EPAM

 Lesson1. Computer Hardware Basics

Desktop Computer Components

A motherboard is a microlite printed circuit board, on which various microcircuits and expansion slots are soldered. It consists of:

  • a CPU socket into which a processor is inserted like a plug
  • DIMM Memory slots for installing RAM
  • a SATA connector for connecting a hard disk drive (HDD) and a solid state drive (SSD)
  • a northbridge, PCI slots, a CMOS battery, BIOS
  • a built-in sound card, a network card, a graphic card, USB ports

RAM stores the information about the commands that are executed, about programs, and about everything that is being worked with. It is not suitable for long-term storage, because the information disappears after a computer is turned off. Types: DIMM (dual in-line memory module), SO-DIMM (small outline DIMM), DDR SDRAM (versions 2, 3, 4).

A hard disk drive and a solid state drive ensure long-term storage of information.







We can convert number to hex or binary and count the number of bytes needed, but there is an easier way. Any positive integer  has exactly  bits when  because  is a minimum binary number requiring  bits (one and a string of  zeros) and  is a maximum binary number requiring  bits (a string of  ones). This can be stated in another way: the number of bits is the exponent of the smallest power of 2 greater than the number. Mathematically this means that we should find logarithm in base 2 of our number, round it down, and add 1.

⎣⎦

So, we need at least 26 bits which is 4 bytes.

We can check the answer by doing conversion to hex, . Every two digits in hex is one byte. There are 7 digits, we need at least 4 bytes.





Комментарии

Отправить комментарий

Популярные сообщения из этого блога

Lesson1: JDK, JVM, JRE

Изображение
1. Compiler - takes the entire programming code written in high language and translates the whole of it into machine code at once. After this process the an executable file will be ready to run. The translation takes some times to be done, but after that execution is so fast. 2. Interpreter - takes each single instructions of the code translates it and then executes it on its own. The translation step is before the program runs is fast, but execution is slow. JDK = JRE + development tools JRE = JVM + library class JDK -> Java Development Kit. A kit which provides the environment to develop and execute (run) Java program. JRE -> Java Runtime Environment. Provides environment to only run. JVM -> Java Virtual Machine f * Compiled: Fortran, C, C++, Pascal, Haskell, Rust, Go * Interpreted: JavaScript, PHP, Python, Ruby Java both compiled and interpreted language. Terminalda : javac Main.java yazdiqda, source fayli(.java) bytecode(.class) faylina cevirir. Terminalda: java Main (bu z...
Далее...

SE_21_Lesson_9: Initialization Blocks, Wrapper types, String class

Изображение
-> static block: package org.example.test3 ; public class Blocks { static { System . out .println( "In static block" ) ; } public static void method () { System . out .println( "In static method" ) ; } } package org.example.test3 ; public class Main { public static void main ( String [] args ) { Blocks . method () ; } } -> Class.forName() metodunu ishe salmaq: package org.example.test3 ; public class Blocks { static { System . out .println( "In static block" ) ; } } package org.example.test3 ; public class Main { public static void main ( String [] args ) throws Exception { Class . forName ( "org.example.test3.Blocks" ) ; } } -> non-static (instance) block: package org.example.test3 ; public class Blocks { static { System . out .println( "in static block" ) ; } { System . out .println( "in non static (instance) block...
Далее...

SE_21_Lesson_11: Inheritance, Polymorphism

->  instanceof anlayishi, misallarla izahi   package org.example.lesson_13 ; public class Ulubaba { public String ad ; public String soyad ; public Integer yash ; public void odunDogramaq () { System . out .println( "Ulubaba 50 kq odunu 1 saata dograyir" ) ; } } package org.example.lesson_13 ; public class Baba extends Ulubaba { public String hobbi ; public void otBicmek () { System . out .println( "Baba 1 hektar otu 1 gune bicir" ) ; } } package org.example.lesson_13 ; public class Main { public static void main ( String [] args ) { Baba baba = new Baba() ; System . out .println( baba instanceof Ulubaba ) ; System . out .println( baba instanceof Object ) ; } } -> Upcasting package org.example.lesson_13 ; public class Main { public static void main ( String [] args ) { Ulubaba u = new Baba() ; } } -> Downcasting Problemsiz situasiya: package org.example.lesson_13...
Далее...