Computer Hardware and Software Components for Performance

Computer Hardware and Software Components

Software: Programs and Operating Systems

The machine consists of hardware capable of performing a variety of tasks. Electronic computer components need software to run. The programs will help us process information. A set of orders and instructions constitutes a program. A single program or a set of programs is a software application. We need to keep an operating system running, which allows software to process information using physical components.

Software Categories

• Operating system — manages hardware and provides services for applications.
• Application software — processes personal and end-user information.

Physical Components (Hardware)

Physical components include:

1. CPU (Central Processing Unit) — consists of the ALU and the control unit (CU).
2. RAM — volatile main memory.
3. Control units — control signals and sequencing.
4. Input/Output units — manage communication with peripherals.
5. Buses — interconnects between components.
6. Peripheral units — external devices and I/O units.

CPU Role and Responsibilities

The CPU manages and controls everything that happens inside a computer. The CPU, or processor, is responsible for supervision and execution of operations carried out within the computer. Its main task is to receive and process information and to load instructions into RAM for the execution of programs.

CPU Internal Components

1. Instruction register — stores the instruction currently being executed.
2. Program counter (register) — contains the memory address of the next instruction to execute.
3. Controller and decoder — interprets instructions for later processing.
4. Sequencer — generates the microinstructions needed to run operations.
5. Clock — provides a succession of electrical pulses at a constant rate to synchronize operations.

Arithmetic Logic Unit (ALU)

The ALU is responsible for carrying out arithmetic and logical operations on information.

Memory: RAM and ROM

Memory types include RAM and ROM. Types of RAM commonly considered are:

• DRAM
• SRAM
• SDRAM
• DDRAM

Buses: Purpose and Types

The bus is the element responsible for establishing proper interaction between different components. Buses connect memory, CPU, and peripherals and manage data transfer and control signals. There are different bus topologies and categories:

• Data bus — carries actual data between components.
• Address bus — carries memory addresses that identify where data should be read or written.
• Control bus — carries control signals, such as read/write and interrupt lines.

Shared and Dedicated Buses

Some buses are shared among memory and peripherals for read/write operations (I/O). Shared buses may not allow direct memory access (DMA). A dedicated bus (or dedicated channels) can allow DMA between memory and peripherals and may treat memory and peripherals as separate components. Dedicated systems can contain several subcategories of buses such as data bus, address bus, and control bus.

Numeric Representations and Bus Control

Various numeric representations are used inside computers and affect how data is transmitted on buses and processed by the ALU and control logic:

• Sign-magnitude: uses a sign bit — 0 for positive, 1 for negative.
• Excess (biased) representation: adds a fixed bias (for example, +128 in an 8-bit biased scheme) to represent signed values.
• Two's complement (2's complement): negative numbers are obtained by inverting the bits and adding 1; this representation is widely used for integer arithmetic.
• Binary-coded decimal (BCD): can be used in packed or unpacked formats; unpacked BCD uses 4-bit groups for each decimal digit. Sign information is sometimes stored in a separate nibble (for example, a pattern such as 1111 may be used as a sign indicator depending on encoding conventions).

Control buses and numeric representation rules determine how binary values are passed, interpreted, and transformed by the CPU and peripherals. For example, two's complement conversion, sign-bit handling, and BCD adjustments (such as adding 1 in certain BCD correction steps) are part of the control and arithmetic logic tasks performed when executing instructions.