– Business application software• e.g., payroll, inventory, DSS

C. Systems Software1. Definition

– Software that manages and supports the computer system

2. Categories– Operating system

– Support programs

3. Operating system (OS)

– Supervises the overall operation of computer

– Serves as a critical link in computer operations … a bridge/interpreter

– hardware

(and the user*)– application software– other computers

* Of course, the user interacts with the operating systemthrough the hardware: mouse, keyboard, screen, etc.

Operating Operating SystemSystem

C. Systems Software

Application Software

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D. Operating System: Functions1. Processor Management

– A computer often needs to juggle several processes at one time (i.e., multitasking)

• Examples???

– A good OS handles multitasking without user even knowing about the “juggling”

– If too many processes at once … “Thrashing” occurs as CPU swaps back and forth among processes

– Some CPU’s contain 2 two or more processors that run simultaneously.

D. Operating System: Functions2. Memory

management– Processes

require “memory space” (i.e., “primary storage”)

– OS Allocates memory across processes

D. OS: Functions (cont.)3. Storage management

– Allows users to save, delete, access, & organize files stored in long-term “secondary storage”

– OS Keeps track of physical location and characteristics of files

4. Device management– “Devices” include

• Keyboard, mouse, printer, DVD player, etc.

D. OS: Functions (cont.)4. Device management (cont.)

– OS needs to interact with the devices (e.g. printers) of many makes and models … each with their own design, abilities and “languages”

• How to translate signals between OS and devices?

OS Devices

– Software “drivers” are used to translate the interactions• This is why you often need to load the “driver” SW when you add a

new device (mouse, printer, etc.) to your PC system

D. OS: Functions (cont.)

5. User interface– This is what the

user sees– Recall earlier figure

of OS linkages

How easy is it to … ?

– Create, store, and manage files?

– Start software applications?

– Manage input or output devices?

• Old “command-line” systems used keyboards only – and only letters and numbers on screen.

• Today we prefer a Graphical User interface, a GUI, with a mouse and point and click.

• And in the future? … http://www.youtube.com/watch?v=oO0yzTW62xQ

6. Application Program Interface (API)– This is what the application software sees

– Recall earlier figure of OS linkages

– The API is a set of rules and specifications that allows application software to easily interact with various CPU and hardware designs

– Application developers use the API rules when they write their applications

D. OS: Functions (cont.)

Application SoftwareOperating

SystemAPI

E. Support Programs

1. Examples include– Anti-virus software

• Scan/eliminate viruses!!!

– Connectivity software• e.g., Use to connect to the Internet

– Housekeeping software• Monitor and optimize performance• Backup and recover data• Defragment files • … and so on.

F. Popular OS1. OS for microcomputers

– Examples?

2. OS and other hardware platforms– Unix: Micros, workstations, mainframes– Linux: Micros (see above), workstations, mainframes,

supercomputers• “Open source” software• Can offer lower-cost, solid performance• Businesses have shown interest (e.g., servers, transaction

systems)

– MVS (Multiple Virtual Storage): Mainframe computers made by IBM

G. OS and Compatibility Issues1. OS is typically designed for a specific HW “platform”

(i.e. “CPU” model)– Examples of HW “platforms”

• Intel-based PC

• Apple (PowerPC and Intel)

• IBM mainframe

2. Many organizations have multiple types of HW– OS are designed to work with a given HW (or vice versa)

Multiple types of OS may exist within an organization

3. Application SW is typically designed for a specific OS– Example (see following slide)

G. OS and Compatibility Issues1. OS is typically designed for a specific HW “platform”

(i.e. “CPU” model)– Examples of HW “platforms”

• Intel-based PC

• Apple (PowerPC and Intel)

• IBM mainframe

2. Many organizations have multiple types of HW– OS are designed to work with a given HW (or vice versa)

Multiple types of OS may exist within an organization

3. Application SW is typically designed for a specific OS

– Example (see following slide)Application

Software

Operating System

API

Software Downloads and OS Options

Different softwarefor different OS

G. OS and Compatibility Issues (cont.)

4. If an organization has mulitple computer HW platforms and/or multiple OSs ….

Potential compatibility problems

5. Examples of potential problems– Application SW that works on one

computer may not work on another computer

Can be difficult to standardize SW applications

G. OS and Compatibility Issues (cont.)5. Examples of potential problems (cont.)

– Different types of computer systems may not be compatible

e.g., IS For Finance Dept vs. Marketing Dept Need to “patch together”

different HW and SW for communication

– IS support staff needs to learn different “languages”

– Lots of headaches for all ….

1. In past years, Microsoft (MS) has had a solid position with regard to PC operating systems

2. Based on what we have discussed regarding the general role of OS software, how has MS’s position regarding OS provided MS with a source of power in the field of PC computing?

– With regard to application software market? – With regard to hardware market?

H. Role of Microsoft