M206 - TMA07 - Question 3
(i)a) A platform describes the set of architectures of a system and is based on a particular processor or family of processors i.e. Intel 8088, 8086, 80286, 80386, 80486 a25, Pentiums. Ideally any so are designed for a specific platform should run more or less unchanged on that platform, though in reality software for the earlier platforms in the series should be able to run on the latest platforms (backward compatibility) but the reverse is not true. An operating system is usually designed to run on a specific platform. Windows98 will run on a PC platform (80386 DX or better) but does not on a ac system, however an OS like UNIX can be found on PC platforms through to Mainframes though the versions of UNIX are still machine specific to some extent.
b) CMOS is used to store configuration details such as COM port addresses, type and size of Hard disk (usually set for Auto Configure these days), where to and in which order to look for devices to boot from and many more user definable settings. The CMOS settings are kept alive by a small backup battery when the machine is powered off. CMOS is used in the Boot Process in the following way for a PC, On power on the BIOS (Basic Input Output System) starts to perform instructions held in its ROM. The configuration details held in CMOS are then read and used by BIOS, since BIOS needs to know how much memory, size of hard disk etc. BIOS makes use of these settings to allocate and assign basic services so that the operating system can then load.
c) Word size refers to the number of bits that the CPU can process at one time. The word size of a system is dependent on the following factors. size of CPU registers, number of bus data lines. A machine with an 8-bit word size processes 8-bits per instruction cycle whereas machines with a 64-bit word size process 64-bits per instruction cycle. It can be seen therefore that CPU performance for a machine with a large word size is going to be much greater than that of a machine with an 8-bit word size.
(ii) The Hospital Administration System consists of the following entity types.. Administration, Teams, Ward, Doctor, JuniorDoctor, Consultant Doctor, Patient, and Nurse. The Rest of this part (ii) has been removed as I made a complete hash of it!
(iii)a) File locking is necessary for data files on a network to prevent more than one user editing the same data. Should more than one user be editing the same data then the result will be unreliable, file locking prevents this as only one user has access to the specific data e.g. a specific record in a database. File locking is not typically required for applications because either they are run from the Server or local hard disk on a Netstation the application is loaded into RAM on the Netstation so the should never be any conflict i.e. an application is not edited.
b) The process of running a virus checker is known as a scan because that is exactly what the program is doing. A virus checker has a data file associated with it which contains thousands of virus signatures, during the scan process the checker is examining files and memory for evidence of these viruses and will alert the user if one is found. There are other methods of virus detection but all methods examine the files for evidence of a virus in some way, this is known as a scan. Virus signature is a unique series of bytes associated with a particular virus.
c) The CSMA/CD method is not required on a Token Ring network as the only time a Netstation can transmit on the network is when it has the Token and since there is only one token a collision will never happen.