(02) OS Types

The desire to save money and create faster systems.

What is the primary motivation for computer scientists to seek more efficient operating systems?

They hate being overly idle.

What attitude do computer scientists typically hold toward system idleness?

They keep several jobs in memory simultaneously.

What is the core characteristic of multiprogrammed batch systems regarding memory?

They only allowed one program in memory at a time.

How did previous batch systems differ from multiprogrammed systems regarding memory usage?

The I/O processing of another job.

In a multiprogrammed system, what overlaps with the computation of one job?

CPU scheduling.

What specific management need was introduced by the advent of multiprogrammed systems?

Timesharing or multitasking systems.

Which type of operating system first allowed users to interact via a keyboard?

To make each user feel as if they have the entire machine to themselves.

What is the psychological goal of a timesharing system for the individual user?

Response time.

What specific performance metric do timesharing systems attempt to optimize?

Time-slicing.

Timesharing systems are fundamentally based on the concept of _.

It is divided equally or nearly equally among all users.

How is the CPU allocated among users in a timesharing system?

In the 1970s.

When did desktop systems, or personal computers (PCs), first appear?

Pasocon.

What is the Japanese term for personal computers mentioned in the text?

The space race.

What historical technological era drove the miniaturization that allowed for desktop systems?

Miniaturization.

Moore's Law is an empirical observation of what trend in electronics?

Parallel systems or tightly-coupled systems.

What is another name for multiprocessor systems?

By using more CPUs to complete more work in less time.

How do multiprocessor systems achieve increased throughput?

Economy of scale.

Which advantage of multiprocessor systems refers to saving money by sharing peripherals?

By providing redundancy and fault tolerance.

How do multiprocessor systems improve system reliability?

Each CPU has a specific role and different hardware permissions.

What defines Asymmetric Multiprocessing (AMP) regarding CPU roles?

The master CPU running the O/S.

In an Asymmetric Multiprocessing system, which entity assigns tasks to the other processors?

Most systems at the time were designed for only one CPU.

Why was implementing a second CPU difficult for early operating systems?

All CPUs are identical and have identical hardware access.

What is the defining hardware characteristic of Symmetric Multiprocessing (SMP)?

Through shared memory.

How do CPUs communicate in a Symmetric Multiprocessing (SMP) system?

Ensuring the overall load is as balanced as possible.

What is a primary goal of the O/S in an SMP system regarding processor workload?

Loosely-coupled systems.

What is the alternative name for distributed systems?

To facilitate the use of geographically-distributed computing resources.

What is the primary function of distributed systems?

Software.

Distributed systems support the sharing of both hardware and _ resources.

To make several CPUs work together on a specific task.

What is the primary purpose of clustered systems?

Through a high-speed local area network (LAN).

How are the components of a clustered system typically linked together?

Storage.

What resource is commonly shared among the nodes in a clustered system?

Two or more hosts running applications while monitoring each other.

Define symmetric clustering.

One host runs applications while another remains in hot standby mode.

Define asymmetric clustering.

To act as a backup that takes over if the active host fails.

What is the function of a 'hot standby' host in a clustered system?

Specialized applications like flight control, subways, or medical monitors.

Where are real-time systems typically utilized?

Response to physical events within a fixed amount of time.

What is the fundamental guarantee provided by a real-time operating system?

The deadline is critical and must be met regardless of system load.

What is the primary constraint of a Hard Real-Time system?

To control a physical device.

Hard real-time systems are typically used for what purpose?

A computer-assisted robotic arm.

Provide an example of a Hard Real-Time system application.

The deadline is important but not critical for system failure.

How does a Soft Real-Time system differ from a Hard Real-Time system regarding deadlines?

Achieving synchronization between different outputs.

What is the typical purpose of a Soft Real-Time system?

A movie player or video game console.

Provide an example of a Soft Real-Time system application.

Limited main memory, processor speed, and smaller display screens.

List three common hardware concerns for handheld systems.

They restrict the complexity of programs and the operating system.

How do hardware limitations affect software on handheld devices?

Multiprogrammed systems.

Which OS type was the first to make decisions for users, necessitating scheduling?

To ensure data reaches the appropriate processor.

In SMP, why must the operating system carefully control I/O?

Moore's Law is the empirical observation of miniaturization in electronics.

What is the relationship between miniaturization and Moore's Law?

Running the O/S and assigning instructions to other processors.

What is the main task of a master CPU in an Asymmetric Multiprocessing setup?

Symmetric clustering.

Which clustering scheme allows for both active application running and mutual monitoring?

Overlap of I/O and computation in multiprogrammed systems.

The concept of 'print spooling' is a precursor to the general form of what OS feature?

Distributed systems.

Which type of system is specifically designed to handle geographically-dispersed resources?

They share resources like memory and peripherals closely.

What does 'tightly-coupled' imply about the processors in a multiprocessor system?

They are independent systems connected by a network.

What does 'loosely-coupled' imply about the components of a distributed system?

Two (the user job and the O/S).

In multiprogrammed systems, what is the maximum number of programs in memory if only one user job is loaded?