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83-688: System design began in 1979 in Cupertino, California at Olivetti's Advanced Technology Center. When announced on March 31, 1982, it was probably the first 16-bit personal computer in Europe with an expected price range of US$ 3,000-6,000. InfoWorld magazine saw the M20 as an "answer to Tandy's Model 16 , the IBM Personal Computer and the Apple III "; Olivetti itself compared its computer to

166-721: A branch line track up to the Lehigh Permanente Cement Plant from the mainline at San Jose Diridon Station . It is, however, strictly for the quarry and very little to no non-quarry traffic runs there. There is no commuter rail or light rail service in the city. Caltrain commuter rail runs through the cities to the north and east, and the Santa Clara Valley Transportation Authority (VTA)'s Mountain View – Winchester light rail line runs to Campbell , California to

249-422: A computer to appear as if it may have more memory available than physically present, thereby allowing multiple processes to share it. In some operating systems , e.g. Burroughs/Unisys MCP , and OS/360 and successors , memory is managed by the operating system. In other operating systems, e.g. Unix-like operating systems, memory is managed at the application level. Memory management within an address space

332-443: A female householder with no husband present, 581 (2.9%) had a male householder with no wife present. There were 378 (1.9%) unmarried opposite-sex partnerships , and 89 (0.4%) same-sex married couples or partnerships . 3,544 households (17.6%) were made up of individuals, and 1,612 (8.0%) had someone living alone who was 65 years of age or older. The average household size was 2.87. There were 15,776 families (78.2% of all households);

415-640: A few older roads towards the Monta Vista High School area are a little dim. Dedicated on April 30, 2009, Cupertino opened the Mary Avenue Bicycle Footbridge , the first cable-stayed bicycle-pedestrian bridge over a California freeway. This bridge connects the north and the south sections of the Stevens Creek Trail. The cost of the bridge project was $ 14,800,000. The Union Pacific Railroad operates

498-466: A list of free cache slots. Constructing an object will use any one of the free cache slots and destructing an object will add a slot back to the free cache slot list. This technique alleviates memory fragmentation and is efficient as there is no need to search for a suitable portion of memory, as any open slot will suffice. Many Unix-like systems as well as Microsoft Windows implement a function called alloca for dynamically allocating stack memory in

581-458: A multiple of 2 KB in size—the size of an area protected by a protection key. Subpools are numbered 0–255. Within a region subpools are assigned either the job's storage protection or the supervisor's key, key 0. Subpools 0–127 receive the job's key. Initially only subpool zero is created, and all user storage requests are satisfied from subpool 0, unless another is specified in the memory request. Subpools 250–255 are created by memory requests by

664-893: A new IBM PC-compatible computer, the Olivetti M24 , running MS-DOS as a "complement" to the Olivetti M20. Olivetti sold around 50,000 M20 computers in the first year of production. Only a few games were released for the system. M20 uses Zilog Z8001 4 MHz CPU and 128 KB RAM, which can be expanded up to 512 KB by three 128 KB memory boards. Keyboard, motherboard and disk drives are contained in all-in-one unit with separate monitor. The computer has also parallel ( IEEE-488 ) and serial port ( RS-232-C ). Standard configuration includes two 5 + 1 ⁄ 4 -inch 320 KB floppy disk drives (286 KB formatted capacity). Optional were 160 KB or 640 KB (compatible with 320 KB disks) drives or 5 + 1 ⁄ 4 -inch hard disk in place of one of

747-426: A particular size are kept in a sorted linked list or tree and all new blocks that are formed during allocation are added to their respective memory pools for later use. If a smaller size is requested than is available, the smallest available size is selected and split. One of the resulting parts is selected, and the process repeats until the request is complete. When a block is allocated, the allocator will start with

830-489: A population of 58,302. The population density was 5,179.1 inhabitants per square mile (1,999.7/km ). The racial makeup of Cupertino was 18,270 (31.3%) White, 344 (0.6%) Black American, 117 (0.2%) Native American, 36,895 (63.3%) Asian (28.1% Chinese, 22.6% Indian, 4.6% Korean, 3.3% Japanese, 1.3% Vietnamese), 54 (0.1%) Pacific Islander, 670 (1.1%) from other races, and 1,952 (3.3%) from two or more races. Hispanic of any race were 2,113 persons (3.6%); 2.4% of Cupertino's population

913-444: A presentation to Cupertino City Council, detailing the architectural design of the new building and its environs. The campus houses 13,000 employees in one central four-story circular building surrounded by extensive landscaping, with parking mainly underground and the rest centralized in a parking structure. In 2002, Cupertino had a labor force of 25,780 with an unemployment rate of 4.5%. The unemployment rate for Santa Clara County as

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996-408: A private school. Cupertino is known for its high-achieving primary and secondary school students. For example, Murdock-Portal Elementary and Faria Elementary School are tied for highest score for elementary public school in the state of California , per California 2013 API test scores. As of 2013, John F. Kennedy Middle School is the best public middle school in the state, and Lawson Middle School

1079-483: A shared ride on demand through a smartphone app. The transit network serves the entire City of Cupertino with a satellite zone surrounding the Sunnyvale Caltrain station for commuters. Cupertino is twinned with: Cupertino also has friendly relations with: Memory management Memory management (also dynamic memory management , dynamic storage allocation , or dynamic memory allocation )

1162-547: A strategy for automatically detecting memory allocated to objects that are no longer usable in a program, and returning that allocated memory to a pool of free memory locations. This method is in contrast to "manual" memory management where a programmer explicitly codes memory requests and memory releases in the program. While automatic garbage collection has the advantages of reducing programmer workload and preventing certain kinds of memory allocation bugs, garbage collection does require memory resources of its own, and can compete with

1245-456: A way similar to the heap-based malloc . A compiler typically translates it to inlined instructions manipulating the stack pointer. Although there is no need of manually freeing memory allocated this way as it is automatically freed when the function that called alloca returns, there exists a risk of overflow. And since alloca is an ad hoc expansion seen in many systems but never in POSIX or

1328-612: A whole was 8.4%. One of the major employers in the area is the aggregate rock quarry and cement plant in the foothills to the west of Cupertino, the Permanente Quarry . Owned and operated by Lehigh Southwest Cement, it was founded by Henry J. Kaiser as the Kaiser Permanente Cement Plant in 1939. It provided the majority of the cement used in the construction of the Shasta Dam . It supplied

1411-525: Is a supervisor function. Storage is requested using the GETMAIN macro and freed using the FREEMAIN macro, which result in a call to the supervisor ( SVC ) to perform the operation. In OS/360 the details vary depending on how the system is generated , e.g., for PCP , MFT , MVT . In OS/360 MVT, suballocation within a job's region or the shared System Queue Area (SQA) is based on subpools , areas

1494-670: Is a city in Santa Clara County, California , United States, directly west of San Jose on the western edge of the Santa Clara Valley with portions extending into the foothills of the Santa Cruz Mountains . The population was 60,381 as of the 2020 census . The city is widely known for being the home of Apple Inc. , headquartered within the city at Apple Park . Named for a local creek by Spanish explorer Juan Bautista de Anza 's cartographer bearing

1577-415: Is a form of resource management applied to computer memory . The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase

1660-404: Is a point in execution where all of those chunks are known to be no longer valid. For example, in a web service, after each request the web service no longer needs any of the memory allocated during the execution of the request. Therefore, rather than keeping track of whether or not memory is currently being referenced, the memory is allocated according to the request or lifecycle stage with which it

1743-443: Is associated. When that request or stage has passed, all associated memory is deallocated simultaneously. Virtual memory is a method of decoupling the memory organization from the physical hardware. The applications operate on memory via virtual addresses . Each attempt by the application to access a particular virtual memory address results in the virtual memory address being translated to an actual physical address . In this way

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1826-610: Is available at San Jose International Airport in San Jose. The closest general aviation airport is in Palo Alto ; it is known as Palo Alto Airport of Santa Clara County . The City of Cupertino partnered with Via Transportation in October 2019 to launch a new on-demand public transportation network. Unlike traditional bus networks that rely on routes and schedules, the new microtransit service called Via allows riders to hail

1909-455: Is generally categorized as either manual memory management or automatic memory management. The task of fulfilling an allocation request consists of locating a block of unused memory of sufficient size. Memory requests are satisfied by allocating portions from a large pool of memory called the heap or free store . At any given time, some parts of the heap are in use, while some are "free" (unused) and thus available for future allocations. In

1992-600: Is home to De Anza College , one of the two community colleges in the Foothill–De Anza Community College District . The University of San Francisco has satellite campuses in Cupertino. The city is served by an interconnected road system. Two freeways , State Route 85 and Interstate 280 , intersect in Cupertino, with multi-lane boulevards with landscaped medians and traffic lights at all major intersections. Almost all streets have sidewalks;

2075-432: Is known for its high real estate prices. 2010 saw HP consolidate its Bay Area workforce in its hometown of Palo Alto , and the company proceeded to close its campus within Cupertino. The city estimated that the closure of the campus would lead to 3,000 to 3,500 employees being relocated. Apple eventually bought the campus site from HP for an undisclosed price and prepared to use the land to build Apple Park . Cupertino

2158-475: Is located at 37°19′23″N 122°01′55″W  /  37.32306°N 122.03194°W  / 37.32306; -122.03194 (37.3229978, −122.0321823), at the southern end of the San Francisco Bay . The eastern part of the city, located in the Santa Clara Valley , is flat, while the western part of the city slopes into the Santa Cruz Mountains . Cupertino borders San Jose and Santa Clara to

2241-409: Is located there in a modern circular complex. It is a 150-acre (610,000 m ) campus between Interstate 280, N Wolfe Rd, E Homestead Rd and along Tantau Ave one mile east of the old campus. The nine properties (50-acre (0.2 km )) south of Pruneridge Avenue were bought in 2006, the property (100-acre (0.4 km ) north of it in 2010 (from Hewlett-Packard ). On June 7, 2011, Steve Jobs gave

2324-407: Is notified when the area it is pointing to is no longer valid) or by combining reference counting and garbage collection together. A memory pool is a technique of automatically deallocating memory based on the state of the application, such as the lifecycle of a request or transaction. The idea is that many applications execute large chunks of code which may generate memory allocations, but that there

2407-400: Is of Mexican ancestry. The census reported that 57,965 people (99.4% of the population) lived in households, 61 (0.1%) lived in non-institutionalized group quarters, and 276 (0.5%) were institutionalized. There were 20,181 households, out of which 9,539 (47.3%) had children under the age of 18 living in them, 13,802 (68.4%) were opposite-sex married couples living together, 1,393 (6.9%) had

2490-533: Is replaced today with the Cali Mill Plaza and City Hall. Back then, it was known as the West Side and was part of Fremont Township. The primary economic activity was fruit agriculture. Almost all of the land within Cupertino's present-day boundaries was covered by prune , plum , apricot , and cherry orchards. A winery on Montebello Ridge overlooking the Cupertino valley region was also in operation by

2573-790: Is the third best in the state. Furthermore, Monta Vista High School is ranked number 23 out of all the public high schools in the nation. Primary (K-8) public schools are organized into the Cupertino Union School District , while the Fremont Union High School District is responsible for high school students (except for a tiny portion of the northeast corner of the city which belongs to the Santa Clara Unified School District ). Cupertino High School and its feeder school, Hyde Middle School , are located in

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2656-614: The California State Legislature , Cupertino is in the 15th Senate District , represented by Democrat Dave Cortese , and in the 26th Assembly District , represented by Democrat Evan Low . In the United States House of Representatives , Cupertino is in California's 17th congressional district , represented by Democrat Ro Khanna . Santa Clara County Library operates

2739-536: The Rancho Rinconada section of Cupertino, while Monta Vista High School and its feeder, Kennedy Middle School , are in the Monta Vista neighborhood in the western half of Cupertino. Lawson Middle School feeds mostly Cupertino and Monta Vista High. In addition, Homestead High School is located in the northwestern portion of Cupertino, along the city border with neighboring Sunnyvale . Cupertino

2822-738: The United States Census Bureau , the city has a total area of 11.3 square miles (29 km ), 99.99% of it land and 0.01% of it water. Cupertino has a warm-summer Mediterranean climate ( Csb under the Köppen climate classification system), with warm to hot, dry summers and cool, wet winters. Cupertino is made up of numerous subdivisions, most of them developed since the 1960s. Most of Cupertino's contemporary properties were developed around 1960. The area between Stevens Creek Boulevard , Miller Avenue, Bollinger Road, and Lawrence Expressway contains 224 Eichler homes, built during

2905-413: The overheads involved for a variety of allocators. The lowest average instruction path length required to allocate a single memory slot was 52 (as measured with an instruction level profiler on a variety of software). Since the precise location of the allocation is not known in advance, the memory is accessed indirectly, usually through a pointer reference . The specific algorithm used to organize

2988-418: The "Change Key" system utility. Instead of standard function keys , user defined special functions are invoked by pressing orange-colored ⌘ Command or light-blue-colored Control key along with another key (creates 24 user-definable function keys). Numeric keypad serves also as cursor controls . PCOS (Professional Computer Operating System) is a single-user, single-tasking operating system . It

3071-494: The 1950s. Two of the newest parts of Cupertino are among its oldest housing tracts. Monta Vista and Rancho Rinconada were developed outside of the city's boundaries in the 1950s and before. Rancho Rinconada was annexed in 1999 and the last part of Monta Vista was annexed in 2004. The neighborhood of Seven Springs is at the southwestern tip of Cupertino and was developed in the late 1980s. The newest and most northwestern neighborhood, Oak Valley, borders Rancho San Antonio Park and

3154-540: The 6 million barrels (950,000 m ) of cement over a nine-mile (14 km)-long conveyor system. The cement plant is the sole reason for the railroad line that runs through the city. According to the city's 2020–21 Comprehensive Annual Financial Report, the top employers in the city are: Cupertino was incorporated in 1955. The highest body in the city government – the City Council – is made up of five members who serve overlapping, four-year terms. The council elects

3237-482: The C language, the function which allocates memory from the heap is called malloc and the function which takes previously allocated memory and marks it as "free" (to be used by future allocations) is called free . Several issues complicate the implementation, such as external fragmentation , which arises when there are many small gaps between allocated memory blocks, which invalidates their use for an allocation request. The allocator's metadata can also inflate

3320-454: The C standard, its behavior in case of a stack overflow is undefined. A safer version of alloca called _malloca , which reports errors, exists on Microsoft Windows. It requires the use of _freea . gnulib provides an equivalent interface, albeit instead of throwing an SEH exception on overflow, it delegates to malloc when an overlarge size is detected. A similar feature can be emulated using manual accounting and size-checking, such as in

3403-491: The California History Center. De Anza College had 16,335 students as of 2022. By the 1980s, Apple Inc. and Hewlett-Packard were the primary technology companies with major presences in Cupertino, with Housing developments were rapidly constructed in the following years as developers created neighborhoods, including Fairgrove, Garden Gate, Monta Vista , Seven Springs, and other developments. The city

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3486-576: The Cupertino Library, which is located adjacent to city hall. The library, which was redesigned and rebuilt in 2004, is the busiest branch in the Santa Clara County Library system, with about 3 million items circulated annually. The San Francisco Japanese School , a weekend educational program for Japanese citizen children living abroad , holds classes at J.F. Kennedy Middle School in Cupertino, as well as Harker ,

3569-503: The IBM PC, Sirius Victor , Commodore 8000 and Apple II in television advertising. Although the computer was initially well received, its use of a non-standard OS (Olivetti's proprietary PCOS) and CPU (Zilog Z8001) proved to be its most serious limitations. The first major software package was a word processor by SofSys called Executive Secretary , followed later by another word processor, OliWord , and business software, Olibiz . There

3652-535: The Leonard, Lester, Craft, and Orlando families. A neighborhood outdoor shopping center and, much later, the enclosed Vallco Fashion Park , briefly renamed Cupertino Square, were also developed. De Anza College opened in 1967. The college, named for Juan Bautista De Anza , occupies a 112-acre (0.45 km ) site that was the location of a winery built at the turn of the 20th century, called Beaulieu by its owners, Charles and Ella Baldwin. Their mansion has now become

3735-680: The MCP OS (enabled by the UNSAFE block directive in NEWP ). Donald Knuth describes a similar system in Section 2.5 ‘Dynamic Storage Allocation’ of ‘Fundamental Algorithms’ . IBM System/360 does not support virtual memory. Memory isolation of jobs is optionally accomplished using protection keys , assigning storage for each job a different key, 0 for the supervisor or 1–15. Memory management in OS/360

3818-456: The Z8000 CPU. PCOS can protect by password volumes (disks), individual files and BASIC programs (against listing/editing/copying). Standard OS configuration includes BASIC interpreter, other programming languages ( Assembler and PASCAL ) are optional. Example PCOS commands: Cupertino, California Cupertino ( / ˌ k uː p ər ˈ t iː n oʊ / KOOP -ər- TEEN -oh )

3901-406: The addition of virtual memory enables granular control over memory systems and methods of access. In virtual memory systems the operating system limits how a process can access the memory. This feature, called memory protection , can be used to disallow a process to read or write to memory that is not allocated to it, preventing malicious or malfunctioning code in one program from interfering with

3984-443: The application program for processor time. Reference counting is a strategy for detecting that memory is no longer usable by a program by maintaining a counter for how many independent pointers point to the memory. Whenever a new pointer points to a piece of memory, the programmer is supposed to increase the counter. When the pointer changes where it points, or when the pointer is no longer pointing to any area or has itself been freed,

4067-634: The average family size was 3.28. The population was spread out, with 16,075 people (27.6%) under the age of 18, 3,281 people (5.6%) aged 18 to 24, 15,621 people (26.8%) aged 25 to 44, 16,044 people (27.5%) aged 45 to 64, and 7,281 people (12.5%) who were 65 years of age or older. The median age was 39.9 years. For every 100 females, there were 97.4 males. For every 100 females age 18 and over, there were 94.6 males. There were 21,027 housing units at an average density of 1,867.9 per square mile (721.2/km ), of which 12,627 (62.6%) were owner-occupied, and 7,554 (37.4%) were occupied by renters. The homeowner vacancy rate

4150-428: The computer can display 8 colors. When using only one additional memory board, only 4 colors form 8 color palette are available. All graphics is pixel-generated (there is no specific text mode ), text characters use resolution 64 characters per 16 rows (or 80 characters per 25 rows). Keyboard lacks Delete , Tab ↹ and ← Backspace keys - their function can be mapped on S1 or s2 special keys by

4233-483: The counter should decrease. When the counter drops to zero, the memory should be considered unused and freed. Some reference counting systems require programmer involvement and some are implemented automatically by the compiler. A disadvantage of reference counting is that circular references can develop which cause a memory leak to occur. This can be mitigated by either adding the concept of a "weak reference" (a reference that does not participate in reference counting, but

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4316-516: The earliest roots of Silicon Valley developing near Cupertino. By the 1960s, office parks were being built and technology companies were setting up shop in the city, most notably Apple and Hewlett-Packard . Today, Cupertino remains a cornerstone of Silicon Valley with its residents making a median household income of just under $ 200,000 a year. The economy is dominated by technology companies, both large ones like Apple, as well as medium-sized companies and various Silicon Valley startups. Cupertino

4399-479: The east, Saratoga to the south, Sunnyvale and Los Altos to the north, and Loyola to the northwest. Several streams run through Cupertino on their way to south San Francisco Bay , including (from north to south): Permanente Creek , Stevens Creek , San Tomas Aquino Creek and its Smith Creek , the Regnart Creek and Prospect Creek tributaries of Calabazas Creek , and Saratoga Creek . According to

4482-444: The effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of RAM using paging or swapping to secondary storage . The quality of the virtual memory manager can have an extensive effect on overall system performance . The system allows

4565-549: The few exceptions are in unincorporated pockets at the city's edges, which are maintained directly by Santa Clara County. Cupertino has bike lanes on many of its boulevards, and has an extension of the Stevens Creek Trail through McClellan Ranch Park and Blackberry Farm . Bicycle traffic is heavy usually around morning and noon times around DeAnza College. The VTA has buses running through Cupertino at major arteries. Cupertino's main streets are well lit, while

4648-456: The floppy disk drives (9.2 MB formatted capacity). Motherboard has two expansion slots intended for the hard disk controller board, additional parallel interface, twin serial interface or Corvus Omninet LAN card. This slot is also used by the APB 1086 CPU card. M20 provides 512 × 256 display resolution on 12-inch monochrome or color monitor. With memory expanded by two 32 KB memory boards,

4731-488: The former name for the region, which was West Side . In the 19th century, Cupertino was a small rural village at the crossroads of Stevens Creek Road and Saratoga-Mountain View Road (also known locally as Highway 9; later Saratoga–Sunnyvale Road, and then renamed to De Anza Boulevard within Cupertino city limits). For decades, the intersection was dominated on the southeast corner by the R. Cali Brothers Feed Mill, which

4814-497: The hardware resource). The virtual memory extends physical memory by using extra space on a peripheral device, usually disk. The memory subsystem is responsible for moving code and data between main and virtual memory in a process known as overlaying. Burroughs was the first commercial implementation of virtual memory (although developed at Manchester University for the Ferranti Atlas computer) and integrated virtual memory with

4897-647: The high $ 2 millions, mid-size homes start from the mid $ 3 millions, and larger executive homes start from mid $ 4 millions and can go up to as much as $ 7 million, as of the 2022 peak. However, townhouses and condos with similar square footage are relatively less expensive, owing mainly to negligible lot sizes and the many common walls and areas. 63 percent of Cupertino's population was of Asian ancestry in 2010, compared to 32 percent in Santa Clara County overall. Money ' s Best Places to Live, "America's best small towns", ranked Cupertino as #27 in 2012,

4980-424: The late 19th century. Soon railroads, electric railways, and dirt roads traversed the West Side farmlands. Monta Vista , Cupertino's first housing tract, was developed in the mid-20th century as a result of the electric railway's construction. After World War II , a population and suburban housing boom dramatically shifted the demographics and economy of the Santa Clara Valley , as the "Valley of Heart's Delight"

5063-691: The mayor and vice-mayor for a term of one year. The city does not have its own charter. Instead, it is a General Law city, which follows provisions and requirements for cities established by the state of California. Cupertino contracts with the Santa Clara County Sheriff's Office and the Santa Clara County Fire Department for public safety services. The Cupertino Library is part of the Santa Clara County Library System. In

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5146-452: The memory area and allocate and deallocate chunks is interlinked with the kernel , and may use any of the following methods: Fixed-size blocks allocation, also called memory pool allocation, uses a free list of fixed-size blocks of memory (often all of the same size). This works well for simple embedded systems where no large objects need to be allocated but suffers from fragmentation especially with long memory addresses. However, due to

5229-410: The moving of information between these two levels of memory. An operating system manages various resources in the computing system. The memory subsystem is the system element for managing memory. The memory subsystem combines the hardware memory resource and the MCP OS software that manages the resource. The memory subsystem manages the physical memory and the virtual memory of the system (both part of

5312-495: The name of Saint Joseph of Cupertino , Cupertino was officially incorporated in 1955, though it saw economic activity in the early 19th century. The area was originally an agricultural community producing prunes , apricots and cherries , with a winery joining the ranks by the 19th century. Cupertino grew immensely during the 1950s due to the suburban housing boom experienced after the Second World War , concurring with

5395-404: The operation of another. Even though the memory allocated for specific processes is normally isolated, processes sometimes need to be able to share information. Shared memory is one of the fastest techniques for inter-process communication . Memory is usually classified by access rate into primary storage and secondary storage . Memory management systems, among other operations, also handle

5478-545: The second highest in California. In 2014, Movoto Real Estate ranked Cupertino the seventh "happiest" suburb in the United States, ranking highly in the categories of income, safety, marriage, and education. In 2015, Forbes ranked Cupertino as one of the most educated places in the U.S. in respect to the percentage of high school and college graduates. The 2010 United States Census reported that Cupertino had

5561-486: The segment including address, length, machine type, and the p-bit or ‘presence’ bit which indicates whether the block is in main memory or needs to be loaded from the address given in the descriptor. Descriptors are essential in providing memory safety and security so that operations cannot overflow or underflow the referenced block (commonly known as buffer overflow). Descriptors themselves are protected control words that cannot be manipulated except for specific elements of

5644-423: The significantly reduced overhead, this method can substantially improve performance for objects that need frequent allocation and deallocation, and so it is often used in video games . In this system, memory is allocated into several pools of memory instead of just one, where each pool represents blocks of memory of a certain power of two in size, or blocks of some other convenient size progression. All blocks of

5727-432: The size of (individually) small allocations. This is often managed by chunking . The memory management system must track outstanding allocations to ensure that they do not overlap and that no memory is ever "lost" (i.e. that there are no " memory leaks "). The specific dynamic memory allocation algorithm implemented can impact performance significantly. A study conducted in 1994 by Digital Equipment Corporation illustrates

5810-421: The smallest sufficiently large block to avoid needlessly breaking blocks. When a block is freed, it is compared to its buddy. If they are both free, they are combined and placed in the correspondingly larger-sized buddy-block list. This memory allocation mechanism preallocates memory chunks suitable to fit objects of a certain type or size. These chunks are called caches and the allocator only has to keep track of

5893-553: The south. Bus service is also provided by VTA, and the prospect of a twenty-four-hour bus service on Stevens Creek Boulevard is being studied. Cupertino is also served by VTA's 523 Rapid bus, which runs from northern Sunnyvale and the Caltrain station to Downtown San Jose with limited stops and signal priority. Cupertino is landlocked and relies on the Port of Oakland for most oceangoing freight. Passenger and cargo air transportation

5976-414: The subpool. Memory is allocated by finding a free area of sufficient size, or by allocating additional blocks in the subpool, up to the region size of the job. It is possible to free all or part of an allocated memory area. The details for OS/VS1 are similar to those for MFT and for MVT; the details for OS/VS2 are similar to those for MVT, except that the page size is 4 KiB. For both OS/VS1 and OS/VS2

6059-399: The subroutine is called, and automatically releases that memory when the subroutine is exited. Special declarations may allow local variables to retain values between invocations of the procedure, or may allow local variables to be accessed by other subroutines. The automatic allocation of local variables makes recursion possible, to a depth limited by available memory. Garbage collection is

6142-466: The supervisor on behalf of the job. Most of these are assigned key 0, although a few get the key of the job. Subpool numbers are also relevant in MFT, although the details are much simpler. MFT uses fixed partitions redefinable by the operator instead of dynamic regions and PCP has only a single partition. Each subpool is mapped by a list of control blocks identifying allocated and free memory blocks within

6225-457: The system design of the B5000 from the start (in 1961) needing no external memory management unit (MMU). The memory subsystem is responsible for mapping logical requests for memory blocks to physical portions of memory (segments) which are found in the list of free segments. Each allocated block is managed by means of a segment descriptor, a special control word containing relevant metadata about

6308-426: The uses of alloca_account in glibc. The proper management of memory in an application is a difficult problem, and several different strategies for handling memory management have been devised. In many programming language implementations, the runtime environment for the program automatically allocates memory in the call stack for non-static local variables of a subroutine , called automatic variables , when

6391-405: Was 0.8%; the rental vacancy rate was 4.7%. 36,464 people (62.5% of the population) lived in owner-occupied dwelling units and 21,501 people (36.9%) lived in rental dwelling units. Cupertino is one of many cities that claim to be the "heart" of Silicon Valley , as many semiconductor and computer companies were founded there and in the surrounding areas. The new worldwide headquarters for Apple Inc.

6474-511: Was also Microsoft BASIC 5.2 with full support for the hardware's features. To alleviate a lack of applications, Olivetti sold a CP/M emulator for US$ 300 and distributed certain CP/M software packages ( dBase II and SuperCalc ) for their computer. Olivetti later introduced the "Alternate Processor Board" (APB 1086), based on an 8 MHz Intel 8086 CPU for compatibility with MS-DOS and CP/M-86 software. In January 1984, Olivetti introduced

6557-632: Was beginning to transform into " Silicon Valley ". In 1954, a rancher, Norman Nathanson, the Cupertino-Monta Vista Improvement Association, and the Fact Finding Committee, began a drive for incorporation. On September 27, 1955, voters approved the incorporation of the city of Cupertino (225 voted "yes" and 183 voted "no"). Cupertino officially became Santa Clara County's 13th city on October 10, 1955. A major milestone in Cupertino's development

6640-551: Was developed around the turn of the millennium. Cupertino is known for its high housing prices as the majority of residential properties are multimillion-dollar homes as of the priciest housing market peak of 2022, with the entry-point into a single-family home at around 2 million dollars in the Cupertino HS area, and the entry point at around 2.6 million dollars in the Monta Vista HS area. Many smaller homes start from

6723-415: Was named after Arroyo San José de Cupertino (now Stevens Creek ). The creek had been named by Spanish explorer Juan Bautista de Anza 's cartographer, who named it after Saint Joseph of Cupertino . The name Cupertino first became widely used when John T. Doyle, a San Francisco lawyer, and historian, named his winery on McClellan Road Cupertino . After the turn of the 20th century, Cupertino displaced

6806-414: Was the creation by some of the city's largest landowners of VALLCO Business and Industrial Park in the early 1960s. Of the 25 property owners, 17 decided to pool their land to form VALLCO Park, 6 sold to Varian Associates (property later sold to Hewlett-Packard ), and two opted for transplanting to farms elsewhere. The name VALLCO was derived from the names of the principal developers: Varian Associates and

6889-507: Was used on the Olivetti M20 and L1 computers. The first version (PCOS 1.0) supports 14 characters long filenames, with no directories and a limit of 192 files per disk (called volume ). PCOS requires significant part of the main memory. Operating system with BASIC interpreter takes 64 KB RAM, another 16 KB are reserved for screen output and user is left with only around 40 KB RAM on unexpanded machine. Version 2.0 supports dynamic memory allocation alleviating segmented memory limitations of

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