tailieunhanh - MultiBooks - Tổng hợp IT - PC part 154

Tham khảo tài liệu 'multibooks - tổng hợp it - pc part 154', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Backing storage is also called secondary storage external storage and auxiliary storage. Chapter 2 MICOPROCESSOR. Question 1. Cache Memory - Cache memory is a small amount of very fast store with faster access time than the main memory. - Cache memory is used to temporaryty store data instructions that are likely to be retrieved many times thus speeds up the processing of data. - Sits between main storage and the processor acting as holding area through which all data and instructions pass. - Old data in the cache memory is over written by new then cache is full. Question 2. Virtual Memory - Virtual memory makes use of both the main memory and backing store. - In a virtual memory sys each user has the illusion that his program is in the main memory all the time. - The sys maintains this illusion by keeping some of the unused portion of the program s code and data on a backing store device which is usually magnetic disk - The movement of the unused portion from the backing store to the mian memory is transparent to the users. - Please refer to diagram for virtual memory. Chapter 3 BATCH ONLINE AND REAL TIME PROCESSING SYSTEM. Question 1. Batch Processing System - Def Computer processing does not begin until all the input data has been collected and grouped together called Batched Generally data is accumulated for a certain period of time or unitl a certain quantity. - Ads Response time is not critical. Need to process large volumn of data. Computer efficiency is more important than response time. - Dis Time between recording and processing of source document is long Rereen normally required if errors are encountered. Data is not current. Error correction is more difficult. Question 2. Online Processing System - Def Inputs data enters the computer directly as soon as it is being transacted. There information will be processed immediately and updated into the master file. - Ads Enter availability of information for decision making. More accurate data capture. .