Introduction aux ordinateurs

L'horloge en temps réel (RTC) synchronise les signaux du système grâce à un cristal produisant des impulsions, tandis que la puce CMOS, alimentée par une batterie, conserve les informations essentielles lorsqu'elle est éteinte.

Le BIOS, ou système d'entrée/sortie de base, fait l'interface entre l'OS et la carte mère, stockant des configurations en ROM.

Le processeur

• The Central Processing Unit (CPU) is the ordinateur's brain.
• It's a microchip that manipulates and processes binary data (0 and 1).
• Different types of processeurs exist with varying speeds ("frequency") and capabilities.
• The CPU is plugged into a specific socket or slot (slot or socket).

Instruction

• An instruction (operation) tells the CPU what to do.
• Instructions are stored in main memory.
• Instructions consist of an operation code and operands.

Les connecteurs de mémoire vive (RAM)

• RAM (Random Access Memory) stores data temporarily during operation.
• RAM is volatile; data is lost when power is off.
• Different types of RAM exist (DRAM and SRAM).
• RAM comes in different sizes and speeds/frequencies, these are important for computer performance.

Les connecteurs d'extension

• Slots are receptacles for expansion cards to increase functionality(e.g., graphics card, sound card, network card).
• Differents types of expansion slots are available.

Les connecteurs d'entrée-sortie

• I/O (input/output) ports connect peripherals, such as monitors, keyboards, mice, printers.
• Different types of ports include serial ports, parallel ports, USB ports, Ethernet ports, and display ports.

Le boîtier

• The case protects internal components and provides mounting points for other devices.
• It includes power and reset buttons.
• It includes cooling and airflow features.

Bloc d'alimentation

• The power supply adapts power from the external wall socket to the voltage levels that the computer components require.
• The power supply must provide enough power(wattage).

Mémoire

• Computer memory stores data, both permanently and temporarily
• Permanent storage : hard drive, solid-state drive, CD-ROM, DVDs.
• Temporary storage: RAM.

Mémoire vive (RAM)

• RAM is the computer’s working memory.
• It stores programs and data that the CPU currently needs.
• It is volatile, meaning that data is lost when the computer's power is turned off.

Mémoire morte (ROM)

• ROM stores information permanently on the computer, even when the power is off.
• Programs often embedded on ROM are used to initialize the computer.
• BIOS is an example of a programme embedded (part of the ROM).

Mémoire flash

• Flash memory is non-volatile.
• It is used in various devices like USB drives and memory cards for permanent storage.

Différents types de mémoires de masse

• Mass storage devices store data permanently; for example, hard drives, solid-state drives, etc.

Le disque dur

• A hard disk drive stores data permanently.
• It uses magnetic storage to save data.
• A hard drive is composed of spinning platters with read/write heads to access data.
• An interface (e.g., IDE, SATA, SCSI) connects it to the motherboard, allowing communication.

Mémoire flash

• Flash memory is rewritable, non-volatile storage.
• It's found in memory cards, USB drives, and many other devices.

Les réels en virgule flottante

• Floating-point numbers (e.g., 3.14159)
• Represent real numbers in computers using base 2 calculations and fixed bit allocations.
• Includes a sign bit, exponent (for precision), and mantissa (for digits).
• Various representation strategies exist for optimized storage and calculations.

Séquence d'amorçage

• Sequence of events initiated on power-up (or restart)
• The sequence includes tests to ensure equipment (hardware) is functional as expected and prepares for the operating system.
• BIOS initializes hardware.
• BIOS locates boot sector.
• Boot sector initializes the system to boot Windows.

Le codage des informations

• Instructions and data in a computer are represented using binary code (0s and 1s).
• There are different numerical bases (e.g., decimal, binary, octal, hexadecimal) to represent the same values.
• The most common base used in representing data in a computer is the binary system, using only two digits: 0 and 1 to represent values.
• Other bases are also used, but they are more difficult to calculate and memorize.
• Octal and hexadecimal systems are used primarily in representing and converting between binary and decimal numbers/symbols rather than representing data/instructions directly or as the sole representation methods .

L’hexadécimal

• In the hexadecimal system (base 16), each digit is represented by 4 binary digits (bits).
• This system can compactly represent decimal numbers, facilitating data manipulation and conversion within computers

L'octal

• The octal system (base 8) is another alternative to binary representation for numbers.
• In the octal system, each digit represents 3 binary digits.