LA283 Section 2
                         Computer Fundamentals II
                              January 16, 1996

Communications: refers to the transmission of data and information over a 
	communications channel.

Digital signal: produced by the computer in the form of individual 
	electrical pulses; 0's and 1's.

Analog signal: continuous electrical waves ; data, information, and voice
	are all transmitted over phone lines via analog signals.

Modem: a peripheral piece of hardware that converts digital signals to
       analog signals, and analog signals to digital signals 
     		MOdulate: convert digital to analog
     		DEModulate: convert analog to digital
Modems transmit data and information at rates measured in bits per seconds (BPS).

Communications channel: path that data and information follow as they
	are transmitted from the sending equipment to the receiving equipment 
	in a communications system

Transmission media: channels are made up of one or more transmission media
Examples:  twisted pair wire
           coaxial cable
           fiber optics
           microwave transmission
           satellite transmission

Communications network: collection of computers and other equipment using 
	communications channels to share hardware, software, data, and information

     Hardware Resource Sharing

     Information Resource Sharing
          File server: server sends an entire file at a time ; requesting 
                       microcomputer performs all processing

          Client-server: processing tasks are divided between the server 
                       computer and the client computer (decreases network traffic 
                       but requires a more powerful server)


Choosing and Buying a Computer:

 Software needs:
     operating system and environment (Mac v Windows v DOS v Windows95)
     software availability
     word processing
     spreadsheet
     data base management
     graphics
     communications
     multimedia
     etc, etc, etc, etc, etc

 Hardware needs:
     sufficient RAM and fixed disk space
     monitor
     drives; example, CD-ROM drive 2x, 4x, 6x
     modem v fax/modem; internal v external modem
     printer; impact v non impact
     tape back-up
     uninterruptable power supply (UPS)

 Vendors:
     Penn State's Microcomputer Order Center (The MOC)
     Willard Building; 865-2100
     mail order vendors 
     local computer stores

 Considerations:
     long-run growth path
     leaving Penn State
     maintenance and repairs
     storage
     cost of accessories