Cmpe 150- 03

cottonseedfearnotElectronics - Devices

Nov 7, 2013 (3 years and 9 months ago)

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Cmpe 150
-

03

Summer 2001

SOFTWARE PACKAGES


1960s:


mainframe nuclear physics applications


mainframe machine control programs


mainframe accounting applications


1970s:


mainframe database managers


PC accounting applications


PC word processing


PC telecommunications


PC spreadsheets


1980s:


PC database managers

SOFTWARE PACKAGES


SOFTWARE PACKAGE TECHNOLOGY


User friendly package


Batch package


Interactive package


Menu driven


Pull down menu


Icons


Tutorial disk

SOFTWARE PACKAGES


OPERATING SYSTEM:


Provides an interface between the user and the computer


Schedules an efficient use of the CPU and eliminates the need for
human intervention


Manages data and files making them available as needed and
provides security to multiple users


Executes other computer programs


Manages peripheral devices such as printers, disk drives, and tape
drives.

SOFTWARE PACKAGES


MAINFRAME OPERATING SYSTEMS:


The OS for a mainframe computer must be able to run multiple
jobs concurrently.


In a
time
-
sharing system
, a computer gives each active terminal a
fraction of a second of CPU time. During this time a portion of a
program entered at the terminal is executed.


In a
batch mode

en entire job is entered at one time from a disk
drive. Each job is assigned a priority and placed in a queue to be
executed.


Multiple batch entry sites are called
remote job entry

sites.

SOFTWARE PACKAGES


HOW DOES THE OS DO IT?


Supervisor Program
: remains in internal memory at all times and
manages the loading of other parts of the OS into the memory as
needed. It also supervises the loading of application programs into
the internal memory.


Compiler
: is the program translator


Buffer
: is a section of memory separate from the internal memory
unit which acts as an intermediary storage area for input and
output. Therefore CPU is not slowed down by the input/ output
process because of the buffer.

SOFTWARE PACKAGES


PC Operating Systems:


The operating system controls the hardware


It interprets the user ’s commands;
command interpreter

determines what keystrokes mean and sends a message to the
appropriate utility or application program to carry out the
command.


The operating system maintains a file system on secondary storage.


DOS file system has a unique name for each file, which is
supplied by the user and is used for future retrievals


The list of the files on a disk is known as DISK
DIRECTORY


SOFTWARE PACKAGES


EXAMPLES OF MS
-
DOS COMMANDS:


COPY: Copies one or more files to a new disk or location

COPY A:TEST B:TEST



DIR: Displays a directory of the user ’s files

DIR A:



FORMAT: Initialises a disk

FORMAT B: