vb复习（VB review）.docVIP

vb复习（VB review） Book One Information is useful data for human beings Data is the representation of information, and information is the meaning expressed by data The characteristics of information: authenticity, knowledge, purpose, sharing, infinity, temporality Information processing: collection, processing (core), storage, delivery, and Application 3C technology, computer, communication, control 1946, the first ENIAC The characteristics of information processing are: fast processing speed, large information storage ability, automatic processing, and logical judgment The calculation precision is high and the versatility is strong Moores Law: the degree of integration of a single block of integrated circuits is doubled on average every 18~24 months Common number: ten (D) two (B) eight (Q) sixteen (H) Ex: N decimal to decimal Ten - two integer part, in addition to two from bottom to top take out, the decimal part in addition to two from top to bottom to take over, the two part of the connection Two - eight, each three bit binary is represented by an octal digit (CF sixteen) Operations: arithmetic, logic The data type data unsigned integer unsigned integer (original code, complement, complement) * plus the original code, complement, complement the same Negative one, the sign bit is 1, the rest to take anti complement, the complement of a The complement of 0 represents uniqueness CPU (arithmetic unit, controller) Hardware host Computer system memory Peripheral Software system, application The five basic components of a von Neumann computer: ALU, memory, controller, and I / O device CPU can access only memory directly, and memory is directly connected with CPU, which is volatile register Catch memory Main memory ROM. RAM External storage Backing memory (tape, CD) 1Byte=8bit An instruction consisting of operands and operands The unit of computer speed MIPS: 1 million fixed-point instructions / sec MFLOPS: one million negative count / sec The main performance index of CPU