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UTEC (University of Toronto Electronic Computer Mark I) was a computer built at the University of Toronto (UofT) in the early 1950s. It was the first computer in Canada, one of the first working computers in the world, although only built in a prototype form while awaiting funding for expansion into a full-scale version. This funding was eventually used to purchase a surplus Manchester Mark 1 from Ferranti in the UK instead, and UTEC quickly disappeared.

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100-531: Immediately after the end of World War II several members of the UofT staff met informally as the Committee on Computing Machines to discuss their computation needs over the next few years. In 1946 a small $ 1,000 grant was used to send one of the group's members to tour several US research labs to see their progress on computers and try to see what was possible given UofT's likely funding. Due to UofT's preeminent position in

200-637: A Neutrality Pact in April 1941, and Japan adopted the doctrine of Nanshin-ron , promoted by the Navy, which took its focus southward and eventually led to war with the United States and the Western Allies. In Europe, Germany and Italy were becoming more aggressive. In March 1938, Germany annexed Austria , again provoking little response from other European powers. Encouraged, Hitler began pressing German claims on

300-564: A cautious French probe into the Saarland . The Western Allies also began a naval blockade of Germany , which aimed to damage the country's economy and war effort. Germany responded by ordering U-boat warfare against Allied merchant and warships, which would later escalate into the Battle of the Atlantic . On 8 September, German troops reached the suburbs of Warsaw . The Polish counter-offensive to

400-453: A "spring loaded and air supported shoe for poising a magnetic head above a rapidly rotating magnetic drum." Flying heads became standard in drums and hard disk drives . Magnetic drum units used as primary memory were addressed by word. Drum units used as secondary storage were addressed by block. Several modes of block addressing were possible, depending on the device. Some devices were divided into logical cylinders, and addressing by track

500-431: A 1949 visit by Freddie Williams led to them abandoning this work and moving to Williams tubes instead. Given the current level of funding a full-scale machine was not possible, so it was decided to build a smaller machine to test out the various components. Williams tubes would store 256 12-bit words, with instructions using 3-bits of a word leaving 9-bits for addressing (allowing up to 512 words of memory). Parts of

600-678: A copy of Bell Labs ' Model 6 relay -based machine, which they had seen earlier. However, when they finally decided to go ahead with the project in August 1948, Northern Electric (Bell's arm in Canada) informed them they would charge $ 25,000 ($ 332839 in 2024) to license the Model 6 design. At a meeting with the NRC in March 1949, the NRC turned down their request for additional funding for the license, and instead suggested that

700-514: A head just in time. This method of timing-compensation, called the "skip factor" or " interleaving ", was used for many years in storage memory controllers. Tauschek's original drum memory (1932) had a capacity of about 500,000 bits (62.5 kilobytes ). One of the earliest functioning computers to employ drum memory was the Atanasoff–Berry computer (1942). It stored 3,000 bits; however, it employed capacitance rather than magnetism to store

800-415: A large metal cylinder, coated on the outside surface with a ferromagnetic recording material. It could be considered the precursor to the hard disk drive (HDD), but in the form of a drum (cylinder) rather than a flat disk. In most designs, one or more rows of fixed read-write heads ran along the long axis of the drum, one for each track. The drum's controller simply selected the proper head and waited for

900-514: A pretext to initiate the invasion. The first German attack of the war came against the Polish defences at Westerplatte . The United Kingdom responded with an ultimatum for Germany to cease military operations, and on 3 September, after the ultimatum was ignored, Britain and France declared war on Germany. During the Phoney War period, the alliance provided no direct military support to Poland, outside of

1000-765: A pretext to worsen relations. On 29 August, Hitler demanded that a Polish plenipotentiary immediately travel to Berlin to negotiate the handover of Danzig , and to allow a plebiscite in the Polish Corridor in which the German minority would vote on secession. The Poles refused to comply with the German demands, and on the night of 30–31 August in a confrontational meeting with the British ambassador Nevile Henderson , Ribbentrop declared that Germany considered its claims rejected. On 1 September 1939, Germany invaded Poland after having staged several false flag border incidents as

1100-554: A second bank of memory to bring it to the full 512 words. Libraries added math functions for 12-, 24-, 36- and 48-bit math. A basic 12-bit addition took about 240 microseconds, multiplication about 18 milliseconds. With the basic system up and running, attention turned to a "full sized" version. This machine would use a 44-bit word with 1,024 words of memory backed up with a 10,000 word magnetic drum to be supplied by Ferranti Canada . A new math unit would operate on an entire word in parallel, instead of bit-serial as with most machines of

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1200-469: A secret protocol that defined German and Soviet "spheres of influence" (western Poland and Lithuania for Germany; eastern Poland , Finland, Estonia , Latvia and Bessarabia for the Soviet Union), and raised the question of continuing Polish independence. The pact neutralised the possibility of Soviet opposition to a campaign against Poland and assured that Germany would not have to face the prospect of

1300-695: A similar pact and rejected ceding part of its territory to the Soviet Union. The Soviet Union invaded Finland in November 1939, and was subsequently expelled from the League of Nations for this crime of aggression. Despite overwhelming numerical superiority, Soviet military success during the Winter War was modest, and the Finno-Soviet war ended in March 1940 with some Finnish concessions of territory . In June 1940,

1400-519: A two-front war, as it had in World War   I. Immediately afterwards, Hitler ordered the attack to proceed on 26 August, but upon hearing that the United Kingdom had concluded a formal mutual assistance pact with Poland and that Italy would maintain neutrality, he decided to delay it. In response to British requests for direct negotiations to avoid war, Germany made demands on Poland, which served as

1500-588: The Anglo-German Naval Agreement and the German–Polish declaration of non-aggression . The situation became a crisis in late August as German troops continued to mobilise against the Polish border. On 23 August the Soviet Union signed a non-aggression pact with Germany, after tripartite negotiations for a military alliance between France, the United Kingdom, and Soviet Union had stalled. This pact had

1600-453: The Axis powers . Nearly all the world's countries —including all the great powers —participated, with many investing all available economic, industrial, and scientific capabilities in pursuit of total war , blurring the distinction between military and civilian resources. Tanks and aircraft played major roles , with the latter enabling the strategic bombing of population centres and delivery of

1700-662: The British Empire , with fighting in the Balkans , Mediterranean, and Middle East , the aerial Battle of Britain and the Blitz , and naval Battle of the Atlantic . Through a series of campaigns and treaties, Germany took control of much of continental Europe and formed the Axis alliance with Italy , Japan , and other countries. In June 1941, Germany led the European Axis in an invasion of

1800-566: The German Revolution of 1918–1919 , and a democratic government, later known as the Weimar Republic , was created. The interwar period saw strife between supporters of the new republic and hardline opponents on both the political right and left. Italy, as an Entente ally, had made some post-war territorial gains; however, Italian nationalists were angered that the promises made by the United Kingdom and France to secure Italian entrance into

1900-814: The German invasion of Poland and the United Kingdom and France 's declaration of war on Germany two days later on 3 September 1939. Dates for the beginning of the Pacific War include the start of the Second Sino-Japanese War on 7 July 1937, or the earlier Japanese invasion of Manchuria , on 19 September 1931. Others follow the British historian A. J. P. Taylor , who stated that the Sino-Japanese War and war in Europe and its colonies occurred simultaneously, and

2000-486: The IBM 650 (1954), initially had up to 2,000 10-digit words, about 17.5 kilobytes , of drum memory (later doubled to 4,000 words, about 35 kilobytes, in the Model 4). In BSD Unix and its descendants, /dev/drum was the name of the default virtual memory (swap) device, deriving from the historical use of drum secondary-storage devices as backup storage for pages in virtual memory . Magnetic drum memory units were used in

2100-567: The Italian mainland , and Allied offensives in the Pacific—cost the Axis powers their initiative and forced them into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France at Normandy , while the Soviet Union regained its territorial losses and pushed Germany and its allies westward. At the same time, Japan suffered reversals in mainland Asia, while the Allies crippled

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2200-537: The Japanese Navy and captured key islands . The war in Europe concluded with the liberation of German-occupied territories ; the invasion of Germany by the Western Allies and the Soviet Union, culminating in the fall of Berlin to Soviet troops; Hitler's suicide ; and the German unconditional surrender on 8 May 1945 . Following the refusal of Japan to surrender on the terms of the Potsdam Declaration ,

2300-682: The League of Nations as a force to preserve peace. Both Italy and Ethiopia were member nations, but the League did little when the former clearly violated Article X of the League's Covenant . The United Kingdom and France supported imposing sanctions on Italy for the invasion, but the sanctions were not fully enforced and failed to end the Italian invasion. Italy subsequently dropped its objections to Germany's goal of absorbing Austria . When civil war broke out in Spain, Hitler and Mussolini lent military support to

2400-693: The Nationalist rebels , led by General Francisco Franco . Italy supported the Nationalists to a greater extent than the Nazis: Mussolini sent more than 70,000 ground troops, 6,000 aviation personnel, and 720 aircraft to Spain. The Soviet Union supported the existing government of the Spanish Republic . More than 30,000 foreign volunteers, known as the International Brigades , also fought against

2500-677: The Rome–Berlin Axis . A month later, Germany and Japan signed the Anti-Comintern Pact , which Italy joined the following year. The Kuomintang (KMT) party in China launched a unification campaign against regional warlords and nominally unified China in the mid-1920s, but was soon embroiled in a civil war against its former Chinese Communist Party (CCP) allies and new regional warlords . In 1931, an increasingly militaristic Empire of Japan , which had long sought influence in China as

2600-581: The Soviet–Japanese Neutrality Pact in April 1941. By contrast, the Germans were steadily making preparations for an attack on the Soviet Union, massing forces on the Soviet border. Hitler believed that the United Kingdom's refusal to end the war was based on the hope that the United States and the Soviet Union would enter the war against Germany sooner or later. On 31 July 1940, Hitler decided that

2700-580: The Stresa Front in April 1935 in order to contain Germany, a key step towards military globalisation ; however, that June, the United Kingdom made an independent naval agreement with Germany, easing prior restrictions. The Soviet Union, concerned by Germany's goals of capturing vast areas of Eastern Europe , drafted a treaty of mutual assistance with France. Before taking effect, though, the Franco-Soviet pact

2800-689: The Sudetenland , an area of Czechoslovakia with a predominantly ethnic German population. Soon the United Kingdom and France followed the appeasement policy of British Prime Minister Neville Chamberlain and conceded this territory to Germany in the Munich Agreement , which was made against the wishes of the Czechoslovak government, in exchange for a promise of no further territorial demands. Soon afterwards, Germany and Italy forced Czechoslovakia to cede additional territory to Hungary, and Poland annexed

2900-682: The Tanggu Truce was signed in 1933. Thereafter, Chinese volunteer forces continued the resistance to Japanese aggression in Manchuria , and Chahar and Suiyuan . After the 1936 Xi'an Incident , the Kuomintang and CCP forces agreed on a ceasefire to present a united front to oppose Japan. The Second Italo-Ethiopian War was a brief colonial war that began in October 1935 and ended in May 1936. The war began with

3000-568: The Trans-Olza region of Czechoslovakia. Although all of Germany's stated demands had been satisfied by the agreement, privately Hitler was furious that British interference had prevented him from seizing all of Czechoslovakia in one operation. In subsequent speeches Hitler attacked British and Jewish "war-mongers" and in January 1939 secretly ordered a major build-up of the German navy to challenge British naval supremacy. In March 1939, Germany invaded

3100-554: The Treaty of Craiova . The loss of one-third of Romania's 1939 territory caused a coup against King Carol II, turning Romania into a fascist dictatorship under Marshal Ion Antonescu , with a course set towards the Axis in the hopes of a German guarantee. Meanwhile, German-Soviet political relations and economic co-operation gradually stalled, and both states began preparations for war. In April 1940, Germany invaded Denmark and Norway to protect shipments of iron ore from Sweden , which

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3200-505: The UNIVAC FASTRAND series of drums. Drums were displaced as primary computer memory by magnetic core memory , which offered a better balance of size, speed, cost, reliability and potential for further improvements. Drums were then replaced by hard disk drives for secondary storage , which were both less expensive and offered denser storage. The manufacturing of drums ceased in the 1970s. A drum memory or drum storage unit contained

3300-723: The United Kingdom and France to declare war on Germany. Poland was divided between Germany and the Soviet Union under the Molotov–Ribbentrop Pact , in which they had agreed on " spheres of influence " in Eastern Europe. In 1940, the Soviets annexed the Baltic states and parts of Finland and Romania . After the fall of France in June 1940, the war continued mainly between Germany and

3400-685: The University of Manchester . An ERA drum was the internal memory for the ATLAS-I computer delivered to the U.S. Navy in October 1950 and later sold commercially as the ERA 1101 and UNIVAC 1101 . Through mergers , ERA became a division of UNIVAC shipping the Series 1100 drum as a part of the UNIVAC File Computer in 1956; each drum stored 180,000 6-bit characters (135 kilobytes). The first mass-produced computer,

3500-683: The Wehrmacht rapidly advanced to the Channel and cut off the Allied forces in Belgium, trapping the bulk of the Allied armies in a cauldron on the Franco-Belgian border near Lille. The United Kingdom was able to evacuate a significant number of Allied troops from the continent by early June, although they had to abandon almost all their equipment. On 10 June, Italy invaded France , declaring war on both France and

3600-612: The aftermath of World War I and the rise of fascism in Europe and militarism in Japan . Key events leading up to the war included Japan's invasion of Manchuria , the Spanish Civil War , the outbreak of the Second Sino-Japanese War , and Germany's annexations of Austria and the Sudetenland . World War II is generally considered to have begun on 1 September 1939, when Nazi Germany , under Adolf Hitler , invaded Poland , prompting

3700-595: The only two nuclear weapons ever used in war. World War II was the deadliest conflict in history, resulting in 70 to 85 million deaths , more than half being civilians. Millions died in genocides , including the Holocaust of European Jews, as well as from massacres, starvation, and disease. Following the Allied powers' victory, Germany , Austria , Japan , and Korea were occupied, and war crimes tribunals were conducted against German and Japanese leaders . The causes of World War II included unresolved tensions in

3800-404: The reunification of East and West Germany to take place and resolved most post–World War   II issues. No formal peace treaty between Japan and the Soviet Union was ever signed, although the state of war between the two countries was terminated by the Soviet–Japanese Joint Declaration of 1956 , which also restored full diplomatic relations between them. World War I had radically altered

3900-409: The Allies were attempting to cut off . Denmark capitulated after six hours , and despite Allied support , Norway was conquered within two months. British discontent over the Norwegian campaign led to the resignation of Prime Minister Neville Chamberlain , who was replaced by Winston Churchill on 10   May 1940. On the same day, Germany launched an offensive against France . To circumvent

4000-400: The Axis war against the Soviet Union, in Romania's case partially to recapture territory ceded to the Soviet Union . In early June 1940, the Italian Regia Aeronautica attacked and besieged Malta , a British possession. From late summer to early autumn, Italy conquered British Somaliland and made an incursion into British-held Egypt . In October, Italy attacked Greece , but the attack

4100-421: The Blitz , but largely ended in May 1941 after failing to significantly disrupt the British war effort. Using newly captured French ports, the German Navy enjoyed success against an over-extended Royal Navy , using U-boats against British shipping in the Atlantic . The British Home Fleet scored a significant victory on 27   May 1941 by sinking the German battleship Bismarck . In November 1939,

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4200-417: The Canadian research world, the tour was also followed by members of the Canadian Research Council. In January 1947 the committee delivered a report suggesting the creation of a formal Computing Center , primarily as a service bureau to provide computing services both to the university and commercial interests, as well as the nucleus of a research group into computing machinery. Specifically they recommended

4300-405: The Center invest in a fully electronic computer, upping the yearly grants to $ 50,000 to that end. This turned out to be a major "win" - relay based computers quickly disappeared, and electronic systems proved themselves quickly. Beatrice Helen Worsley and Perham Stanley, two graduate students working at the Computation Center, were sent to Cambridge University to work with Maurice Wilkes who

4400-408: The Committee eventually selecting Kelly Gotlieb to run it. Additional funding followed in February 1948 with a $ 20,000 a year grant from a combined pool set up by the DRB and NRC. Although this was less than was hoped for, the IBM machinery was soon in place and being used to calculate several tables for Atomic Energy of Canada Limited (AECL). Additionally a small version of the differential analyzer

4500-447: The Computation Center would buy the Mark I, another $ 150,000 would be made available to continue development of the UTEC, and an equal amount if they decided to actually build it. This sort of deal one does not refuse, and plans to ship the Mark I to Toronto were soon underway. The machine arrived on April 30, 1952, at the time it was major news. Named Ferut ( Ferranti, University of Toronto ) by Worsley shortly before it arrived, it took

4600-405: The European Axis declaring war on the US. Japan conquered much of coastal China and Southeast Asia , but its advances in the Pacific were halted in mid-1942 after its defeat in the naval Battle of Midway ; Germany and Italy were defeated in North Africa and at Stalingrad in the Soviet Union. Key setbacks in 1943—including German defeats on the Eastern Front, the Allied invasions of Sicily and

4700-508: The Ferranti engineers several months to set it up. Even then it became one of the first "large" machines to start operation in North America. Ferut would go on to be a major research system in Canada, being used by Ontario Hydro to calculate changes in water levels due to the opening of the St. Lawrence Seaway , various development of the groundbreaking ReserVec system with Ferranti Canada for Trans Canada Airlines , and even rental of time for commercial seismic data processing. The arrival of

4800-410: The Ferut also spelled the death of the UTEC project. Even with the additional funding, most of the engineers quickly drifted to the Ferut machine. World War II Asia-Pacific Mediterranean and Middle East Other campaigns Coups World War II or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between two coalitions: the Allies and

4900-410: The French possessions of Syria and Lebanon , assisted by the Free French . With the situation in Europe and Asia relatively stable, Germany, Japan, and the Soviet Union made preparations for war. With the Soviets wary of mounting tensions with Germany, and the Japanese planning to take advantage of the European War by seizing resource-rich European possessions in Southeast Asia , the two powers signed

5000-426: The Germans, and the last large operational unit of the Polish Army surrendered on 6   October . Despite the military defeat, Poland never surrendered; instead, it formed the Polish government-in-exile and a clandestine state apparatus remained in occupied Poland. A significant part of Polish military personnel evacuated to Romania and Latvia; many of them later fought against the Axis in other theatres of

5100-450: The Nationalists. Both Germany and the Soviet Union used this proxy war as an opportunity to test in combat their most advanced weapons and tactics. The Nationalists won the civil war in April 1939; Franco, now dictator, remained officially neutral during World War   II but generally favoured the Axis . His greatest collaboration with Germany was the sending of volunteers to fight on the Eastern Front . In July 1937, Japan captured

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5200-452: The Royal Navy putting three Italian battleships out of commission after a carrier attack at Taranto , and neutralising several more warships at the Battle of Cape Matapan . Italian defeats prompted Germany to deploy an expeditionary force to North Africa; at the end of March 1941, Rommel 's Afrika Korps launched an offensive which drove back Commonwealth forces. In less than a month, Axis forces advanced to western Egypt and besieged

5300-423: The Soviet Union occupied the entire territories of Estonia, Latvia and Lithuania, as well as the Romanian regions of Bessarabia, Northern Bukovina, and the Hertsa region . In August 1940, Hitler imposed the Second Vienna Award on Romania which led to the transfer of Northern Transylvania to Hungary. In September 1940, Bulgaria demanded Southern Dobruja from Romania with German and Italian support, leading to

5400-421: The Soviet Union , opening the Eastern Front and initially making large territorial gains. Japan aimed to dominate East Asia and the Asia-Pacific , and by 1937 was at war with the Republic of China . In December 1941, Japan attacked American and British territories in Southeast Asia and the Central Pacific , including Pearl Harbor in Hawaii , which resulted in the US and the UK declaring war against Japan, and

5500-418: The Soviet Union and Mongolia . The Japanese doctrine of Hokushin-ron , which emphasised Japan's expansion northward, was favoured by the Imperial Army during this time. This policy would prove difficult to maintain in light of the Japanese defeat at Khalkin Gol in 1939, the ongoing Second Sino-Japanese War and ally Nazi Germany pursuing neutrality with the Soviets. Japan and the Soviet Union eventually signed

5600-575: The Soviet Union should be eliminated and aimed for the conquest of Ukraine , the Baltic states and Byelorussia . However, other senior German officials like Ribbentrop saw an opportunity to create a Euro-Asian bloc against the British Empire by inviting the Soviet Union into the Tripartite Pact. In November 1940, negotiations took place to determine if the Soviet Union would join the pact. The Soviets showed some interest but asked for concessions from Finland, Bulgaria, Turkey, and Japan that Germany considered unacceptable. On 18 December 1940, Hitler issued

5700-402: The US dropped the first atomic bombs on Hiroshima and Nagasaki on 6 and 9 August. Faced with an imminent invasion of the Japanese archipelago , the possibility of further atomic bombings, and the Soviet declaration of war against Japan and its invasion of Manchuria , Japan announced its unconditional surrender on 15 August and signed a surrender document on 2 September 1945 , marking

5800-424: The United Kingdom and France guaranteed their support for Polish independence ; when Italy conquered Albania in April 1939, the same guarantee was extended to the Kingdoms of Romania and Greece . Shortly after the Franco - British pledge to Poland, Germany and Italy formalised their own alliance with the Pact of Steel . Hitler accused the United Kingdom and Poland of trying to "encircle" Germany and renounced

5900-489: The United Kingdom attacked on 3   July in an attempt to prevent its seizure by Germany. The air Battle of Britain began in early July with Luftwaffe attacks on shipping and harbours . The German campaign for air superiority started in August but its failure to defeat RAF Fighter Command forced the indefinite postponement of the proposed German invasion of Britain . The German strategic bombing offensive intensified with night attacks on London and other cities in

6000-401: The United Kingdom. The Germans turned south against the weakened French army, and Paris fell to them on 14   June. Eight days later France signed an armistice with Germany ; it was divided into German and Italian occupation zones , and an unoccupied rump state under the Vichy Regime , which, though officially neutral, was generally aligned with Germany. France kept its fleet, which

6100-473: The United States was assisting China and the Western Allies, and had amended the Neutrality Act to allow "cash and carry" purchases by the Allies. In 1940, following the German capture of Paris, the size of the United States Navy was significantly increased . In September the United States further agreed to a trade of American destroyers for British bases . Still, a large majority of the American public continued to oppose any direct military intervention in

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6200-434: The Yellow River ; this manoeuvre bought time for the Chinese to prepare their defences at Wuhan , but the city was taken by October. Japanese military victories did not bring about the collapse of Chinese resistance that Japan had hoped to achieve; instead, the Chinese government relocated inland to Chongqing and continued the war. In the mid-to-late 1930s, Japanese forces in Manchukuo had sporadic border clashes with

6300-404: The assembler, e.g., Symbolic Optimal Assembly Program (SOAP)—positioned code on the drum in such a way as to reduce the amount of time needed for the next instruction to rotate into place under the head. They did this by timing how long it would take after loading an instruction for the computer to be ready to read the next one, then placing that instruction on the drum so that it would arrive under

6400-405: The capital Nanking in December 1937. After the fall of Nanking, tens or hundreds of thousands of Chinese civilians and disarmed combatants were murdered by the Japanese . In March 1938, Nationalist Chinese forces won their first major victory at Taierzhuang , but then the city of Xuzhou was taken by the Japanese in May. In June 1938, Chinese forces stalled the Japanese advance by flooding

6500-403: The conflict well into 1941. In December 1940, Roosevelt accused Hitler of planning world conquest and ruled out any negotiations as useless, calling for the United States to become an " arsenal of democracy " and promoting Lend-Lease programmes of military and humanitarian aid to support the British war effort; Lend-Lease was later extended to the other Allies, including the Soviet Union after it

6600-410: The creation of a " New Roman Empire ". Adolf Hitler , after an unsuccessful attempt to overthrow the German government in 1923, eventually became the Chancellor of Germany in 1933 when Paul von Hindenburg and the Reichstag appointed him. Following Hindenburg's death in 1934, Hitler proclaimed himself Führer of Germany and abolished democracy, espousing a radical, racially motivated revision of

6700-531: The data to appear under it as the drum turned ( rotational latency ). Not all drum units were designed with each track having its own head. Some, such as the English Electric DEUCE drum and the UNIVAC FASTRAND had multiple heads moving a short distance on the drum in contrast to modern HDDs, which have one head per platter surface. In November 1953 Hagen published a paper disclosing "air floating" of magnetic heads in an experimental sheet metal drum. A US patent filed in January 1954 by Baumeister of IBM disclosed

6800-499: The directive to prepare for an invasion of the Soviet Union. Magnetic drum Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria . Drums were widely used in the 1950s and into the 1960s as computer memory . Many early computers, called drum computers or drum machines, used drum memory as the main working memory of the computer. Some drums were also used as secondary storage as for example various IBM drum storage drives and

6900-616: The dissolution of the Austro-Hungarian, Ottoman, and Russian Empires. To prevent a future world war, the League of Nations was established in 1920 by the Paris Peace Conference . The organisation's primary goals were to prevent armed conflict through collective security, military, and naval disarmament , as well as settling international disputes through peaceful negotiations and arbitration. Despite strong pacifist sentiment after World War   I , irredentist and revanchist nationalism had emerged in several European states. These sentiments were especially marked in Germany because of

7000-421: The end of May completed the German conquest of the Balkans. Partisan warfare subsequently broke out against the Axis occupation of Yugoslavia , which continued until the end of the war. In the Middle East in May, Commonwealth forces quashed an uprising in Iraq which had been supported by German aircraft from bases within Vichy-controlled Syria . Between June and July, British-led forces invaded and occupied

7100-409: The end of the war. World War II changed the political alignment and social structure of the world, and it set the foundation of international relations for the rest of the 20th century and into the 21st century. The United Nations was established to foster international cooperation and prevent conflicts, with the victorious great powers—China, France, the Soviet Union, the UK, and the US—becoming

7200-526: The era, dramatically improving performance so that an addition would take only 20 microseconds and a multiply about 200—faster than the prototype at addition even on its much smaller word size. Success of the UTEC created intense demand within the Canadian research establishment to start construction of the full scale follow-on. The funding pool was increased to $ 300,000 to cover development and construction. While UTEC

7300-617: The first step of what its government saw as the country's right to rule Asia , staged the Mukden incident as a pretext to invade Manchuria and establish the puppet state of Manchukuo . China appealed to the League of Nations to stop the Japanese invasion of Manchuria. Japan withdrew from the League of Nations after being condemned for its incursion into Manchuria. The two nations then fought several battles, in Shanghai , Rehe and Hebei , until

7400-843: The former Chinese imperial capital of Peking after instigating the Marco Polo Bridge incident , which culminated in the Japanese campaign to invade all of China. The Soviets quickly signed a non-aggression pact with China to lend materiel support, effectively ending China's prior cooperation with Germany . From September to November, the Japanese attacked Taiyuan , engaged the Kuomintang Army around Xinkou , and fought Communist forces in Pingxingguan . Generalissimo Chiang Kai-shek deployed his best army to defend Shanghai , but after three months of fighting, Shanghai fell. The Japanese continued to push Chinese forces back, capturing

7500-599: The immediate renting of an IBM mechanical punched card -based calculator, building a simple differential analyzer , and the eventual purchase or construction of an electronic computer. The report noted that funding should be expected from both the National Research Council (NRC) and the Defense Research Board (DRB). The DRB soon provided a grant of $ 6,500 to set up the Computation Center, with

7600-457: The information. The outer surface of the drum was lined with electrical contacts leading to capacitors contained within. Magnetic drums were developed for the U.S. Navy by Engineering Research Associates (ERA) in 1946 and 1947. An experimental ERA study was completed and reported to the Navy on June 19, 1947. Other early drum storage device development occurred at Birkbeck College ( University of London ), Harvard University , IBM and

7700-512: The invasion of the Ethiopian Empire (also known as Abyssinia ) by the armed forces of the Kingdom of Italy ( Regno d'Italia ), which was launched from Italian Somaliland and Eritrea . The war resulted in the military occupation of Ethiopia and its annexation into the newly created colony of Italian East Africa ( Africa Orientale Italiana , or AOI); in addition it exposed the weakness of

7800-495: The machine quickly reached the AECL, who suggested that they use the $ 300,000 set aside for the "new" UTEC to purchase the Mark I instead. The Computation Center considered the Mark I to be inferior to their own design and rejected it, notably because it used a serial math unit like their prototype and would thus be much slower. The AECL was not terribly impressed but came up with a solution; if

7900-529: The machine were up and running quickly, with the math and logic units (the arithmetic logic unit in modern terminology) running by the autumn of 1950. Memory reliability proved to be a serious problem, as it was for all systems using the Williams tube concept, but Katz introduced shielding that improved things somewhat. The machine was declared fully operational on October 1, 1951. Over the next few months major efforts were made to increase reliability, as well as add

8000-497: The permanent members of its security council . The Soviet Union and the United States emerged as rival superpowers , setting the stage for the Cold War . In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia . Most countries whose industries had been damaged moved towards economic recovery and expansion . World War II began in Europe on 1 September 1939 with

8100-571: The political European map with the defeat of the Central Powers —including Austria-Hungary , Germany , Bulgaria , and the Ottoman Empire —and the 1917 Bolshevik seizure of power in Russia , which led to the founding of the Soviet Union. Meanwhile, the victorious Allies of World War I , such as France, Belgium, Italy, Romania, and Greece, gained territory, and new nation-states were created out of

8200-583: The port of Tobruk . By late March 1941, Bulgaria and Yugoslavia signed the Tripartite Pact ; however, the Yugoslav government was overthrown two days later by pro-British nationalists. Germany and Italy responded with simultaneous invasions of both Yugoslavia and Greece , commencing on 6 April 1941; both nations were forced to surrender within the month. The airborne invasion of the Greek island of Crete at

8300-693: The remainder of Czechoslovakia and subsequently split it into the German Protectorate of Bohemia and Moravia and a pro-German client state , the Slovak Republic . Hitler also delivered an ultimatum to Lithuania on 20 March 1939, forcing the concession of the Klaipėda Region , formerly the German Memelland . Greatly alarmed and with Hitler making further demands on the Free City of Danzig ,

8400-410: The significant territorial, colonial, and financial losses imposed by the Treaty of Versailles . Under the treaty, Germany lost around 13 percent of its home territory and all its overseas possessions , while German annexation of other states was prohibited, reparations were imposed, and limits were placed on the size and capability of the country's armed forces . The German Empire was dissolved in

8500-494: The start or prelude to World War II. The exact date of the war's end also is not universally agreed upon. It was generally accepted at the time that the war ended with the armistice of 15 August 1945 ( V-J Day ), rather than with the formal surrender of Japan on 2 September 1945, which officially ended the war in Asia . A peace treaty between Japan and the Allies was signed in 1951. A 1990 treaty regarding Germany's future allowed

8600-575: The strong Maginot Line fortifications on the Franco-German border, Germany directed its attack at the neutral nations of Belgium , the Netherlands , and Luxembourg . The Germans carried out a flanking manoeuvre through the Ardennes region, which was mistakenly perceived by the Allies as an impenetrable natural barrier against armoured vehicles. By successfully implementing new Blitzkrieg tactics,

8700-510: The two wars became World War II in 1941. Other proposed starting dates for World War II include the Italian invasion of Abyssinia on 3 October 1935. The British historian Antony Beevor views the beginning of World War   II as the Battles of Khalkhin Gol fought between Japan and the forces of Mongolia and the Soviet Union from May to September 1939. Others view the Spanish Civil War as

8800-504: The war were not fulfilled in the peace settlement. From 1922 to 1925, the Fascist movement led by Benito Mussolini seized power in Italy with a nationalist, totalitarian , and class collaborationist agenda that abolished representative democracy, repressed socialist, left-wing, and liberal forces, and pursued an aggressive expansionist foreign policy aimed at making Italy a world power, promising

8900-475: The war. Germany annexed western Poland and occupied central Poland ; the Soviet Union annexed eastern Poland ; small shares of Polish territory were transferred to Lithuania and Slovakia . On 6 October, Hitler made a public peace overture to the United Kingdom and France but said that the future of Poland was to be determined exclusively by Germany and the Soviet Union. The proposal was rejected and Hitler ordered an immediate offensive against France, which

9000-503: The west halted the German advance for several days, but it was outflanked and encircled by the Wehrmacht . Remnants of the Polish army broke through to besieged Warsaw . On 17 September 1939, two days after signing a cease-fire with Japan , the Soviet Union invaded Poland under the supposed pretext that the Polish state had ceased to exist. On 27 September, the Warsaw garrison surrendered to

9100-687: The world order , and soon began a massive rearmament campaign . France, seeking to secure its alliance with Italy, allowed Italy a free hand in Ethiopia , which Italy desired as a colonial possession. The situation was aggravated in early 1935 when the Territory of the Saar Basin was legally reunited with Germany, and Hitler repudiated the Treaty of Versailles, accelerated his rearmament programme, and introduced conscription. The United Kingdom, France and Italy formed

9200-614: Was invaded by Germany. The United States started strategic planning to prepare for a full-scale offensive against Germany. At the end of September 1940, the Tripartite Pact formally united Japan, Italy, and Germany as the Axis powers . The Tripartite Pact stipulated that any country—with the exception of the Soviet Union—that attacked any Axis Power would be forced to go to war against all three. The Axis expanded in November 1940 when Hungary , Slovakia , and Romania joined. Romania and Hungary later made major contributions to

9300-488: Was actually logical cylinder and track. The performance of a drum with one head per track is comparable to that of a disk with one head per track and is determined almost entirely by the rotational latency, whereas in an HDD with moving heads its performance includes a rotational latency delay plus the time to position the head over the desired track ( seek time ). In the era when drums were used as main working memory, programmers often did optimum programming —the programmer—or

9400-549: Was being built, a similar machine was under construction at Manchester University , known as the "Baby" . Once it started working the university signed an agreement with Ferranti (in the UK) to build a full-scale machine eventually known as the Mark I. The new machine was delivered to the university in February 1951, making it the first commercial computer, about one month earlier than the UNIVAC I

9500-401: Was completed by September 1948, although it appears to have seen little use. Preliminary work on an electronic computer also started about the same time with some experimental work in various circuit designs. However they also felt that in order to get a machine working quickly, a fully electronic design was simply too state of the art and had significant risk. Instead they considered building

9600-615: Was handed over to the US Census Bureau . Ferranti had high hopes for further sales of the machine, and were happy when an order was placed by the British Atomic Energy Authority for delivery in autumn of 1952. However the government changed hands while the machine was being built, and all government contracts over £100,000 were cancelled outright. This left a partially completed Mark I sitting at Ferranti, who became interested in unloading it as soon as possible. Word of

9700-448: Was in the process of completing the EDSAC . Worsley wrote the program that generated a table of squares, the first program to successfully run on EDSAC. Another two graduate students, Alf Ratz and Josef Kates had been studying circuitry for some time by this point, and turned their attention to computer memory systems. Their first attempts were with a novel system based on neon tubes , but

9800-452: Was postponed until the spring of 1940 due to bad weather. After the outbreak of war in Poland, Stalin threatened Estonia , Latvia , and Lithuania with military invasion, forcing the three Baltic countries to sign pacts allowing the creation of Soviet military bases in these countries; in October 1939, significant Soviet military contingents were moved there. Finland refused to sign

9900-811: Was repulsed with heavy Italian casualties; the campaign ended within months with minor territorial changes. To assist Italy and prevent Britain from gaining a foothold, Germany prepared to invade the Balkans, which would threaten Romanian oil fields and strike against British dominance of the Mediterranean. In December 1940, British Empire forces began counter-offensives against Italian forces in Egypt and Italian East Africa . The offensives were successful; by early February 1941, Italy had lost control of eastern Libya, and large numbers of Italian troops had been taken prisoner. The Italian Navy also suffered significant defeats, with

10000-602: Was required to go through the bureaucracy of the League of Nations, which rendered it essentially toothless. The United States, concerned with events in Europe and Asia, passed the Neutrality Act in August of the same year. Hitler defied the Versailles and Locarno Treaties by remilitarising the Rhineland in March 1936, encountering little opposition due to the policy of appeasement . In October 1936, Germany and Italy formed

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