Introduction to the Course Flashcards
How do computers process data?
under computer programs by computer programmers
What does the data items processed by computers form?
Data Hierarchy
The smallest data item in a computer
Bits
This can assume the value 0 or the value 1
Bits
Bits is short for
Binary Digit
A digit that can assume one of two values
Binary Digit
Functions performed by computers involve only the simplest manipulations of 0s and 1s
Bits
Tedious to work with data in the low-level form of bits
Character
Composed of characters or bytes (that
conveys meaning)
Field
Composed of related fields
Records
Composed of related records
File
In some operating systems, a file is viewed
sequency of bytes
Collection of data organized in tables
Database
What does the table include?
Records and Fields
Types of Programming Languages
Machine Languages, Assembly Languages, and High Level Languages
Language only computers can understand
Machine Languages
Generally consist of strings of numbers (ultimately reduced to 1s and 0s) that instruct computers to perform operations
Machine Languages
Machine Language is _______
Machine Dependent
a particular machine language can
only be used on only one type of computer
Machine Dependent
Disadvantage of Machine Language
Programming machine language was simply too slow and tedious
Uses English-like abbreviations to represent elementary operations (instead of using string of numbers that computers can only understand)
Assembly Languages and Assemblers
Translator Programs
Assemblers
Why do we need assemblers (or translator
programs)?
Because although such code is clearer to humans, it’s incomprehensible to computers until translated to machine language.
Disadvantage of Assembly Languages
Programmers still had to use numerous instructions to accomplish even simple tasks.
Developed to speed up the programming process
High-Level Languages and Compilers
Single statements could be written to accomplish substantial tasks
High-Level Languages and Compilers
Allow you to write instructions that look almost like everyday English and contain commonly used mathematical notations
Assembly Languages and Assemblers
one of the most widely used high level programming languages
C
Very flexible and powerful programming language originally designed in the early 1970s
C
When was C originally designed?
early 1970s
____ was written in C language
UNIX OS
C is a ____ programming language
compiled
a program that converts the c into a machine code instructions which do the job
compiler
What is C widely used to
develop systems that demand performance
Examples of systems
operating systems, embedded systems, real-time systems, and communication systems
Advantages of C
Efficiency and Standardization
Disadvantage of C in terms of coding
can write very tense code but it has side effect of making them hard to understand
Applications written in C
Linux, Windows, Android
What is needed for embedded systems
Embedded systems need to run as fast as possible
and conserve memory
When programming in C, we’ll use the following building blocks:
- C standard library functions
- Functions you create yourself
- Functions other people have created and made available to you
Machine language code can be called
object code
This occurs when the compiler cannot recognize a
statement because it violates the rule of the language
syntax error
Type of error when a compiler cannot recognize a
statement because it violates the rule of the language
compile errors, or compile-time
errors
A linker links the object code with the code for the missing
functions to produce an
executable image
It takes the
executable image from disk and transfers it to memory.
Loader
To load and execute a program, type and enter
./welcome
Linking command
gcc –o welcome welcome.c
