A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the user. The term “virus” is also commonly but erroneously used to refer to other types of malware, adware and spyware programs that do not have the reproductive ability. A true virus can only spread from one computer to another when its host (some form of executable code) is taken to the target computer, for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, or USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer.

Viruses are sometimes confused with computer worms and Trojan horses, which are technically different. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a program that appears harmless but has a hidden agenda. Worms and Trojans, like viruses, may cause harm to either a computer system’s hosted data, functional performance, or networking throughput, when they are executed. Some viruses and other malware have symptoms noticeable to the computer user, but most are surreptitious. This makes it hard for the average user to notice, find and disable and is why specialist anti-virus programs are now commonplace.

Most personal computers are now connected to the Internet and to local area networks, facilitating the spread of malicious code. Today’s viruses may also take advantage of network services such as the World Wide Web, e-mail, Instant Messaging and file sharing systems to spread, blurring the line between viruses and worms. Furthermore, some sources use an alternative terminology in which a virus is any form of self-replicating malware.

There are a few operating systems that dont get infected such as mac os, linux, and ubuntu. Viruses sometimes appear as .bat or .exe.

Abraham Lincoln and Martin Luther King Jr. were both against slavery. They both played a very big part in ending slavery. Though Abraham Lincoln has been one of the people identified as most responsible for the abolition of slavery, he maintained that the Constitution prohibited the federal government from abolishing slavery in states where it already existed. Initially, Lincoln expected to bring about the eventual extinction of slavery by stopping its further expansion into any U.S. territory, and by offering compensated emancipation (an offer accepted only by Washington, D.C). The Republican Party platform in 1860, was that slavery should not be allowed to expand into any more territories. Most Americans agreed that if all future states admitted to the Union were to be free states, that slavery would eventually become extinct.

In 1842, Lincoln had married into a prominent Kentucky family of slaveowners. (His brothers-in-law, Ben Hardin Helm would later serve as a Brig. General in the Confederacy, leading the 1st Kentucky Cavalry of the Orphan Brigade.) Lincoln returned to the political stage as a result of the 1854 Kansas-Nebraska Act and soon became a leading opponent of the Slave Power–that is the political power of the southern slave owners. The 1854 Kansas-Nebraska Act, written to form the territories of Kansas and Nebraska, included language, designed by Stephen A. Douglas,^[1] which allowed the settlers to decide whether they would or would not accept slavery in their region. Lincoln saw this as a repeal of the 1820 Missouri Compromise which had outlawed slavery above the 36-30′ parallel.

Lincoln’s critics, especially abolitionists and Radical Republicans, said he moved too slowly as President to end slavery. In his written response to Horace Greeley’s editorial (see below), having already discussed a draft of the Emancipation Proclamation with his cabinet, Lincoln wrote, “If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that…I have here stated my purpose according to my view of official duty; and I intend no modification of my oft-expressed personal wish that all men everywhere could be free.”

During the American Civil War, Lincoln used the war powers of the presidency to issue the Emancipation Proclamation, which declared “all persons held as slaves within any State or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free” but exempted border states and those areas of slave states already under Union control. As a practical matter, at first the Proclamation could only be enforced to free those slaves that had already escaped to the Union side. However, millions more were freed as more areas of the South came under Union control.

During the war, Lincoln was instrumental in the adoption of the Thirteenth Amendment to the United States Constitution, which outlawed slavery everywhere in the United States. This amendment was finally ratified in December 1865, after Lincoln’s assasination.

Martin Luther King Jr didn’t freed slavery he freed the law that black people and white people can be equal. Presdent Lincoin freed slavery.

Martin Luther King, Jr. (January 15, 1929 – April 4, 1968) was an African American clergyman, activist and prominent leader in the American civil rights movement. His main legacy was to secure progress on civil rights in the United States and he is frequently referenced as a human rights icon today.

A Baptist minister,^[1] King became a civil rights activist early in his career. He led the 1955 Montgomery Bus Boycott and helped found the Southern Christian Leadership Conference in 1957, serving as its first president.

King’s efforts led to the 1963 March on Washington, where King delivered his “I Have a Dream” speech. There, he raised public consciousness of the civil rights movement and established himself as one of the greatest orators in U.S. history.

In 1964, King became the youngest person to receive the Nobel Peace Prize for his work to end racial segregation and racial discrimination through civil disobedience and other non-violent means. By the time of his death in 1968, he had refocused his efforts on ending poverty and opposing the Vietnam War, both from a religious perspective.

King was assassinated on April 4, 1968, in Memphis, Tennessee. He was posthumously awarded the Presidential Medal of Freedom in 1977 and Congressional Gold Medal in 2004; Martin Luther King, Jr. Day was established as a U.S. national holiday in 1986.

Martin Luther King, Jr., was born on January 15, 1929, in Atlanta, Georgia. He was the son of the Reverend Martin Luther King, Sr. and Alberta Williams King.^[2] King’s father was born “Michael King”, and Martin Luther King, Jr., was originally named “Michael King, Jr.”, until the family traveled to Europe in 1934 and visited Germany. His father soon changed both of their names to Martin in honor of the German Protestant leader Martin Luther.^[3] He had an older sister, Willie Christine King, and a younger brother Alfred Daniel Williams King.^[4] King sang with his church choir at the 1939 Atlanta premiere of the movie Gone with the Wind.^[5]

Growing up in Atlanta, King attended Booker T. Washington High School. He skipped ninth and twelfth grade, and entered Morehouse College at age fifteen without formally graduating from high school.^[6] In 1948, he graduated from Morehouse with a Bachelor of Arts degree in sociology,^[7] and enrolled in Crozer Theological Seminary in Chester, Pennsylvania, from which he graduated with a Bachelor of Divinity degree in 1951.^[8] King then began doctoral studies in systematic theology at Boston University and received his Doctor of Philosophy on June 5, 1955. A 1980s inquiry concluded portions of his dissertation had been plagiarized and he had acted improperly but that his dissertation still “makes an intelligent contribution to scholarship”.^[9][10]

King married Coretta Scott, on June 18, 1953, on the lawn of her parents’ house in her hometown of Heiberger, Alabama.^[11] King and Scott had four children; Yolanda King, Martin Luther King III, Dexter Scott King, and Bernice King.^[12] King became pastor of the Dexter Avenue Baptist Church in Montgomery, Alabama when he was twenty-five years old in 1954.^[13]

Abraham Lincoln (February 12, 1809 – April 15, 1865) was the sixteenth President of the United States. He successfully led the country through its greatest internal crisis, the American Civil War, preserving the Union and ending slavery. Assassinated as the war was drawing to a close, Lincoln had been the first Republican elected to the Presidency. Before his presidency, he was a lawyer, an Illinois state legislator, a member of the United States House of Representatives, and twice an unsuccessful candidate for election to the Senate.

As an outspoken opponent of the expansion of slavery in the United States,^[1][2] Lincoln won the Republican Party nomination in 1860 and was elected president later that year. His tenure in office was occupied primarily with the defeat of the secessionist Confederate States of America in the American Civil War. He introduced measures that resulted in the abolition of slavery, issuing his Emancipation Proclamation in 1863 and promoting the passage of the Thirteenth Amendment to the Constitution, which passed Congress before Lincoln’s death and was ratified by the states later in 1865.

Lincoln closely supervised the victorious war effort, especially the selection of top generals, including Ulysses S. Grant. Historians have concluded that he handled the factions of the Republican Party well, bringing leaders of each faction into his cabinet and forcing them to cooperate. Lincoln successfully defused the Trent Affair, a war scare with the Britain in 1861. Under his leadership, the Union took control of the border slave states at the start of the war. Additionally, he managed his own reelection in the 1864 presidential election.

Opponents of the war (also known as “Copperheads“) criticized Lincoln for refusing to compromise on the slavery issue. Conversely, the Radical Republicans, an abolitionist faction of the Republican Party, criticized him for moving too slowly in abolishing slavery. Even with these road blocks, Lincoln successfully rallied public opinion through his rhetoric and speeches; his Gettysburg Address is but one example of this. At the close of the war, Lincoln held a moderate view of Reconstruction, seeking to speedily reunite the nation through a policy of generous reconciliation. His assassination in 1865 was the first presidential assassination in U.S. history and as a result Lincoln is seen as a martyr for the ideal of national unity and human rights.^{[citation needed]} Lincoln has been consistently ranked by scholars as one of the greatest U.S. Presidents.

Barack Hussein Obama II (pronounced /bəˈrɑːk hʊˈseɪn oʊˈbɑːmə/; born August 4, 1961) is the forty-fourth and current President of the United States of America. He is the first African American to hold the office. Obama was the junior United States Senator from Illinois from January 3, 2005, until his resignation on November 16, 2008, following his election to the presidency. He was sworn in as President on January 20, 2009, in an inaugural ceremony at the U.S. Capitol.

Obama is a graduate of Columbia University and Harvard Law School, where he was the first African-American president of the Harvard Law Review. He worked as a community organizer, and practiced as a civil rights attorney in Chicago before serving three terms in the Illinois Senate from 1997 to 2004. He also taught Constitutional Law at the University of Chicago Law School from 1992 to 2004. Following an unsuccessful bid for a seat in the U.S. House of Representatives in 2000, Obama was elected to the Senate in November 2004. Obama delivered the keynote address at the Democratic National Convention in July 2004.

As a member of the Democratic minority in the 109th Congress, Obama helped create legislation to control conventional weapons and to promote greater public accountability in the use of federal funds. He also made official trips to Eastern Europe, the Middle East, and Africa. During the 110th Congress, he helped create legislation regarding lobbying and electoral fraud, climate change, nuclear terrorism, and care for U.S. military personnel returning from combat assignments in Iraq and Afghanistan.

Barack Obama was born at the Kapi’olani Medical Center for Women & Children in Honolulu, Hawaii,^[3][4] to Ann Dunham, a white American from Wichita, Kansas^[5] of English and Irish descent.^[6][7] Obama’s father was Barack Obama, Sr., a Luo from Nyang’oma Kogelo, Nyanza Province, Kenya. His parents met in 1960 while attending the University of Hawaii at Mānoa, where his father was a foreign student.^[8][9] The couple married on February 2, 1961;^[10] they separated when Obama was two years old and divorced in 1964.^[9] Obama’s father returned to Kenya and saw his son only once more before dying in an automobile accident in 1982.^[11]

After her divorce, Dunham married Indonesian student Lolo Soetoro, who was attending college in Hawaii. When Soeharto, a military leader in Soetoro’s home country, came to power in 1967, all students studying abroad were recalled and the family moved to Indonesia.^[12] There Obama attended local schools in Jakarta, such as Besuki Public School and St. Francis of Assisi School, until he was ten years old.

He then returned to Honolulu to live with his maternal grandparents, Madelyn and Stanley Armour Dunham, while attending Punahou School from the fifth grade in 1971 until his graduation from high school in 1979.^[13] Obama’s mother returned to Hawaii in 1972 for five years, and then in 1977 went back to Indonesia, where she worked as an anthropological field worker. She stayed there most of the rest of her life, returning to Hawaii in 1994. She died of ovarian cancer in 1995.^[14]

Right-to-left: Barack Obama and half-sister Maya Soetoro-Ng, with their mother Ann Dunham and grandfather Stanley Dunham, in Hawaii (early 1970s)

Of his early childhood, Obama has recalled, “That my father looked nothing like the people around me — that he was black as pitch, my mother white as milk — barely registered in my mind.”^[15] In his 1995 memoir, he described his struggles as a young adult to reconcile social perceptions of his multiracial heritage.^[16] He wrote that he used alcohol, marijuana, and cocaine during his teenage years to “push questions of who I was out of my mind”.^[17] At the 2008 Civil Forum on the Presidency, Obama identified his high-school drug use as his “greatest moral failure.”^[18]

Some of his fellow students at Punahou School later told the Honolulu Star-Bulletin that Obama was mature for his age, and that he sometimes attended college parties and other events in order to associate with African American students and military service people. Reflecting later on his formative years in Honolulu, Obama wrote: “The opportunity that Hawaii offered — to experience a variety of cultures in a climate of mutual respect — became an integral part of my world view, and a basis for the values that I hold most dear.”^[19]

Following high school, Obama moved to Los Angeles, where he studied at Occidental College for two years.^[20] He then transferred to Columbia University in New York City, where he majored in political science with a specialization in international relations.^[21] Obama graduated with a B.A. from Columbia in 1983. He worked for a year at the Business International Corporation^[22][23] and then at the New York Public Interest Research Group.^[24][25]

After four years in New York City, Obama moved to Chicago, where he was hired as director of the Developing Communities Project (DCP), a church-based community organization originally comprising eight Catholic parishes in Greater Roseland (Roseland, West Pullman, and Riverdale) on Chicago’s far South Side. He worked there for three years from June 1985 to May 1988.^[24][26] During his three years as the DCP’s director, its staff grew from one to thirteen and its annual budget grew from $70,000 to $400,000. His achievements included helping set up a job training program, a college preparatory tutoring program, and a tenants’ rights organization in Altgeld Gardens.^[27] Obama also worked as a consultant and instructor for the Gamaliel Foundation, a community organizing institute.^[28] In mid-1988, he traveled for the first time to Europe for three weeks and then for five weeks in Kenya, where he met many of his paternal relatives for the first time.^[29]

Obama entered Harvard Law School in late 1988. He was selected as an editor of the Harvard Law Review at the end of his first year,^[30] and president of the journal in his second year.^[31] During his summers, he returned to Chicago where he worked as a summer associate at the law firms of Sidley & Austin in 1989 and Hopkins & Sutter in 1990.^[32] After graduating with a Juris Doctor (J.D.) magna cum laude^[33][34] from Harvard in 1991, he returned to Chicago.^[30]

Obama’s election as the first black president of the Harvard Law Review gained national media attention^[31] and led to a publishing contract and advance for a book about race relations.^[35] In an effort to recruit him to their faculty, the University of Chicago Law School provided Obama with a fellowship and an office to work on his book.^[35] He originally planned to finish the book in one year, but it took much longer as the book evolved into a personal memoir. In order to work without interruptions, Obama and his wife, Michelle, traveled to Bali where he wrote for several months. The manuscript was finally published in mid-1995 as Dreams from My Father.^[35]

Obama directed Illinois’s Project Vote from April to October 1992, a voter registration drive with a staff of ten and seven hundred volunteers; it achieved its goal of registering 150,000 of 400,000 unregistered African Americans in the state, and led to Crain’s Chicago Business naming Obama to its 1993 list of “40 under Forty” powers to be.^[36][37]

Obama served for twelve years as a professor at the University of Chicago Law School, teaching Constitutional Law. He was first classified as a Lecturer from 1992 to 1996, and then as a Senior Lecturer from 1996 to 2004.^[38] He also joined Davis, Miner, Barnhill & Galland, a twelve-attorney law firm specializing in civil rights litigation and neighborhood economic development, where he was an associate for three years from 1993 to 1996, then of counsel from 1996 to 2004, with his law license becoming inactive in 2002.^[24][39][40]

Obama was a founding member of the board of directors of Public Allies in 1992, resigning before his wife, Michelle, became the founding executive director of Public Allies Chicago in early 1993.^[24][41] He served from 1994 to 2002 on the board of directors of the Woods Fund of Chicago, which in 1985 had been the first foundation to fund the Developing Communities Project, and also from 1994 to 2002 on the board of directors of the Joyce Foundation.^[24] Obama served on the board of directors of the Chicago Annenberg Challenge from 1995 to 2002, as founding president and chairman of the board of directors from 1995 to 1999.^[24] He also served on the board of directors of the Chicago Lawyers’ Committee for Civil Rights Under Law, the Center for Neighborhood Technology, and the Lugenia Burns Hope Center.^[24]

Macintosh, commonly shortened to Mac, is a brand name which covers several lines of personal computers designed, developed, and marketed by Apple Inc. The Macintosh was introduced on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a graphical user interface rather than a command line interface.

Through the second half of the 1980s, the company built market share only to see it dissipate in the 1990s as the personal computer market shifted towards IBM PC compatible machines running MS-DOS and Microsoft Windows. Apple consolidated multiple consumer-level desktop models into the 1998 iMac all-in-one, which was a sales success and saw the Macintosh brand revitalized. Current Mac systems are mainly targeted at the home, education, and creative professional markets. They are: the aforementioned (though upgraded) iMac and the entry-level Mac Mini desktop models, the workstation-level Mac Pro tower, the MacBook, MacBook Air and MacBook Pro laptops, and the Xserve server.

Production of the Mac is based on a vertical integration model in that Apple facilitates all aspects of its hardware and creates its own operating system that is pre-installed on all Macs. This is in contrast to most IBM PC compatibles, where multiple vendors create hardware intended to run another company’s software. Apple exclusively produces Mac hardware, choosing internal systems, designs, and prices. Apple does use third party components, however; current Macintosh CPUs use Intel’s x86 architecture. Previous models used the AIM alliance’s PowerPC and early models used Motorola’s 68k. Apple also develops the operating system for Macs, currently Mac OS X 10.5 “Leopard”. The modern Mac, like other personal computers, is capable of running alternative operating systems such as Linux, FreeBSD, and Microsoft Windows, the latter of which is considered to be the Mac’s biggest competitor.

1979 to 1984: Development

Part of the original Macintosh design team, as seen on the cover of Revolution in the Valley.
Left to right: George Crow, Joanna Hoffman, Burrell Smith, Andy Hertzfeld, a Macintosh, Bill Atkinson, Jerry Manock.

The Macintosh project started in the late 1970s with Jef Raskin, an Apple employee, who envisioned an easy-to-use, low-cost computer for the average consumer. He wanted to name the computer after his favorite type of apple, the McIntosh, but the name had to be changed for legal reasons.^[1] In September 1979, Raskin was authorized to start hiring for the project, and he began to look for an engineer who could put together a prototype. Bill Atkinson, a member of Apple’s Lisa team (which was developing a similar but higher-end computer), introduced him to Burrell Smith, a service technician who had been hired earlier that year. Over the years, Raskin assembled a large development team that designed and built the original Macintosh hardware and software; besides Raskin, Atkinson and Smith, the team included Chris Espinosa, Joanna Hoffman, George Crow, Jerry Manock, Susan Kare, Andy Hertzfeld, and Daniel Kottke.

Smith’s first Macintosh board was built to Raskin’s design specifications: it had 64 kilobytes (KB) of RAM, used the Motorola 6809E microprocessor, and was capable of supporting a 256×256 pixel black-and-white bitmap display. Bud Tribble, a Macintosh programmer, was interested in running the Lisa’s graphical programs on the Macintosh, and asked Smith whether he could incorporate the Lisa’s Motorola 68000 microprocessor into the Mac while still keeping the production cost down. By December 1980, Smith had succeeded in designing a board that not only used the 68000, but bumped its speed from 5 to 8 megahertz (MHz); this board also had the capacity to support a 384×256 pixel display. Smith’s design used fewer RAM chips than the Lisa, which made production of the board significantly more cost-efficient. The final Mac design was self-contained and had the complete QuickDraw picture language and interpreter in 64 Kb of ROM – far more than most other computers; it had 128 KB of RAM, in the form of sixteen 64 kilobit (Kb) RAM chips soldered to the logicboard. Though there were no memory slots, its RAM was expandable to 512 KB by means of soldering sixteen chip sockets to accept 256 Kb RAM chips in place of the factory-installed chips. The final product’s screen was a 9-inch, 512×342 pixel monochrome display, exceeding the prototypes.^[2]

The original 1984 Mac OS desktop featured a radically new graphical user interface. Users communicated with the computer not through abstract lines of code but rather using a metaphorical desktop that included items that the user was already familiar with.

The design caught the attention of Steve Jobs, co-founder of Apple. Realizing that the Macintosh was more marketable than the Lisa, he began to focus his attention on the project. Raskin finally left the Macintosh project in 1981 over a personality conflict with Jobs, and the final Macintosh design is said to be closer to Jobs’ ideas than Raskin’s.^[3] After hearing of the pioneering GUI technology being developed at Xerox PARC, Jobs had negotiated a visit to see the Xerox Alto computer and Smalltalk development tools in exchange for Apple stock options. The Lisa and Macintosh user interfaces were partially influenced by technology seen at Xerox PARC and were combined with the Macintosh group’s own ideas.^[4] Jobs also commissioned industrial designer Hartmut Esslinger to work on the Macintosh line, resulting in the “Snow White” design language; although it came too late for the earliest Macs, it was implemented in most other mid- to late-1980s Apple computers.^[5] However, Jobs’ leadership at the Macintosh project was short-lived; after an internal power struggle with new CEO John Sculley, Jobs angrily resigned from Apple in 1985, went on to found NeXT, another computer company, and did not return until 1997.

[edit] 1984: Introduction

This television commercial, which notably aired during the Super Bowl, launched the original Macintosh.

The Macintosh 128k was announced to the press in October 1983, followed by an 18-page brochure included with various magazines in December.^[6] The Macintosh was introduced by the now famous US$1.5 million Ridley Scott television commercial, “1984“. ^[7] The commercial most notably aired during the third quarter of Super Bowl XVIII on 22 January 1984 and is now considered a “watershed event”^[8] and a “masterpiece.”^[9] 1984 used an unnamed heroine to represent the coming of the Macintosh (indicated by her white tank top with a Picasso-style picture of Apple’s Macintosh computer on it) as a means of saving humanity from “conformity” (Big Brother).^[10] These images were an allusion to George Orwell’s noted novel, Nineteen Eighty-Four, which described a dystopian future ruled by a televised “Big Brother.”

Two days after the 1984 ad aired, the Macintosh went on sale. It came bundled with two applications designed to show off its interface: MacWrite and MacPaint. Although the Mac garnered an immediate, enthusiastic following, it was too radical for some, who labeled it a mere “toy.” Because the machine was entirely designed around the GUI, existing text-mode and command-driven applications had to be redesigned and the programming code rewritten; this was a challenging undertaking that many software developers shied away from, and resulted in an initial lack of software for the new system. In April 1984 Microsoft’s MultiPlan migrated over from MS-DOS, followed by Microsoft Word in January 1985.^[11] In 1985, Lotus Software introduced Lotus Jazz after the success of Lotus 1-2-3 for the IBM PC, although it was largely a flop.^[12] Apple introduced Macintosh Office the same year with the lemmings ad. Infamous for insulting its own potential customers, it was not successful.^[13]

For a special post-election edition of Newsweek in November 1984, Apple spent more than US$2.5 million to buy all 39 of the advertising pages in the issue.^[14] Apple also ran a “Test Drive a Macintosh” promotion, in which potential buyers with a credit card could take home a Macintosh for 24 hours and return it to a dealer afterwards. While 200,000 people participated, dealers disliked the promotion, the supply of computers was insufficient for demand, and many were returned in such a bad shape that they could no longer be sold. This marketing campaign caused CEO John Sculley to raise the price from US$1,995 to US$2,495 (adjusting for inflation, about $5,000 in 2007).^[13][15]

[edit] 1985 to 1989: Desktop publishing era

In 1985, the combination of the Mac, Apple’s LaserWriter printer, and Mac-specific software like Boston Software’s MacPublisher and Aldus PageMaker enabled users to design, preview, and print page layouts complete with text and graphics—an activity to become known as desktop publishing. Initially, desktop publishing was unique to the Macintosh, but eventually became available for IBM PC users as well. Later, applications such as Macromedia FreeHand, QuarkXPress, Adobe Photoshop, and Adobe Illustrator strengthened the Mac’s position as a graphics computer and helped to expand the emerging desktop publishing market.

The limitations of the first Mac soon became clear: it had very little memory, even compared with other personal computers in 1984, and could not be expanded easily; and it lacked a hard disk drive or the means to attach one easily. In October 1985, Apple increased the Mac’s memory to 512 KB, but it was inconvenient and difficult to expand the memory of a 128 KB Mac. In an attempt to improve connectivity, Apple released the Macintosh Plus on January 10, 1986 for US$2,600. It offered one megabyte of RAM, expandable to four, and a then-revolutionary SCSI parallel interface, allowing up to seven peripherals—such as hard drives and scanners—to be attached to the machine. Its floppy drive was increased to an 800 KB capacity. The Mac Plus was an immediate success and remained in production until October 15, 1990; on sale for just over four years and ten months, it was the longest-lived Macintosh in Apple’s history.^[16]

The Macintosh II, one of the first expandable Macintosh models.

Other issues remained, particularly the low processor speed and limited graphics ability, which had hobbled the Mac’s ability to make inroads into the business computing market. Updated Motorola CPUs made a faster machine possible, and in 1987 Apple took advantage of the new Motorola technology and introduced the Macintosh II, which used a 16 MHz Motorola 68020 processor. The primary improvement in the Macintosh II was Color QuickDraw in ROM, a color version of the graphics language which was the heart of the machine. Among the many innovations in Color QuickDraw were an ability to handle any display size, any color depth, and multiple monitors.

The Macintosh II marked the start of a new direction for the Macintosh, as now, for the first time, it had an open architecture, with several expansion slots, support for color graphics, and a modular break-out design similar to that of the IBM PC and inspired by Apple’s other line, the expandable Apple II series. It had an internal hard drive and a power supply with a fan, which was initially fairly loud.^[17] One third-party developer sold a device to regulate fan speed based on a heat sensor, but it voided the warranty.^[18] Later Macintosh computers had quieter power supplies and hard drives.

In September 1986 Apple introduced the Macintosh Programmer’s Workshop, or MPW that allowed software developers to create software for Macintosh on Macintosh, rather than cross-developing from a Lisa. In August 1987 Apple unveiled HyperCard, and introduced MultiFinder, which added cooperative multitasking to the Macintosh. In the Fall Apple bundled both with every Macintosh.

Alongside the Macintosh II, the Macintosh SE was released, the first compact Mac with a 20 MB internal hard drive^[19][20] and one expansion slot. The SE also updated Jerry Manock and Terry Oyama’s original design and shared the Macintosh II’s Snow White design language, as well as the new Apple Desktop Bus (ADB) mouse and keyboard that had first appeared on the Apple IIGS some months earlier.

In 1987, Apple spun off its software business as Claris. It was given the code and rights to several applications that had been written within Apple, notably MacWrite, MacPaint, and MacProject. In the late 1980s, Claris released a number of revamped software titles; the result was the “Pro” series, including MacPaint Pro, MacDraw Pro, MacWrite Pro, and FileMaker Pro. To provide a complete office suite, Claris purchased the rights to the Informix Wingz spreadsheet on the Mac, renaming it Claris Resolve, and added the new presentation software Claris Impact. By the early 1990s, Claris applications were shipping with the majority of consumer-level Macintoshes and were extremely popular. In 1991, Claris released ClarisWorks, which soon became their second best-selling application. When Claris was reincorporated back into Apple in 1998, ClarisWorks was renamed AppleWorks beginning with version 5.0.^[21]

The Macintosh Portable was Apple’s first portable Macintosh. It was available from 1989 to 1991 and could run System 6 and System 7.

In 1988, Apple sued Microsoft and Hewlett-Packard on the grounds that they infringed Apple’s copyrighted GUI, citing (among other things) the use of rectangular, overlapping, and resizable windows. After four years, the case was decided against Apple, as were later appeals. Apple’s actions were criticized by some in the software community, including the Free Software Foundation (FSF), who felt Apple was trying to monopolize on GUIs in general, and boycotted GNU software for the Macintosh platform for seven years.^[22][23]

With the new Motorola 68030 processor came the Macintosh IIx in 1988, which had benefited from internal improvements, including an on-board MMU. It was followed in 1989 by a more compact version with fewer slots (the Macintosh IIcx) and a version of the Mac SE powered by the 16 MHz 68030 (the Macintosh SE/30, breaking the existing naming convention to avoid the name “SEx”). Later that year, the Macintosh IIci, running at 25 MHz, was the first Mac to be “32-bit clean,” allowing it to natively support more than 8 MB of RAM, unlike its predecessors, which had “32-bit dirty” ROMs (8 of the 32 bits available for addressing were used for OS-level flags). System 7 was the first Macintosh operating system to support 32-bit addressing.^[24] Apple also introduced the Macintosh Portable, a 16 MHz 68000 machine with an active matrix flat panel display that was backlit on some models.^[25] The following year the Macintosh IIfx, starting at US$9,900, was unveiled. Apart from its fast 40 MHz 68030 processor, it had significant internal architectural improvements, including faster memory and two Apple II-era CPUs dedicated to I/O processing.^[26]

[edit] 1990 to 1998: Growth and decline

The Macintosh Classic, Apple’s early 1990s budget model.

Microsoft Windows 3.0, which began to approach the Macintosh operating system in both performance and feature set, was released in May 1990 and was a usable, less expensive alternative to the Macintosh platform. Apple’s response was to introduce a range of relatively inexpensive Macs in October 1990. The Macintosh Classic, essentially a less expensive version of the Macintosh Plus, sold for US$999,^[27] making it the least expensive Mac until early 2001. The 68020-powered Macintosh LC, in its distinctive “pizza box” case, was available for US$1800; it offered color graphics and was accompanied by a new, low-cost 512 × 384 pixel monitor.^[28] The Macintosh IIsi, essentially a 20 MHz IIci with only one expansion slot, cost US$2500.^[29] All three machines sold well,^[30] although Apple’s profit margin was considerably lower than on earlier machines.^[27]

System 7 was the first major upgrade of the Macintosh operating system.

The year 1991 saw the much-anticipated release of System 7, a 32-bit rewrite of the Macintosh operating system that improved its handling of color graphics, memory addressing, networking, and co-operative multitasking, and introduced virtual memory. Later that year, Apple introduced the Macintosh Quadra 700 and 900, the first Macs to employ the faster Motorola 68040 processor. They were joined by improved versions of the previous year’s top sellers, the Macintosh Classic II and Macintosh LC II, which used a 16 MHz 68030 CPU. Also during this time, the Macintosh began to shed the “Snow White” design language, along with the expensive consulting fees they were paying to Frogdesign, in favor of bringing the work in-house by establishing the Apple Industrial Design Group to establish a new fresh look to go with the new operating system.

The PowerBook 100 (shown here), 140 and 170 introduced a line of professional laptop Macs. They pioneered notebook ergonomics by placing the keyboard behind a palm rest.

In October 1991, the Macintosh Portable was replaced by the first three models in Apple’s enduring PowerBook range—the PowerBook 100, a miniaturized Portable; the 16 MHz 68030 PowerBook 140; and the 25 MHz 68030 PowerBook 170. They were the first portable computers with the keyboard behind a palm rest, and with a built-in pointing device (a trackball) in front of the keyboard.

In 1992, Apple started to sell a low-end Mac, the Performa, through nontraditional dealers. At Apple dealers, a mid-range version of the Quadra series called the Macintosh Centris was offered, only to be quickly renamed Quadra when buyers became confused by the range of Classics, LCs, IIs, Quadras, Performas, and Centrises. Apple also unveiled the miniaturized PowerBook Duo range. It was intended to be docked to a base station for desktop-like functionality in the workplace, and was sold until early 1997. In May 1994, Apple released the second-generation PowerBook models, the PowerBook 500 series, which introduced the novel trackpad.

Also in 1994, Apple abandoned Motorola CPUs for the RISC PowerPC architecture developed by the AIM alliance of Apple Computer, IBM, and Motorola. The Power Macintosh line, the first to use the new chips, proved to be highly successful, with over a million PowerPC units sold in nine months.

Despite these technical and commercial successes, Microsoft and Intel began to rapidly lower Apple’s market share with the Windows 95 operating system and Pentium processors respectively. These significantly enhanced the multimedia capability and performance of IBM PC compatible computers, and brought Windows still closer to the Mac GUI. In response, Apple started the Macintosh clone program, by which third-parties manufactured hardware to run Apple’s System 7. This succeeded in increasing the Macintosh’s market share somewhat and provided cheaper hardware for consumers, but hurt Apple financially. As a result, when Steve Jobs returned to Apple in 1997, he ordered that the OS that had been previewed as version 7.7 be branded Mac OS 8. Since Apple had licensed only System 7 to third-parties, this move effectively ended the clone line. The decision caused significant financial losses for companies like Motorola and Power Computing Corporation, which had invested substantial resources in creating their own Mac-compatible hardware.

1998 to 2005: New beginnings

The original “Bondi Blue” iMac G3, introduced in 1998. One of the first products produced under CEO Steve Jobs since he left the company in the mid eighties, it brought Apple back into profitability.

In 1998, a year after Steve Jobs had returned to the company, Apple introduced an all-in-one Macintosh called the iMac. Its translucent plastic case, originally Bondi blue and later many other colors, is considered an industrial design hallmark of the late 1990s. The iMac did away with most of Apple’s standard (and usually proprietary) connections, such as SCSI and ADB, in favor of two USB ports. It also had no internal floppy disk drive and instead used compact disks for removable storage. It proved to be phenomenally successful, with 800,000 units sold in 139 days, making the company an annual profit of US$309 million—Apple’s first profitable year since Michael Spindler took over as CEO in 1995. The “blue and white” aesthetic was applied to the Power Macintosh, and then to a new product: the iBook. Introduced in July 1999, the iBook was Apple’s first consumer-level laptop computer. More than 140,000 pre-orders were placed before it started shipping in September, and by October it was as much a sales hit as the iMac. Apple continued to add new products to their lineup, such as the Cube, the eMac for the education market and PowerBook G4 laptop for professionals. The original iMac used a G3 processor, but the upgrades to G4 and then to G5 chips were accompanied by a new design, dropping the array of colors in favor of white plastic. Current iMacs use aluminum enclosures. On January 11, 2005, Apple announced the release of the Mac Mini priced at US$499,^[48] the least expensive Mac to date.

Screenshot of Mac OS X v10.5 “Leopard”, the operating system included on all new Macs.

Mac OS continued to evolve up to version 9.2.2, but its dated architecture—though retrofitted a few times (for example, as part of the PowerPC port, a nanokernel was added and Mac OS 8.6 was modified to support Multiprocessing Services 2.0 in Mac OS 8.6)^[49]—made a replacement necessary. As such, Apple introduced Mac OS X, a fully overhauled Unix-based successor to Mac OS 9, using Darwin, XNU, and Mach as foundations, and based on NEXTSTEP. Mac OS X was not released to the public until September 2000, as the Mac OS X Public Beta, with an Aqua interface. At US$29.99, it allowed adventurous Mac users to sample Apple’s new operating system and provide feedback for the actual release.^[50] The initial release of Mac OS X, 10.0 (nicknamed Cheetah), was released on March 24, 2001. Older Mac OS applications could still run under early Mac OS X versions, using an environment called Classic (though Apple has since removed Classic from Mac OS X in version 10.5, “Leopard”). Subsequent releases of Mac OS X were 10.1 “Puma”, (September 25, 2001), 10.2 “Jaguar”, (August 24, 2002), 10.3 “Panther”, (October 24, 2003), 10.4 “Tiger”, (April 29, 2005) and 10.5 “Leopard” (October 26, 2007). The Intel version of Leopard received certification as a Unix implementation by The Open Group.

2006 onward: Intel era

The MacBook Pro is the first Mac notebook to use an Intel processor. It was released at Macworld 2006.

Partially because of a failure to produce laptop-ready G5 chips, Apple discontinued the use of PowerPC microprocessors in 2006. At WWDC 2005, Steve Jobs revealed this transition and also noted that Mac OS X was in development to run both on Intel and PowerPC architecture from the very beginning. All new Macs now use x86 processors made by Intel, and some Macs were given new names to signify the switch. Intel-based Macs can run pre-existing PowerPC-based software using an emulator called Rosetta, although at noticeably slower speeds than native programs, but the Classic environment is unavailable. With the release of Intel-based Mac computers, the potential to natively run Windows-based operating systems on Apple hardware without the need for emulation software such as Virtual PC was introduced. In March 2006, a group of hackers announced that they were able to run Windows XP on an Intel-based Mac. The group has released their software as open source and has posted it for download on their website^.  On April 5, 2006 Apple announced the public beta availability of their own Boot Camp software which will allow owners of Intel-based Macs to install Windows XP on their machines; later versions added support for Windows Vista. Starting with Mac OS X 10.5, Boot Camp is now a standard feature.

In recent years, Apple has seen a significant boost in sales of Macs. Many claim that this is due, in part, to the success of the iPod, a halo effect whereby satisfied iPod owners purchase more Apple equipment. The inclusion of the Intel chips is also a factor. The iPod digital audio players have recaptured a brand awareness of the Mac line that had not been seen since its original release in 1984. From 2001 to 2007, Mac sales increased continuously on an annual basis. On October 22, 2007, Apple released its fourth quarter results, reporting shipment of 2,164,000 Macs—exceeding the previous company record for quarterly Macintosh shipments by over 400,000.

A homebuilt computer is a computer assembled from available components, rather than purchased as a complete system from a computer system supplier.

History

Computers have been built at home for a long time, starting with the Victorian era pioneer Charles Babbage in the 1820s. A century later, Konrad Zuse built his own machine when electromechanical relay technology was widely available. The hobby really took off with the early development of microprocessors, and since then many enthusiasts have constructed their own computers.

Early examples from the United Kingdom include the Newbear 77-68 and Nascom designs from the late 70’s and early 80’s. Some were made from kits of components, or simply distributed as board designs. The development of standardized S-100 bus components made the process easier, but the development of home computers, the IBM PC (and its derivatives and clones), and the industry of specialized component suppliers that grew up around this market in the mid 80’s have made building computers much easier. Computer building is no longer limited to specialists.

Development as a hobby

Assembling custom PCs from components is now a well established adjunct to PC gaming, and has evolved into a minor art form with case modifications such as illuminated case fans, cold cathode lamps, windowed and transparent cases, customized cabling, and stylized paint jobs. Overclocking enthusiasts take efficiency further, building systems that seek a higher performance than the CPU manufacturers’ rating by modifying core CPU voltages and clock settings, and using high-efficiency cooling strategies ranging from oversized heat sinks to advanced water cooling or refrigeration systems.

Standardization

The same availability of standardised PC components that makes computer building so easy and widespread has led to the development of small scale custom PC assembly; with so called “white box” PCs and commercial “build to order” services ranging in size from small local supply operations to large International operations.

Practically all PCs except laptops are largely built from interchangeable standard parts because PC manufacturers enjoy an advantage of scale, and the system assemblers derive a commercial advantage from multiple sources of interchangeable parts. Even in the more specialised laptop market, a considerable degree of standardization exists “under the covers”. Unfortunately many “big name” systems and especially laptops also contain components that vary widely from the “de facto” standards that generic PC systems follow, which are only obtainable from the system assemblers concerned.

Types

Since it is possible to adapt, expand, update, or otherwise customise any PC within the limits of the PCs conformance to standard component interfaces, homebuilt PC systems form a continuum from standard system suppliers offerings adapted with an alternative video card or uprated hard disk, up to systems built from scratch from components, owing nothing to any specific system assembler.

Kits and barebones systems

Computer kits include all of the hardware (and sometimes the operating system software, as well) needed to build a complete computer. Because the components are pre-selected by the vendor, the planning and design stages of the computer-building project are eliminated, and the builder’s experience will consist solely of assembling the computer and installing the operating system. In theory, the kit supplier will have tested the components to assure that they are compatible and free of conflicts.

A “barebones computer” is a variation on the kit concept. A barebones system typically consists of a computer case with a power supply, motherboard, processor, and processor cooler. A wide variety of other combinations are also possible: some barebones systems come with just the case and the motherboard, while other systems are virtually complete. In either case, the purchaser will need to obtain and install whatever parts are not included in the barebones kit (typically the hard drive, Random Access Memory, peripheral devices, and operating system).

Like mass-produced computers, barebones systems and computer kits are often targeted to particular types of users, and even different age groups. Because many home computer builders are gamers, for example, and because gamers are often young people, barebones computers marketed as “gaming systems” often include features such as neon lights and brightly-colored cases, as well as features more directly related to performance such as a fast processor, a generous amount of Random Access Memory, and a powerful video card. Other kits and barebones systems may be specifically marketed to users of an “alternative” operating system like Linux, with components selected on the basis of their compatibility and performance with that operating system.

Scavenged and “cannibalized” systems

Many amateur-built computers are built primarily from used or “spare” parts. There are variety of possible reasons why a person would choose to build a “new” computer from old parts. For example, it’s sometimes necessary to build a computer that will run an obsolete operating system or proprietary software for which updates are no longer available, and which will not run properly on a current platform. Economic reasons may also require an individual to build a new computer from used parts, especially among youth or in developing countries where the cost of new equipment places it out of reach of average people.

Advantages and disadvantages

Building one’s own computer arguably affords tangible benefits compared to purchasing a mass-produced model, such as:

• Being able to choose exactly which components are to be used.
• Customizing the machine to the user’s exact needs and preferences.
• Avoiding the advertising links, trial software, and other commission-driven additions and modifications that increasingly are made to mass-market computers prior to their being shipped.
• Ensure that one has all the individual driver and OS discs – many manufactured computers only come with one or two discs. one of which is the OS, and another is a “restore to factory condition” disc, which included all the “Bloatware” mentioned above. This in inhibits latter modifiability (mentioned below).
• Being able to make modifications to the original build at a later date with little hassle.
• May be less expensive than a mass-manufactured PC, especially if extensively customization is desired.
• Enjoyment, personal satisfaction, and educational experience.

For the general public, however, the lack of technical support and warranty protection (other than what may or may not be provided by the individual component and software manufacturers) may be a significant disadvantage. However, one must remember that a person who is capable of designing and building a PC will most likely have sufficient knowledge and technical know-how to maintain his or her system, and will require little “technical support” from manufacturers.

Homebuilt computers and alternative operating systems

Side view of a typical homebuilt PC. The motherboard and internal components are on display.

Because almost all mass-manufactured PCs ship with some version of Microsoft Windows pre-installed, individuals who wish to use operating systems other than Windows (for example, Linux or BSD) often choose to build their own computers. Their reason for doing so is not always related to saving money on an operating system.

Because Microsoft Windows is the de facto standard for PCs, hardware device drivers can readily be found that will enable virtually any component designed for the PC architecture to function on a Windows platform. However, the same isn’t true for alternative operating systems like Linux and BSD, so these system users have to be careful to avoid hardware that is incompatible with their choice of operating system. Even among hardware devices that technically will “work” with these alternative operating systems, some will work better than others. Therefore, many users of non-Microsoft operating systems choose to build their own computers from components known to work particularly well with their preferred platforms.

Back to the Future: The Ride is a simulator ride based on the Back to the Future trilogy of films and is a mini-sequel to 1990’s Back to the Future Part III. It is located at Universal Studios Japan, previously at Universal Studios Florida and Universal Studios Hollywood and also Universal Studios Singapore in the future. The ride story centers on a first-person adventure through time, in pursuit of the trilogy’s villain, Biff Tannen.

The original attraction opened on May 2, 1991, at Universal Studios Florida. Back To The Future The Ride also opened on June 2, 1993 at Universal Studios Hollywood and on March 31, 2001 at Universal Studios Japan. The ride was actually planned to open in Orlando and Hollywood at the same time but due to foundation problems, the Hollywood version opened 2 years later.^[1] The original ride in Orlando enjoyed almost sixteen years of constant operation before its final closure, to little fanfare, on March 30, 2007, after operating at half capacity for over three months. The Hollywood ride publicly closed on Labor Day, September 3, 2007. In commemoration of its final month of operation, a special event was held with Christopher Lloyd and Bob Gale beginning the countdown to the ride’s closure in early August 2007.^[2] Additionally, a contest was announced with the grand prize winner receiving a classic 1981 De Lorean DMC-12 vehicle. The ride at Universal Studios Japan is still open, with no plans for closure at this time.

A new attraction based on the animated sitcom The Simpsons, known officially as The Simpsons Ride, replaced the Back to the Future: The Ride at Universal Studios Hollywood on May 19, 2008 and Universal Studios Florida on May 15, 2008.

About two years after the ride opened, one of the ride employees recorded the entire ride projector footage, in-car footage, and pre-ride line footage from the master laser discs to a VHS tape and sold bootleg copies of it. He was later fired and arrested, but, copies can still be found in online auctions, and some footage has been posted on YouTube. As a result, Universal announced in 2007 that they might soon release an official DVD of the footage, similar to what took place for the Shrek 4-D attraction.

According to Bob Gale in a recent interview after a screening of Back To The Future, he said that he talked to Universal, and it is a possibility that the Back To The Future Ride footage and all the line and pre-show videos will be included as extra bonus feature on the upcoming Blu-Ray release of the Back To The Future trilogy^.

Universal recently announced the inclusion of the entire footage of Back to the Future: The Ride into its upcoming rerelease of the Back to the Future DVD as part of a second bonus disc^. The DVD rerelease is scheduled for February 10, 2009.

Visitors to the Institute wait outside the facility, where TV monitors showed a live video feed of Doc. Brown in 2015, as well as videos detailing Brown’s inventions.

Pre-show

Riders enter the ride as “volunteers” for a time travel experiment at Emmett Brown’s fictional Institute of Future Technology. Brown explains that the plan is for them to travel one day into the future, but that caution must be exercised as Biff Tannen, who was graduated from the Hill Valley High School in 1955, has escaped his time period and is now running amok in the space-time continuum.

Once inside, Brown reveals some of the inventions he has been working on, including his “crowning achievement” – an 8-passenger De Lorean time machine (also a convertible), which is what the riders will be using in the experiment. Unbeknownst to Brown, however, Tannen has infiltrated the Institute – he appears to the riders, asking for assistance in finding Brown’s time machine. The receptionist then announced that the pre-flght system checks is in progress and afterwards, she told the visitors to stand by for an announcement from Dr. Brown.

Tannen traps Brown in his office, and it is revealed that he escaped 1955 when employees of Brown took the Time Train to 1955 for an experiment; Tannen stowed away when they make the return journey. He steals the time machine and vanishes into time. Frantic, Brown pleads with the visitors to assist him and announced that the only way to bring Biff back to the present day is to accelerate to 88 miles per hour and bump him; they enter the 8-passenger time vehicle, led by one of Doc Brown’s Assistants, after going over final safety instructions (safety tips posed by the receptionist who concludes by saying, “Enjoy your flight!”) (with some helpful advice from Brown saying that the time vehicle Biff had stolen has a homing device, that way wherever Biff may be, the 8-passenger vehicle will pin-point to that exact location). They then follow Tannen into time.

When the doors of the time machine closed, Dr. Brown uses his remote control to control the time machine, hovers it, and accelerates to 88 miles per hour (with electric sparks coming from the time machine and speeding through the open door and blasting through the vortex) and the ride begins.

First, Biff leads the riders to Hill Valley in 2015, where they chase him through town. They smash into neon signs, flying over neighborhoods and the town square, the chase culminating at the iconic clock tower. He then departs for the ice age.

The riders follow, and slowly lower into the icy caverns of the ice age. Biff honks his horn, causing an avalanche that damages the riders’ vehicle. Flying out of the caverns, the car sees Biff shoot away into time, but their own engine has failed, and begins to plummet down a waterfall. Brown manages to restart the vehicle, accelerating backward and through time into the Cretaceous Period.

Upon arriving, the clock display on the De Lorean’s dashboard blinks 12:00, as a reference to a videocassette recorder that has lost power. The riders follow Biff’s vehicle into a dormant volcano in which a Tyrannosaurus is discovered. Tannen goads it into attacking the riders, who barely escape. The dinosaur strikes Tannen’s car, sending it flying out of control; the dinosaur then swallows the riders’ car, but spits it out mere seconds later. The riders then drop down onto a lava river to see Biff’s De Lorean, now damaged and unable to maneuver, moving down an active lava flow toward the edge of a cliff. As both vehicles plunge over the edge, the riders’ car accelerates to time travel speed and bumps Tannen’s, sending both of them back to the original point of departure – the present, at the Institute of Future Technology, where Biff gets out, thanks the riders and Dr. Brown (although it’s quite obvious that he wasn’t happy he was captured), but is soon grabbed by security and taken away.

Riders exit the vehicle, as Brown thanks them and reminds them that “the future is what you make it!”

Back to the Future Part III is the third installment of the Back to the Future trilogy. The film is a science fiction western, using the time travel premise of the series to take Marty McFly (Michael J. Fox) and Dr. Emmett Brown (Christopher Lloyd) back to the Old West of 1885.

After lightning strikes the clock tower and sends the Back to the Future Marty back to 1985, Marty McFly (Michael J Fox), who is stranded in 1955, takes “Doc” Emmett Brown (Christopher Lloyd) home. He explains to the Doc of that era that Doc’s future self and the DeLorean time machine were accidentally sent back to the year 1885. Marty learns from a letter written by Doc in 1885, that the DeLorean is hidden in an old mineshaft. The letter instructs Marty to find the car, return to 1985, and then destroy it in order to prevent further disruption of the space-time continuum.

With the help of the Doc of 1955, Marty retrieves the DeLorean. In the process, he discovers a tombstone which leads him to learn that Doc was killed in 1885 by Buford “Mad Dog” Tannen, just seven days after having written the letter. Ignoring Doc’s urging to return to 1985, Marty decides that he must save Doc, who had no idea he would be killed days later. Marty takes the DeLorean back to 1885, and arrives in the middle of a skirmish between a group of Native Americans and the United States cavalry, resulting in the DeLorean’s fuel line being ruptured. Marty reunites with Doc, who agrees to leave when he learns of his upcoming fate. Doc sees Marty’s photograph of his tombstone and concludes from the inscription that he was to have fallen in love with a woman named “Clara”. Learning that the new schoolmarm he has promised to pick up is named Clara Clayton, Doc decides to leave without meeting her.

However, the ruptured fuel line has left the DeLorean’s gas tank completely empty; and the DeLorean cannot reach 88 miles per hour without gasoline. After several failed attempts to accelerate the car through alternate means, Doc decides to push the DeLorean up to speed with a steam locomotive, but finds that the only track straight enough ends in an incomplete bridge over a deep ravine. The car will have to reach 88 miles per hour before reaching the bridge, so that it can travel to 1985 where the bridge is completed. As they scout the location, they save a woman from falling into the ravine on a runaway carriage, only to discover that she is Clara Clayton. She and Doc immediately become enamoured with each other.

Marty as “Clint Eastwood“

At a festival dedicating the newly constructed clock tower, Buford attempts to kill Doc, only to be thwarted by Marty. Marty, however, is goaded into a gun duel after Buford calls him “yellow”. With Doc’s original death averted, his name disappears from the tombstone in the photograph, but the date remains. Doc warns Marty that his name may end up on it if he chooses to meet up with Buford. Still infatuated with Clara, the Doc expresses his desire to stay with her in 1885, but Marty talks him out of it. Doc decides to say goodbye to her and, when pressed, tells her that he’s from the future. Thinking this an obvious lie, Clara angrily slaps him in rejection and starts to cry as Doc heads to the town saloon to get drunk. Marty convinces him to leave the saloon, but not before Buford shows up and insists that it’s time for the showdown. Marty is forced to participate and defeats Buford by using a stove cover as a bullet-proof shield. Following the duel, Buford is arrested for having committed a robbery the previous day. Clara, meanwhile, hears about how heartbroken the Doc was when she rejected him and sets off to find him.

Doc and Marty manage to hijack the locomotive and start to push the DeLorean; Marty waits in the DeLorean while Doc remains on the train to add specially-created logs to the boiler that will overheat it and increase its speed. Clara catches up with the locomotive on horse and climbs aboard as Doc makes his way to the DeLorean. Seeing Clara in the cab, he is forced to return for her, and manages to fly off with her on the hoverboard just as the DeLorean reaches 88 miles per hour and transports Marty back to 1985 alone. The locomotive, which subsequently runs past the track, falls into the ravine and explodes.

The Doc and family return from the past

As planned in the parallel year 1985, Marty coasts safely across the ravine bridge, but he immediately encounters a modern-day diesel locomotive bearing down on him. Marty escapes, but the DeLorean is smashed to pieces. Marty picks Jennifer up at her house where he left her in Part II, and having learned his lesson back in 1885, refuses to take part in a drag race with Needles, who calls him ‘chicken’. This causes him to avoid the automobile accident which resulted in the ruined future depicted in the previous film. Marty takes Jennifer to the site of the destroyed DeLorean, where he accepts that it is what Doc wanted. At that moment, however, a time machine built out of a locomotive appears. The door opens to reveal Doc, Clara and their two sons, who are named Jules and Verne (before appearing in Back to the Future: The Animated Series) after the author Jules Verne. As Doc prepares to leave again, Marty asks if they plan to go to the future. Doc replies that they’ve already been there, and the train lifts off from the ground and flies off into time.