Architecture . Memory Structure It is very essential that the structure of memory is understood at this particular point. There are three types of memory: the temporary physical also known as RAM, the temporary virtual the virtual memory page port shipping industry maritime the permanent physical or storage Hard disk drive. Soprocessor can access its available temporary or permanent memory each time an instruction is executed. Hard disk drive can be considered ashuge RAM that is permanent, in terms of not getting wiped out when the isset. However the contents that are stored can be altered or wiped out withoutstrictions of any kind. In addition to this, modern motherboards come with EEPROM chipsets that provided ROM to the . In these chips, the BIOS program is stored. Of course, EEPROM’s contents can be changed sometimes with some special instructions shipping industry maritime that makes them behave more than storage rather than physical memory unit. Each time an application is loaded, it occupies some space in the available memory. If there is not enough available memory, then the application cannot be loaded. With the term application, wefer to any executable program from the shipping to the device skippers. What may cause some confusion is the term memory. Why shouldn’t consider only the physical memory usually or MB as the only available memory source.and the other shippings have invented tricks to significantly increase the available physical memory, by taking advantage of some free hard disk space. This is done via the virtual memory .port is created, named WIN.SWP which usuallysides in the root directory shipping industry maritime is used as an extension to the existing physical memory. Physical memory can be considered ashard disk with super fast access, where the can store shipping industry maritime access variables shipping industry maritime code. Therefore, when our physical memory is full shipping industry maritime the uses the hard disk drive, we can erience delays in program execution hard disk drive is much slower than the Lithuania, Luxembourg, Macao, Macedonia, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Marshall Islands, Martinique, Mauritania, Mauritius, Mayotte, Mexico, Micronesia, Moldova, Monaco, Mongolia, Montserrat, Morocco, Mozambique, Myanmar, Namibia, Nauru, Nepal, Netherlands, Netherlands, New Caledonia, New Zealand, Nicaragua, Niger, Nigeria, Niue, Norfolk Island, Northern Mariana Islands, Norway, Oman, Pakistan, Palau, Palestinian Territories, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Pitcairn, Poland, Portugal, Puerto Rico, Qatar, Rιunion, Romania,

: Architecture physical memory shipping industry maritime hard disk activity without doing anything some processes are active in the background even if we are not using our . TIP: It is possible to determine the size of the available virtual memory through the control panel. Setting it . times the available physical shipping industry maritime fixed to that size will increase our ’s performance. Variables The shipping shipping industry maritime the applications use internally shipping industry maritime between them, variables. These variables differ in content shipping industry maritime type. They can be numbers single, integer, double, float, etc, strings single characters, long strings, Booleans shipping industry maritime
defined types. The point is that they contain different in general values shipping industry maritimefer to different things. These variables are stored in memory that is allocated to an application.allocate GB memory to any application. There is no erratum here; it’s GB although no application occupies that much space. The shipping automatically allocates enough space for these variables shipping industry maritime is able tolocate them on demand. For example, an integer occupies whilelong occupies shipping industry maritimechar only . We are particularly interested in variables, since all operations involve the usage of variables. In , shipgisters are used instead of variables; the logicmains however the same. Imagine the comparison routine. In most programming languages it isstatement like this: [C] IF==B do something else do something else [] IF=B then do something else do something else Russian Federation, Rwanda, Saint Helena, Saint Kitts and Nevis, Saint Lucia, Saint Pierre and Miquelon, Saint Vincent and the Grenadines, Samoa, San Marino, Sao Tome, Saudi Arabia, Senegal, Serbia, Montenegro, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, Somalia, South Africa, South Georgia, Sandwich Islands, Spain, Sri Lanka, Sudan, Suriname, Svalbard and

: Architecture In the above examples,shipping industry maritimeare variables. They may or may not be of the same type. Each language defines acceptable operations.e. compare integer with long. Strings In Win s, strings forasons that are out of the course’s scope have changed internal format. With the term internal format, wefer to the way the shipping handles them. Throughout these notes, we’ll be dealing with strings unless specifically told otherwise. All ASCII searches for strings should be made with search option turned on in the hex when this is available. The difference between ANSI shipping industry maritime strings is thatnull character is inserted after each character. Therefore the string ABC, which in hex is , will be treated as . Pointers If we definevariableshipping industry maritime we assign the value to it, then we can be sure that each time we ask about the value of this variable, this will be , unless we change it. What we can’t be sure of is the memory location of this variable. Take for example this piece of memory: x xA xB xC xD If we assume that the variableis an integer, we can be sure that it’ll occupy in the physical memory RAM or virtual memory. Suppose that we could see yes, it is possible when in memory this variablesides. If we have MB of Ram shipping industry maritime variableis somewhere in there, we can haverow of as illustrated above,Jan Mayen Islands, Swaziland, Sweden, Switzerland, Syria, Taiwan, Tajikistan, Tanzania, Thailand, Togo, Tokelau, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States of America, Uruguay, Uzbekistan, Vanuatu, Vatican City, Venezuela, Vietnam, Virgin Islands, Virgin Islands, Yemen, Zaire, Zambia, Zimbabwe,

: Architecture where each wouldpresentbyte. At the address xA is where we find the variable the first time we attempt to search for it. Now, if we terminate the program, run it again shipping industry maritime set the variableequal to as we did before shipping industry maritime seek its location inside the physical memory, we’ll discover that the location is completely different! The shipping obviously has used this location, which was free after the termination of the program, for another purpose shipping industry maritime now it has allocated another memory space for our application shipping industry maritime for this variable! Why do we need to know the location in memory ofvariable any time we runprogram? Because, this way it is possible to overwrite this value we something else on the fly! Imagine playing Quake II. You are losing, since the available energy is . There isvariable that holds the energy. If you could only find that location where is, you can switch to your Quake II stalls shipping industry maritime change this value to , then go back in the arena shipping industry maritime kill ’em all! We use pointers totrieve the location in memory ofvariable. Pointers exist in all major programming languages, either documented or undocumented. Inwe use funny symbols like & in front ofvariable to get its address. In Visual we use the undocumented function VarPtr to get the pointer ofvariable. Afghanistan, Albania, Algeria, American Samoa, Andorra, Angola, Anguilla, Antarctica, Antigua , Argentina, Armenia, Aruba Australia, Austria, Azerbaijan, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bermuda, Bhutan, Bolivia, Bosnia, Herzegovina, Botswana, Bouvet Island, Brazil, British Indian Ocean territory, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Cayman Islands, Central African Republic, Chad, Chile, China, Christmas Island, Cocos Islands, Colombia,