Microprocessor: Definition

Microcomputer
The term microcomputer is used to describe a system that includes at minimum a microprocessor, program memory, data memory, and an input-output (I/O) device. Some microcomputer systems include additional components such as timers, counters, and analog-to-digital converters. Thus, a microcomputer system can be anything from a large computer having hard disks, floppy disks, and printers to a single-chip embedded controller.

Microcontroller
A microcontroller is a single-chip computer. Micro suggests that the device is small, and controller suggests that it is used in control applications. Another term for microcontroller is embedded controller, since most of the microcontrollers are built into (or embedded in) the devices they control.

Microcomputer Block Diagram:

Intel Microprocessors and their Details:

MICROPROCESSOR	YEAR	SPEED	WORD LENGTH	TRANSISTORS	MIPS
Intel 4004	1969	108 KHz	4-bit	2,300	.06
Intel 8008	1972	200 KHz	8-bit	3,500	.06
Intel 8080	1974	2 MHz	8-bit	6,000	.64
Intel 8086	1978	4.47 MHz	16-bit	29,000	.66
Intel 8088	1981	4.47 MHz	16-bit	29,000	.75
Intel 80286	1982	12 MHz	16-bit	134,000	2.66
Intel 80386	1985	16-33 MHz	32-bit	275,000	4
Intel 80486 (i486)	1989	20-100 MHz	32-bit	1.2 Million	70
Intel 80586 (Pentium)	1993	75-200 MHz	32-bit	3.3 Million	126 - 203
Intel Pentium Pro	1995	150-200 MHz	32-bit	5.5 Million	300
Intel Pentium MMX	1997	166-233 MHz	32-bit	4.5 Million	-
Intel Pentium II	1997	233-450 MHz	32-bit	7.5 Million	-
Intel Pentium III	1999	450-933 MHz	32-bit	Over 9.5 Million	-
Intel Itanium Processor (formerly Merced Processor)	2000	1 GHz	64-bit	15,000,000	1,200

Speed is measured in terms of Hz. 1 Hz=1 cycle per second (1 Particular Job per second)
In a single processors millions of transistors may be used.
MIPS: Millions of Instruction Per Second (The speed in terms of Instruction performed in a second)
The First Microprocessor was the 4-bit Intel 4004 Processor.