1.2 Microsoft Windows; 1.3 Unix; 1.4 The Web; 1.5 Remote Computing

What is GUI?

• Graphical User Interface

What are the properties of a window of Windows 3.x? (5)

• Windows can overlap each other

• Exactly one Window is active

• The active Window is in the front, fully visible

• Windows can be resized and moved on the screen

• Windows provide buttons for minimizing, maximizinf and closing the Window

When is the message “This program is not responding“ shown?

• When the program fails to regularly check for messages and handle them

What is Unix?

• A familiy of operating systems developed for mainframes

Who were the main developers of Unix? (2)

• Ken Thompson

• Dennis Ritchie

What is the formulation of the Unix philosophy formulated by Douglas McIllroy? (3)

• Write programs such that they do only one thing and they do it well

• Write programs such taht they can work together

• Write programs such that they work on textual streams as this is the universal interface

What is the formal summary of the Unix philosophy?

• Do only a single thing at a time and do it well

What is the informal summary of the Unix philosophy?

• KISS: Keep it Simple, Stupid!

What is the Gancarz formulation (probably not exam-relevant)?

• Small is beautiful

• Make each program do one thing well

• Build a prototype as soon as possible

• Choose portability over efficiency

• Store data in flat text files

• Use software leverage to your advantage

• Use shell scripts to increase leverage and portability

• Avoid captive user interfaces

• Make every program a filter

What is POSIX?

• Portable Operating System Interface

Why was POSIX created?

• To create a standard to describe clearly and independent from a concrete implementation definitios of terms, system interface and the comman line interpreter

What are the two parts as which the Web runs?

• Backend

• Frontend

What is the backend?

• The part of the web in which the core of the application is running in a compute center

What is the frontend?

• The part of the web which runs locally on the client device in a browser

What is SOA?

• Service-Oriented Architectures

What is Remote Computing?

• All types of using a computer remotely via a network connection

Name 6 examples of remote computing?

• Supercomputers

• Amazon Web Services

• Microsoft Azure

• Satellites

• Drones

• Robots

On which protocols is based remote computing when the remote computer runs a GUI? (3)

• Microsoft RDP protocol

• X Windows Protocol

• VNC protocol

What are other commonly-used access methods for remote computing? (3)

• Serial Terminal

• Telnet

• SSH

How does a Serial Terminal work?

• Whenever a key is pressed on the client, it is transmitted over a set of cables following a certain protocol to be retrieved on the remote device-

• It connects client computer with remote computer, emulating sitting in front of the remote computer, even when this latter does not have keyboard or monitor.

Which is the msot common standard for the formulation of control characters for Serial Terminals?

• VT-100 Terminal

What is the Baud-rate?

• Is a measurement of how many bits per second shall travel over the cable of a Serial Terminal connection

What is parity?

• Electormagnetical interferance that might lead to failures in a Serial Terminal connection

What is the telnet protocol? (2)

• An Internet protocol on top of a network technology stack

• Allows to create a terminal connection between two computers connected in a local area network (or over the Internet) using the IP address

Why is telnet protocol not used (much) in these days?

• Because the connection is not authenticated and encrypted (prone to hacker interferance)

What is the most common approach for remote computing?

• SSH

What is the meaning of SSH?

• Secure Shell

What is SSH? Why is it special?

• A protocol that allows the creation of a remote connection with a command line interface

• It assigns a public and a private key to each computer to authenticate the remote host

• It uses the same keys to encryptate the information