NCR PC4i Owner's Manual

Also see for PC4I: Technical reference Service manual Service manual

Contents

NCR PC4i Owner's Manual Manual pdf 24 page image

HISTORICAL DATAThe operating system provides communication abilities between youand your computer through prompts and commands. A prompt is adisplayed message or other signal by the operating system thatindicates you should make a decision or perform some action beforethe system can continue. Sometimes you are given a specific set ofchoices, such as Y/N (Yes/No). Other times the system completes aportion or all of a task and you enter one of the set of commandsrecognized by your operating system. These commands direct thesystem to perform tasks like:1. Begin the next program desired.2. Rename or delete a file.3. Display the directory (list of contents) of a disk.An example of an operating system is the NCR-DOS.Run-time Interpreter RoutinesA computer that executes directly from a source code needs arun-time interpreter. The run-time interpreter has routines whichperform specific sets of machine-language operations to accomplishthe purpose of each instruction. The GW-BASIC interpreter is anexample of a run-time interpreter.Utility ProgramsEvery computer needs utility programs to perform very commonfunctions, such as text editing of data or program source code,copying, comparing, or sorting data files, formatting of disks ordiskettes, etc. Utility programs can be called in by operating systemcommands, or they can be accessed like application programs.Program Development SoftwareA specific set of source code instructions, data description techniquesand conventions, and procedures used to create programs make up aprogramming language. Included also are control instructions todirect the program development software or run-time interpreter totranslate the source code into object code which is (after anynecessary linking and conversion) machine-understandable.The final code tells the computer what operations to perform and inwhat sequence.This type of software consists of programs that make it possible forother programs to be written or modified, translated into machinelanguage, or stored until they are used.1-16 OWNER S MANUAL