Introduction to Microcomputers

A microcomputer is a personal computer or a computer that runs on a microprocessor. Microcomputers, whether they be in the form of PCs, workstations, or laptop computers, are intended for individual use.


A microcomputer is composed of a microprocessor, which is a CPU on a microchip, a bus system, an I/O port array, and a memory system, which is usually housed in a motherboard.

🖥️
Personal Use

Designed for individual users

🧩
Integrated System

Components on a motherboard

🔌
I/O Capabilities

Port arrays for peripherals

What is a Microprocessor?

🔤Origin of the Term

The word comes from the combination micro and processor.

  • Processor means a device that processes numbers, specifically binary numbers, 0's and 1's.
  • Micro is a new addition that became significant in the 1970s.

⏳Historical Development

  • In the late 1960's, processors were built using discrete elements.
  • These devices performed the required operation, but were too large and too slow.
  • In the early 1970's the microchip was invented. All of the components that made up the processor were now placed on a single piece of silicon.
  • The size became several thousand times smaller and the speed became several hundred times faster.
  • The "Micro" Processor was born.

Evolution of Microprocessors

Intel released the 4004 and 8008 microprocessors, its first 4-bit and 8-bit microprocessors, respectively, in 1971 and 1972. These microprocessors' performance and design restrictions prevented them from being successful as general-purpose microprocessors.


Launched in 1974, the first general-purpose 8-bit microprocessor, the 8080, was later modified and given further functionality in 1977, making it a functionally complete microprocessor. This was known as the 8085 microprocessor.


The primary drawbacks of 8-bit microprocessors were their poor speed, restricted amount of general purpose registers, low memory addressing capacity, and weaker instruction set.


The first member of the 16-bit microprocessor family to be released in 1978 was Intel's 8086.

📊Intel Microprocessor Evolution

MICROPROCESSOR 4004 8008 8080 8085 8086
Year 1971 1972 1974 1977 1978
No. of Bits 4 8 8 8 16
Technology PMOS PMOS NMOS NMOS HMOS
MEMORY 4 KB 16 KB 64 KB 64 KB 1 MB
INSTRUCTION SET 45 48 246 246 -
SPEED - - - - 50 KIPS
NO. OF TRANSISTORS 2300 3500 4500 6500 29000
1971

Intel 4004

First 4-bit microprocessor

2300 transistors

1972

Intel 8008

First 8-bit microprocessor

3500 transistors

1974

Intel 8080

First general-purpose 8-bit microprocessor

4500 transistors

1977

Intel 8085

Enhanced version of 8080

6500 transistors

1978

Intel 8086

First 16-bit microprocessor

29000 transistors

Microprocessor Introduction

A microprocessor, frequently shortened to μP, is a single semiconductor integrated circuit (IC) that contains miniature transistors.


A computer system or portable device's central processing unit (CPU) is usually one or more microprocessors.


The development of the microcomputer was made possible by microprocessors.


A microprocessor is the central component of most workstations and desktop computers. Almost all digital devices, including clock radios and car fuel injection systems, use microprocessors that manage their logic.

🔍Key Differentiators

Microprocessors differ in three fundamental ways:

📝

Instruction Set

The collection of commands it is capable of carrying out.

📏

Bandwidth

The amount of bits processed in a single instruction.

⏱️

Clock Speed

Expressed in megahertz (MHz), dictates the number of instructions the CPU can process in a second.

⚡Performance Factors

The CPU's power increases with the value in both scenarios. A 32-bit CPU operating at 50MHz, for instance, has greater power than a 16-bit microprocessor operating at 25MHz.

🔄
Higher Bandwidth

More data processed per cycle

⚡
Higher Clock Speed

More cycles per second

🚀
Combined Power

Exponential performance increase