CASE STUDY 1

University of Southeastern Philippine

Institute of Computing

OPERATING SYSTEMS

Second Semester – SY 2010-2011

Name: Maria Edna Hernandez

Section: BSIT 3

Case Study #1:

Give an example OS (Specific) for each of the following categories of OS:

1.Batch Systems

* Batch is not an operating system, but a scripting language. Batch can for example be used to create a shell for MS-DOS, to create drive mappings, et cetera.

*IBM’s OS360 is a popular batch processing system.

*Batch processing is execution of a series of programs (“jobs”) on a computer without manual intervention.

2.Interactive Systems

*Distributed interactive systems are composed of a number of components that interact, for example, by exchanging messages or by updating shared memory.

* UMLi Example (1) P. de Silva/N. Paton: User Interface Modeling in UMLi, IEEE Software 20(4) 2003, pp. 62-69 (b)

(b) UMLi user interface diagram

3. Real-time systems

*a novel software technology are called hard real-time operating systems

*The first category includes many commercial kernels (such as VRTX32, pSOS, 0S9, VxWorks, Chorus, and so on) that, for many aspects, are optimized versions of timesharing operating systems.

*In these systems, time management is realized through a real-time clock, which is used to start computations, generate alarm signals, and check timeouts on system services. Task scheduling is typically based on fixed priorities and does not consider explicit time constraints into account, such periods or deadlines.

*second category of operating systems includes the real-time extensionsof commercial timesharing systems. For instance, RT-UNIX and RT-MACH

*Represent the real-time extensions of UNIX and MACH, respectively. The advantage of this approach mainly consists in the use of standard peripheral devices and interfaces that allow to speed up the development of real-time applications and simplify portability on different hardware platforms.

4.Hybrid Systems

* A hybrid system is a dynamic system that exhibits both continuous and discrete dynamic behavior – a system that can both flow (described by a differential equation) and jump (described by a difference equation or control graph). Often, the term “hybrid dynamic system” is used, to distinguish over hybrid systems such as those that combine neural nets and fuzzy logic, or electrical and mechanical drivelines. A hybrid system has the benefit of encompassing a larger class of systems within its structure, allowing for more flexibility in modelling dynamic phenomena.

*Hybrid systems have been used to model several systems, including physical systems with impact, logic-dynamic controllers, and even Internet congestion.

* A ‘Hybrid System’ is defined as an environment consisting of both Electronic and Paper-based Records (Frequently Characterized by Handwritten Signatures Executed on Paper). A very common example of a Hybrid System is one in which the system user generates an electronic record using a computer-based system (e-batch records, analytical instruments, etc.) and then is require to sign that record as per the Predicate Rules (GLP, GMP. GCP).

5. Embedded Systems

* An embedded system is a computer system designed to perform one or a few dedicated functions often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs. Embedded systems control many devices in common use today

* Physically, embedded systems range from portable devices such as digital watches and MP3 Players, to large stationary installations like traffic lights, factory controllers or the systems controlling nuclear power plants. Complexity varies from low, with a single micro controller chip, to very high with multiple units, peripherals and networks mounted inside a large chasis or enclosure.