It may be argued that this brief introduction to hardware is unnecessary. The computer  repair miami has become a utilitarian device, to be used by people who are nontechnical the same way that a car can be used by all people, without any need to understand the workings of the engine, the various support systems, and the energy management of the car. This is true, but only partially. Consider a hybrid car, such as the Toyota Prius. It is designed to be just like any other car: drivable without the intricate understanding needed to grasp the concept of the synergy drive of a car where multiple modes of propulsion cooperate to optimize the energy usage of this essentially electric car. However, the actual energy consumption differs between drivers. Those who understand the working of this car will get better energy efficiency than the casual driver in our experience sometimes as high as a 16% difference. We argue that the same concept is true for software. Understanding the underlying machinery the computer system enables more efficient software development. This may not be important for small tasks, but it may be crucial for very large ones. A digital computer and we limit ourselves to these only is a device that has three main parts: at least one processing unit, called the central processing unit or CPU, at least one memory unit, and a control unit. A computer system has, in addition to a computer, a set of peripheral devices that can be roughly divided into three categories: user interface devices, mass storage devices, and communication devices. Most of the computers today are based on the Von Neumann model of computing, which is as follows: the memory holds computer programs and all the data values that are necessary for the computer program. A computer program is built from instructions that are executed in a logical sequence. The computer operates by causing the control unit to select an instruction from memory. That instruction causes the control unit to fetch data from the memory to the processing unit. There may be one data item, more than one, or none. The processing unit then performs the function implied by the instruction, and the control unit saves the result in memory and selects the next instruction to be fetched from memory. This is the gist of the Von Neumann model. In reality, there are various types of memory, very complex control units, and optionally multiple processing units that can deal with many instructions in parallel. There are many other optimizations, but no matter how complex, logically, there is a strict serialization imposed by this model, and the instructions seem to be performing serially. The memory stores all its contents, be it instructions or data, as numbers. The representation of numbers that we use is called the radix or positional representation. To create such a representation, we choose a radix sometimes called the base of the representation, say, r. We select r symbols that have the values of 0 through r–1. Numbers are then represented by a sequence of these symbols. We know that each position in the sequence has an ordinal (sequence position number), counted from right to left. Thus, the rightmost position has the ordinal 0, the next one has ordinal 1, and so on. The value of the represented number is then computed by multiplying the value of the symbol in position n by the weight or the factor of that position, that is, rn, and adding all values together. In our familiar decimal system, the radix is 10. The 10 symbols that we use are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. We call these symbols digits, carrying the values from zero to r-1 which is 9. For example, to see what is represented by a three-digit number, say, 123, we compute the weight of each position. A computer system has two types of memory: short-term random access memory RAM that is fast but limited usually measured in gigabytes with access times in nanoseconds and long-term that is thousands of times slower but far more vast often measured in terabytes with access times in milliseconds. Additionally, a computer has a few small brains or central processing units CPUs that execute instructions, input and output mediums, and a network connection to support the exchange of information between machines,the second position has the factor 101, which is 10, and the third has the factor 102, which is 100. The value of the number is thus 3 × 1 + 2 × 10 + 1 × 100 = 123, as expected. Assume now radix 4 that is, the base of our positional system is 4, usually called the quaternary system. We need four symbols that we choose to be 0, 1, 2, and 3, with the obvious values.