CSIT 230 Computer Systems Overview

• CSIT 230 Computer Systems, School of Computing, Montclair State University, Dr. Prince Waqas Khan

Course Objectives

• Introduce fundamental aspects of computer systems
• Explore computer architecture and organization
• Develop skills in Boolean logic and circuit design
• Study digital design principles
• Learn Assembly language programming
• Apply theoretical concepts to practical computer system design

Further Reading

• "Computer Systems Digital Design, Fundamentals of Computer Architecture and Assembly Language" by Ata Elahi

Grading Policies

• Assignments account for 20% of the grade
• Midterm Exam accounts for 25% of the grade
• Final Exam accounts for 45% of the grade
• Discussion accounts for 10% of the grade

CSIT 230 Overview

• Other policies are detailed in the syllabus

Key Questions to be Answered

• How does a computer represent data?
• What operations does a computer understand?
• How a program executes?
• What happens when a user types on the keyboard?
• How do text and drawings appear on a display?
• How do things work inside this wondrous box?

Computer Systems

• Encompass both hardware and software components

Software Components:

• System Software: Includes Operating Systems and Device Drivers.
• Application Software
• Language Processors: Assemblers, Compilers, and Interpreters.

Historical Highlights in Computing:

• 2700 BCE: Abacus
• 140 B.C.: The Antikythera Mechanism
• 1642: Pascal's Calculator (Pascaline)
• 1822: Analytical Engine (Charles Babbage)
• 1941: Atanasoff-Berry Computer (ABC)
• 1945: Electronic Numerical Integrator and Calculator (ENIAC)
• 1971: First PC
• 1981: First commercial laptop
• 2024: Quantum computers being developed

Abacus

• Abacus is an ancient calculating tool from 2300-2700 B.C. capable of performing the four basic arithmetic operations.

Antikythera Mechanism

• Built in ancient Greece between 150-100 B.C.
• Considered the world's first analog computer
• Designed to align the number of lunar months with years

Pascaline

• Blaise Pascal invented and built the Pascaline to help his father, a tax collector.

Analytical Engine

• Mechanical computer designed to compute mathematical tables, including logarithmic and trigonometric functions

Atanasoff-Berry Computer (ABC)

• The world's first electronic digital computer
• Designed to speed up and improve the accuracy of scientific calculations.
• It was the first to use binary digits

ENIAC

• Electronic Numerical Integrator and Computer
• The world's first general-purpose electronic computer

Kenbak-1

• Released in early 1971, it is considered to be the world's first personal computer.
• Built using small-scale integrated circuits and did not use a microprocessor

Osborne 1

• The first commercially successful portable computer, released in 1981

Basic Components of a Computer

• Memory Unit
• Input Unit
• CPU: Registers, ALU, Control Unit
• Output Unit
• Storage

Analog Signals

• Analogue means something continuous. A set of specific points of data and all possible points between them.
• An analog signal is a signal whose amplitude is a function of time and changes gradually as time changes.
• Analog signals can be classified as nonperiodic (aperiodic) and periodic signals.

Periodic Analog Signals

• Repeats its pattern at regular intervals, like a sine wave with a consistent frequency

Non-Periodic Analog Signal

• Does not repeat its pattern, like a voice signal which constantly changes in amplitude and frequency

Characteristics of an Analog Signal:

• Cycle
• Frequency
• Amplitude
• Phase

Cycle

• A cycle/period in an analog signal refers to one complete repetition of its waveform.
• Can be measured from its zero point to its positive peak, then back down to its negative peak, and finally returning to zero again.

Frequency

• The rate of change with respect to time
• The number of cycles in 1 second
• Represented in Hertz (Hz)
• Equation for frequency is f = 1/T
• T is time

Amplitude

• Refers to the vertical height or magnitude of the wave
• Represents the strength or intensity of the signal at any given point in time

Phase

• Describes the position of the waveform relative to time
• Typically measured in degrees (0-360)

Frequency Domain Representation

• Displays the distribution of a signal's energy across different frequencies.
• The horizontal axis represents frequency
• The vertical axis represents the amplitude of the signal
• Appears as a single peak at the dominant frequency

Digital Signals

• Digital refers to something discrete
• Represent data using discrete values
• Represented by two voltages: one voltage represents the number 0 in binary, and the other voltage represents the number 1 in binary. -Logic Level HIGH is True, On, 1 -Logic Level LOW is False, Off, 0

Key differences between analog and digital signals

• Analog signals feature a continuous waveform that varies smoothly over time
• Digital signals feature discrete values represented as binary (0s and 1s)
• It is more complex to store analog, requires high-quality media, whereas digital is easier
• Examples of analog are radio waves, human voice, vinyl records, while digital is examples are CDs, digital audio files, computer data
• Generally less expensive for simple analog systems
• Analog is more complex to process and manipulate, whereas digital is easier

Key Takeaways

• Course Introduction: Objectives and Policies
• Background: History and basic computer components
• Signals: Understanding analog vs digital signals
• Next Lecture: Number Systems (Decimal, binary, octal, hexadecimal)