1. Algoritmos y Programacion
Computer Languages
Machine language
A collection of binary instructions understood by a given type of CPU
Non-standard; low-level of detail related to the given hardware
Very hard to understand by human programmers
In order to be executed, any program must have been previously translated into machine language.
Assembly language
Mirrors closely a given machine language, only more readable by humans: uses mnemonics for instruction codes and names for variables
High-level languages
Closer to the human way of expression, using higher-level of abstraction concepts from the application area for which it is intended
Mostly standardized, thus independent of a given hardware.
The downside: computers do not understand high-level languages.
Need a compiler to convert programs written in high-level languages into machine language.
Algoritmos y Programacion
JMHL

2. Example: Adding two numbers together
Suppose the two numbers we want to add are stored in
memory locations 137 and 138, and we want to store the
result in memory location 139.
The following instructions need to be executed by the CPU:
Fetch the contents of memory location 137 and store it in a register in the ALU
Fetch the contents of memory location 138 and add it to the contents of the register
Store the contents of the register in memory location 139
Algoritmos y Programacion
JMHL

3. Example: Adding two numbers together
The machine language code to do this is:
opcodes
operands
Algoritmos y Programacion
JMHL

4. Example: Adding two numbers together
The assembly language code to do this is:
LOAD $137, R1
ADD $138, R1
STORE R1, $139
With assembly language it is also possible to assign labels
to memory locations. If A is a label for location 137, B is
a label for location 138, and C is a label for location 139, the
assembly language code can be written as
LOAD A, R1
ADD B, R1
STORE R1, C
Algoritmos y Programacion
JMHL

5. Example: Adding two numbers together
High-level languages were developed to simplify programming.
To add two numbers in C++, the programmer uses the expression
c = a + b;
Similar expressions are used in other programming languages
FORTRAN
C = A + B
APL
C  A + B
COBOL
ADD A TO B GIVING C.
Algoritmos y Programacion
JMHL

6. Algoritmos y Programacion
High-Level Languages
Algoritmos y Programacion
JMHL