Visitor Management System Singapore
Visitor Management A memory that would hold both programs and data, the so-called stored program concept. This solved the difficult problem of rewiring the control panels for changing programs on the ENIAC.
Visitor Management Binary processing of data. This simplified the design of the computer and allowed the use of binary memory for both instructions and data. It also recognized the natural relationship between the ON/OFF nature of switches and calculation in the binary number system, using Boolean logic The CPU was to include ALU, memory, and CU components. The control unit read instructions from memory and executed them. A method of handling input/output through
Visitor Management the control unit was also established. The instruction set contained instructions representing all the essential features of a modern computer. In other words, von Neumann’s machine contained every major feature considered essential to modern computer architecture. Modern computer architecture is still referred to as von Neumann architecture
Visitor Management Due to political intrigue and controversy, two different versions of von Neumann’s architecture were designed and built, EDVAC at the University of Pennsylvania and IAS at the Princeton University Institute for Advanced Studies (hence the unusual name). Both machines were completed in 1951–1952. The success of EDVAC and IAS led to the development of many offspring, mostly with odd names, and to several commercial computers, including the first IBM computers
Visitor Management At this point, von Neumann’s architecture was firmly established. It remains the prevalent standard to this day and provides the foundation for the remainder of the material in this book. Although there have been significant advances in technology, and improvements in design that have resulted, today’s designs still reflect the work done prior to 1951 on ABC, ENIAC, EDVAC, and IAS.
Visitor Management All of these early electronic computers relied on the electronic vacuum tube for their operation. Vacuum tubes were bulky, made of glass, fragile, short-lived, and required large amounts of power to operate. Vacuum tubes require an internal electric heater to function, and the heaters tend to fail quickly, resulting in what was known as a ‘‘burned out’’ tube. Furthermore, the heat generated by the large number of tubes used in a computer required a massive forced-air or water-cooling system. A report reprinted by computer historian James Cortada [CORT87] states that the average error-free operating time for ENIAC was only 5.6 hours. Such bulky, maintenance-requiring systems could not have attained the prevalence that computers have in our society
Visitor Management The technological breakthrough that made possible today’s small, sophisticated computers was the invention of the transistor and, subsequently, the integration of transistors and other electronic components with the development of the integrated circuit
Visitor Management The invention of the integrated circuit led to smaller, faster, more powerful computers as well as a new, compact, inexpensive form of memory, RAM. Although many of these computers played an important role in the evolution of today’s computers, two specific developments stand out from the rest: (1) development of the first widely accepted personal computer, by IBM in 1981, and (2) design of the Intel 8008 microprocessor, predecessor to the x86 CPU family, in 1972. The impact of these two developments is felt to this day
Visitor Management Companies have developed better ways of moving data between different parts of the computer, better ways of handling memory, and methods for increasing the speed of instruction execution. There is a lot more processing power in today’s personal computer than there was in the largest mainframe computer in the 1970s. Nonetheless, the basic architecture of today’s machines is remarkably similar to that developed in the 1940s
Visitor Management Given how easy it is to communicate with computers today, it is hard to picture a time when the user had to do everything by hand, one step at a time. We take it for granted that we can type commands at a keyboard or move a mouse and launch programs, copy files, send text to a printer, and perform myriad other computer tasks. We power up and bootstrap our systems by pressing a switch.
Visitor Management It was not always this way. Early computers had no operating systems. The user, who was also the programmer, entered a program by setting it, one word at a time, with switches on the front panel, one switch per bit, or by plugging wires into a patch panel that resembled a cribbage board. Not a pleasant operation! Needless to say, early computers were single-user systems. Much of the computer’s time was tied up with this primitive form of program and data entry. In fact, as late as the mid-1970s, there were still vendors producing computer systems with no operating system and computer hardware that was still bootstrapped by entering the bootstrap program one instruction at a time into switches on the front panel of the computer
Visitor Management The history of system software, particularly operating systems, is much less well defined than that of hardware. According to Cortada
Visitor Management Without more sophisticated operating systems, scientists would not have been able to take full advantage of the power of the transistor and later of the [microprocessor] chip in building the computers known today. Yet their contribution to the overall evolution of digital computers has been overlooked by historians of data processing