Notes, abstracts, papers, exams and problems of Computers

80386 Processor State After Reset

After a reset, the 80386 processor is initialized to a specific state to ensure proper operation. Here's an explanation of the processor state after reset:

1. Operating Mode

The processor is initially in Real Mode after a reset. Real Mode is a backward-compatible mode with earlier x86 processors like the 8086/8088. In Real Mode, the processor operates with a 20-bit address bus, allowing it to address up to 1 MB of memory.

2. Segment Registers

The segment registers CS, DS, SS, and ES are set to 0x0000, pointing to the bottom of the physical memory. In Real Mode, these segment registers are 16 bits wide.

3. Instruction Pointer (IP)

The instruction pointer (IP) is set to 0xFFFF, indicating the initial address from which... Continue reading "Understanding the 80386 Processor State After Reset" »

Constructor

A constructor is a special method in object-oriented programming that is automatically called when an instance (object) of a class is created. The main purpose of a constructor is to initialize the object's attributes (properties) and allocate resources if needed. Constructors have the same name as the class and do not have a return type.

Example of a Constructor

Here is an example in Python:

class Person:
    def __init__(self):
        self.name = "John Doe"
        self.age = 30

# Creating an instance of the Person class
person = Person()

print(person.name)  # Output: John Doe
print(person.age)   # Output: 30

In this example, __init__ is the constructor method in the Person class. It initializes the name and age attributes of the... Continue reading "Understanding Constructors and Class Variables in OOP" »

Microprocessor vs. Microcontroller

ii) Differentiate Between a Microprocessor and a Micro-Controller

Microprocessor

Definition:

A microprocessor is a central processing unit (CPU) on a single integrated circuit (IC) chip that performs the processing functions of a computer.

Functionality:

• It only includes the CPU core and lacks other components like memory, I/O ports, timers, and other peripherals.
• Requires external components like memory (RAM, ROM), input/output devices, timers, and other peripherals to function as a complete system.

Usage:

• Primarily used in systems requiring high computational power and flexibility, such as desktop computers, laptops, servers, and high-end embedded systems.
• Suited for applications where customization of peripherals

What is Mathematical Logical Thinking?

These are the skills students develop associated with logical and mathematical concepts, reasoning, comprehension, and exploration of the world through real proportions, thus strengthening more abstract aspects of thought.

Geometry with Dinosaurs

This activity involves cutting out various geometric shapes with EVA rubber. Children will then create their own dinosaurs using these shapes. Through this activity, they can learn geometric shapes, count the number of elements used in each dinosaur (like the sides of the shapes), and create new geometric shapes from the ones they already have.

Logical Reasoning with Chupa Chups

This activity consists of creating logically structured material and playing with it using... Continue reading "Developing Logical and Mathematical Thinking in Children" »

Binary Parallel Adder

A binary parallel adder is a digital circuit that adds two binary numbers in parallel, meaning all bits are added simultaneously. It typically consists of full adders arranged in parallel, with each full adder adding corresponding bits from the two input numbers.

BCD Adder

A BCD (Binary Coded Decimal) adder is a specific type of binary parallel adder designed to add two BCD numbers. BCD numbers are decimal digits encoded in binary, where each decimal digit is represented by its 4-bit binary equivalent.

Truth Table for a 4-bit BCD Adder

Here's the truth table for a 4-bit BCD adder:

Diagram

In the truth table:

• A3 A2 A1 A0 represents the first BCD number (A).
• B3 B2 B1 B0 represents the second BCD number (B).
• Cin represents the carry-

Ejercicio de descuentos:

#!/bin/bash

read -p "¿Desea el billete también de vuelta? (s/n): " idavuelta

until [ $idavuelta=="s" ] || [ $idavuelta=="n" ]; do

read -p "¿Desea el billete también de vuelta? (s/n): " idavuelta

done

read -p "¿Tiene carnet joven? (s/n): " carnetjoven

until [ $carnetjoven="s" ] || [ $carnetjoven="n" ]; do

read -p "¿Tiene carnet joven? (s/n): " carnetjoven

done

descuento=0 billete=20

if [ $idavuelta="s" ]; then

descuento=20

billete=" expr $billete \* 2'

fi

if [ $carnetjoven="s" ]j then

descuento=30

fi

costefinal=`expr $billete \* \( 100 - $descuento \) / 100`

echo "El precio final del billete es $costefinal"

Ejercicio de medias:

#!/bin/bash

acu=0

cont=0

read -p "Introduce un numero: " num

while [ $num -ne 0 ]; do

acu=`expr $acu + $num`

cont=... Continue reading "Shell script" »

Kako si lep danes 

What is Lorem Ipsum?

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.

What is Lorem Ipsum?

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard... Continue reading "dsdfs" »

DIRECTORY COMMANDS

– Directory commands: Commands that work with directories (pwd, ls, cd, mkdir, rmdir)

– File commands: Commands that allow you to manage files (cp, mv, sort, cut, paste, diff, rm, uniq)

pwd it lets you know where you are in the tree

Basic listing (ls): Displays files and directories in your current directory.

-F  To distinguish between files and directories

-a  show hidden files starting with a dot (.)

 -l parameter to produce a long listing.

Allows you to make copy of a file. 

– cp [option] source destination 

 -i option for interactive mode to give you a warning before overwriting an already existing file. 

 -p option to preserve file access or modification times of the original file for the copied file.

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