computer systems nat 4/5 computing science translator programs
TRANSCRIPT
Computer Computer SystemsSystems
Nat 4/5 Computing Nat 4/5 Computing ScienceScience
Translator ProgramsTranslator Programs
Lesson AimsLesson Aims By the end of this lesson: All pupils will be able to:
Describe and compare the following types of languages:
Machine Code High Level Languages Describe why High Level Languages require
translation. Describe how interpreters and compilers
function.
Types Of LanguagesTypes Of Languages Machine Code is made up of only 2
symbols. 1 and 0 (On and Off)
High Level Languages such as Visual Basic are written using some English words. They are not written IN english!
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High Level LanguagesHigh Level Languages
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Why do we need them?Why do we need them? The source code you write is instructions
for the computer They are in a High Level Language
The computer needs these instructions translated into machine code It’s the only language it understands!
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Types of TranslatorsTypes of Translators These programs convert High Level
Language Source code into machine code (binary)
Interpreter Translates and executes one line at a time
Compiler Translates and executes the entire program
at once This program can then be ran repeatedly
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Think complete!
InterpreterInterpreter Functions like a spoken language interpreter.
Translates and executes a single line at a time
The interpreter is ALWAYS loaded in memory
Error feedback is provided line by line Like in Smallbasic
Interpreted programs have to be re-interpreted every single execution
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How an interpreter worksHow an interpreter works
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Original Source Code
Pctoutput.print “Hello”
Pctoutput.isible = true
Interpreter
1001 1000 1100 1110 00111001 1000 1100 1110 0011Syntax Error
How the compiler worksHow the compiler works
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Original Source Code
Pctoutput.print “Hello”
Pctoutput.isible = true
Compiler 1010 1010 1010 0111 00111001 1000 1100 1110 0011
Syntax Error
Object Code
Can be saved and ran later
SummarySummary Compilers translate source code once into
an executable program Only has to be translated once! Cannot see the source code in a compiled
program
Interpreters translate source code line by line Always has to be re-interpreted Spots errors line by line
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