III.Speaking exercises:

Exercise 1

Device driver

A device driver is a specific type of computer software developed to allow interaction with hardware devices. Typically this constitutes an interface for communicating with the device, through the specific computer bus or communications subsystem that the hardware is connected to, providing commands to /or receiving data from the device, and on the other end, the requisite interfaces to the operating system and software applications. It is a specialized hardware-dependent computer program which is also operating system specific that enables another program, typically an operating system or applications software package or computer program running under the operating system kernel, to interact transparently with a hardware device, and usually provides the requisite interrupt handling necessary for any necessary asynchronous time-dependent hardware interfacing needs.

Function of the device driver.

The function of the device driver is then to translate these OS mandated function calls into device specific calls.

Kernel

In modern operating systems, interrupts are handled by the operating system's kernel. Interrupts may come from either the computer's hardware, or from the running program. When a hardware device triggers an interrupt, the operating system's kernel decides how to deal with this event, generally by running some processing code, or ignoring it.

Exercise 2

1.What is a device driver?

2.What is the function of interrupts?

3.What is one of the most basic forms of time-sharing?

4. What is the key design goal of device drivers?.

IV. Writing exercises:

Exercise 1

Command driven 2.Various menus.3.Network connectivity. 4.Text terminal.

Exercise 2

A single clear aim,

Typical text terminal,

The commands and what they do.

Lesson 9

II.Reading exercises:

Exercise 2

1. "Kernel" – the part of an operating system that provides the most basic services to application software running on a processor.

2. The most basic category of kernel services is Task Management.

3. The Task Scheduler controls the execution of application software tasks, and can make them run in a very timely and responsive fashion.

4. The key difference between general-computing operating systems and real-time operating systems is the need for " deterministic " timing behavior in the real-time operating systems.

Exercise 3

1b, 2d, 3a, 4c..

Exercise 4

1.Kernel serviced. 2. Pass..

III.Speaking exercises:

Exercise 1

Kernel

"Kernel" – the part of an operating system that provides the most basic services to application software running on a processor. The "kernel" of a real-time operating system ("RTOS") provides an "abstraction layer" that hides from application software the hardware details of the processor (or set of processors) upon which the application software will run.

Abstraction layer

"Abstraction layer" hides from application software the hardware details of the processor (or set of processors) upon which the application software will run.

Intertask communication and synchronization.

The second category of kernel services is Intertask Communication and Synchronization. These services make it possible for tasks to pass information from one to another, without danger of that information ever being damaged. They also make it possible for tasks to coordinate, so that they can productively cooperate with one another

Random elements

Random elements in service times could cause random delays in application software and could then make the application randomly miss real-time deadlines – a scenario clearly unacceptable for a real-time embedded system.

Exercise 2

1.What does the kernel of a real-time operating system provide?

2.How many categories of basic services does RTOS kernel supply?

3.What can Random elements in service times cause?

4.What is the key difference between general-computing operating systems and real-time operating systems?.