CS 3 - Kurtz  Santa Monica College 



Batch Processing  Circa 1960s 
Each batch of work is scheduled in advance and processed in turn 
Punched cards
Time Sharing  Circa 1970s 
Many users on-line simultaneously 
Terminals connected to a host computer 
Command Line Interface (CLI)
Personal Computing  Circa 1980s 
Desktop Computers 
One computer per user 
Graphic User Interface (GUI) uses icons to represent programs, folders, and files
Networked & Mobile Computing  Circa 1990s 
Dozens (or thousands) of individual computers networked 
The Internet 
Laptop and Palmtop computers 
Wireless connections
Current Decade Circa 2000s
Computing and telecommunications overlapping
Reliance on networking technologies, especially the Internet
Internet access widely available
Distributed server functions
Imbedded Microcomputers  Smallest and least powerful type of computer 
Imbedded in another product (toys, cars, avionics) 
Mobile Comuters &
Mobile Devices
Notebook computers
Tablet PCs
Handheld computers
Smart Phones
PDAs (Personal Digital Assistants
Personal Computers Desktop Computers
Midrange Servers  Used to support many users at once (office environment) or for special applications (assembly lines, lab data collection) 
Faster and more powerful than micros
Mainframes  Large, fast, and expensive 
Hundreds or thousands of simultaneous users 
Used for applications requiring extensive calculations 
Used for applications requiring large volumes of data 
Banks, insurance companies, large corporations, governments
Supercomputers  Very fast and expensive
Analysis of scientific and engineering data
Computer Hardware  Input Device(s) 
Output Device(s) 
Central Processing Unit 
Storage Device(s)
Application Software  Practical programs for work or games 
Office applications: word processing, spreadsheet, database, presentation, scheduling, desktop publishing
System Software  Operating Systems: Windows, DOS, Mac OS, UNIX, Netware, and others 
Utilities: Printer Drivers, Memory Manager, File Manager, Task Scheduler, Uninstaller, others.
Operating System Controls the computer 
Controls all devices connected to the computer 
Interfaces between you and the computer
Programming language Used to write system and application software
BASIC, FORTRAN, COBOL, C, C++, PERL, Java, Visual Basic, APL, PL/1, Pascal, Forthe, LISP, ALGOL, ALGOL 68, more
Four Computer Processes Input
Local Area Network LAN
Interconnection of computers that are geographically near
Used to share resources and information
Wide Area Network WAN
Similar to LAN, but geography is not a consideration
May interconnect LANs