Baixe Inglês Técnico e outras Notas de estudo em PDF para Engenharia Telemática, somente na Docsity! Técnicas de Leitura As técnicas de leitura, como o próprio nome diz, vão nos ajudar a ler um texto. Existem técnicas variadas, mas veremos as mais utilizadas. Ao ler um texto em Inglês, lembre-se de usar as técnicas aprendidas, elas vão ajudá-lo. O uso da gramática vai ajudar também. As principais técnicas são: a identificação de cognatos, de palavras repetidas e de pistas tipográficas. Ao lermos um texto vamos,ainda, apurar a idéia geral do texto (general comprehension) e utilizar duas outras técnicas bastante úteis: skimming e scanning. a) Cognatos Os cognatos são palavras muito parecidas com as palavras do Português. São as chamadas palavras transparentes. Existem também os falsos cognatos, que são palavras que achamos que é tal coisa, mas não é; os falsos cognatos são em menor número, estes nós veremos adiante. Como cognatos podemos citar: school (escola), telephone (telefone), car (carro), question (questão, pergunta), activity (atividade), training (treinamento)... Você mesmo poderá criar sua própria lista de cognatos! b) Palavras repetidas As palavras repetidas em um texto possuem um valor muito importante. Um autor não repete as palavras em vão. Se elas são repetidas, é porque são importantes dentro de texto. Muitas vezes para não repetir o mesmo termo, o autor utiliza sinônimos das mesmas palavras para não tornar o texto cansativo. c) Pistas tipográficas As pistas tipográficas são elementos visuais que nos auxiliam na compreensão do texto. Atenção com datas, números, tabelas, gráficas, figuras... São informações também contidas no texto. Os recursos de escrita também são pistas tipográficas. Por exemplo: • ... (três pontos) indicam a continuação de uma idéia que não está ali exposta; • negrito dá destaque a algum termo ou palavra; • itálico também destaca um termo, menos importante que o negrito; • ‘’ ‘’ (aspas) salientam a importância de alguma palavra; • ( ) (parênteses) introduzem uma idéia complementar ao texto. d) General Comprehension A idéia geral de um texto é obtida com o emprego das técnicas anteriores. Selecionando-se criteriosamente algumas palavras, termos e expressões no texto, poderemos chegar à idéia geral do texto. Por exemplo, vamos ler o trecho abaixo e tentar obter a “general comprehension” deste parágrafo: “Distance education takes place when a teacher and students are separated by physical distance, and technology (i.e., voice, video and data), often in concert with face-to-face communication, is used to bridge the instructional gap.” From: Engineering Outreach College of Engineering – University of Idaho A partir das palavras cognatas do texto (em negrito) podemos ter um a idéia geral do que se trata; vamos enumerar as palavras conhecidas (pelo menos as que são semelhantes ao Português): • distance education = educação a distancia • students = estudantes, alunos • separeted = separado • physical distance = distância física • technology = tecnologia • voice, video, data = voz, vídeo e dados (atenção: “data” não é data) • face-to-face communication = comunicação face-a-face • used = usado (a) • instructional = instrucional Então você poderia dizer que o texto trata sobre educação a distância; que esta ocorre quando os alunos estão separados fisicamente do professor; a tecnologia (voz, vídeo, dados) podem ser usados de forma instrucional. Você poderia ter esta conclusão sobre o texto mesmo sem ter muito conhecimento de Inglês. É claro que à medida que você for aprendendo, a sua percepção sobre o texto também aumentará. Há muitas informações que não são tão óbvias assim. e) Skimming “skim” em inglês é deslizar à superfície, desnatar (daí skimmed milk = leite desnatado), passar os olhos por. A técnica de “skimming” nos leva a ler um texto superficialmente. Utilizar esta técnica significa que precisamos ler cada sentença, mas sim passarmos os olhos por sobre o texto, lendo algumas frases aqui e ali, procurando reconhecer certas palavras e expressões que sirvam como ‘dicas’ na obtenção de informações sobre o texto. Às vezes não é necessário ler o texto em detalhes. Para usar esta técnica, precisamos nos valer dos nossos conhecimentos de Inglês também. Observe este trecho: “Using this integrated approach, the educator’s task is to carefully select among the technological options. The goal is to build a mix of instructional media, meeting the needs of the learner in a manner that is instructionally effective and economically prudent.” From: Engineering Outreach College of Engineering – University of Idaho Selecionando algumas expressões teremos: • integrated approach = abordagem (approach = abordagem, enfoque) integrada • educator’s task = tarefa (task = tarefa) do educador – ‘s significa posse = do • tecnological options = opções tecnológicas (tecnological é adjetivo) • goal = objetivo • a mix instrucional media = uma mistura de mídia instrucional. WARNINGS – Calls for attention for a matter which might lead to a damage of the oscilloscope itself or other instruments. The following symbols may be posted on the oscilloscope as well as indicated in this manual. “DANGER! HIGH VOLTAGE” – This symbol means that the item cannot be charged up to a hazardous high voltage and must not be touched with bare hands. “REFER TO THE CORRESPONDING SECTION” – This symbol means that relative explanations contained in other parts of the handbook should be consulted. CAUTION – Means a matter which can lead to electric shock hazards to the person who is operating the instrument or to damage of the instrument itself or other instruments. USE A 3-PIN PLUG - For the input of AC input cable, be sure to use a 3-pin type (one of the pins is used for safety grounding). AC LINE VOLTAGE – Be sure to operate the oscilloscope on an AC line voltage within is correct range. AC POWER CABLE – When replacing the AC plug of the AC power cable, be sure to replace it with a plug of the correct type and ratings, and to connector the GND, NEUTRAL and LIVE wires which are color colored as shown in figure below: Fig 1 AC POWER FUSE – Be sure to use a power fuse of the correct ratings. COVERS – This oscilloscope has hazardous high voltages internally. Do not remove the covers of the oscilloscope lest you should expose yourself to such high voltages. The covers should be removed only by qualified experts. FEATURES ( 1 ) Easy to operate – You can easily use major functions of the oscilloscope which employs a direct knob control system. ( 2 ) Compact and light – COR 5500U series is very compact and light for its sophisticated functions and reliable performance. This has become feasible through dexterous use of flush-mount components. ( 3 ) CRT readout – It displays various items of information on the CRT screen, providing you with powerful means for rapid but accurate measurements. ( 4 ) Comment display – You can display comments by using this feature. ( 5 ) Alternate magnified sweeps – This feature allows you to magnify readily any portion of the waveform you want to observe more closely. This time base can be magnified by 5,10 or 50 times. The Alternate Magnified Sweep mode, which runs a mains sweep and magnified sweep alternately, is also available. ( 6 ) Sampling rate up to 20 MS/s – Each channel has a 5 bit A/D converter, allowing you to store the single-shot data from both channels simultaneously. In single Trigger Mode, you can capture frequency components up to 5.7 MHz (when Curve Interpolation is used). ( 7 ) 4k words/ channel memory capacity – each channel has a 4k word memory, and resolutions of 400 points per one division horizontally. The stored and reproduced waveforms closely resemble the original analog ones. COR 5500U series has two 4k-word Saving Memory units. The memory units are internally backed up so that the data is not destroyed even if the power is turned off. The data is maintained for a longer period. ( 8 ) Repetitive mode – The COR 5500U can store repetitive signals up to 100 MHz. PRECAUTIONS ( 1 ) Receiving Inspections – The oscilloscope has been subjected to electrical and mechanical tests to guarantee the satisfactory quality and performance. ( 2 ) General precautions - This section is about electrical and mechanical precautions for safe and correct use of the oscilloscope. Read this section before start using it: • Checking the AC line voltage and frequency Operate the oscilloscope on as rated AC input voltage of 100 through 240 V, frequency 50 through 400 Hz, although it is permissible to operate the oscilloscope on an AC line voltage of 90 -250 V, frequency 45-440 Hz. • Checking the type and ratings of fuse Before connecting the power cable to the AC inlet of the oscilloscope, check the type and rating of the power fuse. The fuse holder of the oscilloscope is structured integrally with the AC inlet. The fuse holder cap can be detached by using a screwdriver or a pointed tool as showing bellow. Two fuses (one of which is for replacement spare) are put in the cap. Fig 2 Take out the fuse and check that is a slow-blow fuse of 250 V AC, 2 A. Return the fuse and cap to the original positions by following the take out procedure in the reverse order. Fully insert the cap until it clicks. When you replace the fuse with a new one, make sure to use a correct one. The spare fuse is put in the fuse hold cap. When the fuse has also used up, you may use a new one available on the market, but be sure that it is the correct type and rating. Warnings: Never use a wrong or incorrect fuse. Never short-circuit the fuse holder terminals instead of the fuse. These operations might result in serious damage and hazards. ( 3 ) Checking the power cable - Be sure that the power cable is supplied as an accessory of the oscilloscope. The power cable has a 3-color wire and a 3-pin receptacle; one of the three pins being for safety grounding. ( 4 ) Environments Avoid using oscilloscope in environments as mentioned below: a) High temperature – Do not expose the oscilloscope to direct sunlight or other source of heat. The ambient temperature range for the guaranteed performance is 10 to 40ºC or 50 to 104ºF. b) High humidity – Do not use the oscilloscope in high humidity. The humidity range for guaranteed performance is up to 75% RH. c) Electronic magnetic field - Do not use the oscilloscope in strong electric or magnetic field, lest the displayed images should be distorted, or otherwise adversely affected. d) Unstable position - Do not use the oscilloscope on a swaying bench or other unstable positon. e) Flammable atmosphere - Do not use the oscilloscope in flammable or explosive atmosphere, to prevent fire and explosion hazards. f) Blocked ventilations holes – Do not block the rear, side and button panels. Provide an ample space behind the rear panel, where the air-cooling fan is installed on. ( 5 ) Preserving the CRT (9) PUSH BUTTON SWITCH: if inserted serially to a circuit, you can have ON-OFF operation. (10) POWER SWITCH: turns ON and OFF AC 100V or 220 V input. (11) DC OVERLOAD ALARM: gives a warning sign in case of overloading troubles. (12) 60 Hz OUTPUT: outputs AC 4.5 V(RMS) with 60Hz. This signal can be applied to clock signal or time base. (13) BUZZER INPUT: operates on 2-5V. The input current is less than 1 mA (as small as CMOS output). ()15DC OUTPUT: provides + 5V/ - 5V DC power, with is used for digital circuits. ()16CURRENT METER: measures load current of 5V out put. It is connected serially with output. ()17COMMON MODE SWITCH (CM SELECTOR): selects input polarity to LED indicator. If put to “ANODE”, LED will be ON with input “0”. Contrarily, if put to “CATHODE”, LED will be ON with input “1”. 3. Logic Lab Unit operating procedures • WARNINGS • Make sure that AC input voltage is 110V or 220 V and select corresponding voltage input selector at rear panel; • Keep this unit away from heat and dusty place; • When you connect the circuit on bread board, use jump wire whose diameter is less than 6 mm; • Make sure that pin 1 (index notch) identification of all IC is correctly directed as you designed; • Check if Vcc/Vdd of every IC is connected to proper power supply. • PROCEDURES •..1 Turn the power switch OFF; 10 •..2 Connect +5V DC and GND with bus strip on bread board. Be aware that pin 14 or 16 of IC is Vcc/ Vdd and pin 7 or 8 is GND usually; •..3 Place all the ICs and other parts so that connections between them may be done easily. While doing this, take into consideration about LED indicators and logic switch too; •..4 Connect them using jump wire. It is recommended to use wires with different colors according to their usage for future checking. Example: +5V……..red Output…………white Others……green Input …… yellow GND…………..black •..5 Check the circuit connections again. If everyone is correct, turn the power switch ON. Keep and eye on current meter. If excess current is indicated, turn the power switch OFF immediately and find out if there is any shorted circuit between +5V and GND; •..6 After everything is proved right, do your experiment using those switches and indicators properly. MINILAB TECHNICAL TERMS BUZZER INPUT - entrada de sonorizador, buzina BREAD BOARD- placa de alimentação BUS STRIP- barramento, barra ônibus CLOCK SIGNAL - sinal de relógio COMMON MODE SWITCH- comutador de modo comum CONTROL PANEL - painel de controle CURRENT METER- amperímetro ou medidor de corrente FRONT/ REAR BOARD- placa frontal/ posterior FRONT/ REAL PANEL- painel frontal/ posterior HEXADECIMAL DISPLAY- mostrador em hexadecimal HIGH LEVEL- nível alto/ elevado (“1”) INDEX NOTCH- entalhe marcador JUMP WIRE- fio “jumper”, ponte, ligação direta LED INDICATOR- indicador luminoso LOGICAL LEVEL- nível lógico LOW LEVEL- nível baixo (“0”) NUMBER DISPLAY- mostrador de números PANEL CONTROLS- controles do painel POWER SUPPLY- suprimento de energia elétrica, fonte de alimentação POWER SWITCH - chave, interruptor, alavanca ou tecla para alimentação PROTO BOARD - placa para montagem de protótipos PUSH BUTTOM SWITCH - tecla de pressão comutadora SHORTED CIRCUIT- curto circuitado, “em curto” SWITCH OFF - desligado, desarmado SWITCH ON - ligado, armado TIME BASE - base de tempo 11 VOLTAGE METER - voltímetro WIRE COLOR - cor de fio ou condutor ABREVIATIONS/ MONOGRAMS AC (LTERNATE CURRENT) - Corrente alternada BCD (BINARY CODED DECIMAL) - decimal codificado em binário CMOS (COMPLEMENTARY METAL OXIDE SEMICONDUCTOR) - semicondutor metálico DC (DIRECT CURRENT) - corrente contínua GND (GROUND) - aterramento, terra IC (INTEGRATED CIRCUIT) - circuito integrado LED (LIGHT EMITTING DIODE) - diodo emissor de luz RMS (ROOT MENA SQUARE) - valor médio quadrático ou eficaz SW (SWITCH) - chave, interruptor, interruptor, alavanca VR (VARIABLE RESISTOR) - resistor variável MINILAB RESEARCH According Emit Output Useful According All Enable Own Useless All Alternate Experiment Panel Very Alternate Alternative Feature Pin View Alternative Anode Find Procedure Voltage Anode Any First Proper Wave Any Apply Five Provide Warning Apply As small as Following Push Which As small as As well as Front Pulse White As well as At your own Furnish Put Whose At your own Away Ground Range Wide Away Be off Heith Rear Width Be off Be on High Red Wire Be on Because In order to Right yellow Because Between Index Same Consist Between Black Input Second Current Black Board Integrated Serially Design Board Bread board Jump wire Several Devise Bread board Buzzer Keep an eye Shord Diode Buzzer Cathode Knob Shorted Direct Cathode Multitester – Instruction Manual 12 •.-A Connect the “P” terminal of the tester to the emitter of the transistor with the hFE test lead; •.-B Plug the hFE connector into “N” terminal and connect its red clip to the collector and the black one to the base of the transistor; • For PNP transistor: •.-A connect the “N” terminal of the tester to the emitter of the transistor; •.-B Plug the hFE connector into the “P” terminal and connect the clips in the same way as for NPN transistor connection; (4) Read the hFE scale. The value of the reading is Ic/ Ib, which is the DC amplification degree of the transistor tested. DIODE TEST (1) Set the range selector at selected range position – X1K for 0 – 150 µ A, for 15mA, X1 for 0 – 150 mA test; (2) Connect the diode to the tester: • For IF (forward current) test connect the “N” terminal of the tester to the positive polarity of the diode and the “P” terminal to the negative polarity of the diode. For IR ( reverse current) test, reverse the connection; (3) Read IF or IR one the LI scale provided; (4) Read the linear (forward) voltage of the diode on the LV scale while testing IF or IR. Electronic Circuits Introduction This unit introduces you to electronic circuits and explains the meaning of current, voltage and resistance. You will find out about Ohm’s equations and about some of the components used in building electronic circuits. Shining a light 15 Have you ever taken an torch to pieces to find out how does it work? Look at Fig. 1 below, which shows the arrangement of parts inside a torch. Why did the designer of the torch choose this particular combination of materials? The metal parts must conduct electric current if the torch is to function, but they must also be able to stand up to physical forces. The spring holding the cells in place should stay springy, while the parts of the switch must make good electrical contact and be undamaged by repeated use. Which materials used in making a torch are conductors and which are insulators? ( ) plastic ( ) copper ( ) tungsten (lamp filament) ( ) glass (outside of lamp) Drawing a circuit diagram A different way of describing the torch is by using a circuit diagram in which the parts of the torch are represented by symbols. In Fig. 2 there are two electric cells (“batteries”), a switch and a lamp (the torch bulb). The lines in the diagram represent the metal conductors which connect the system together. A circuit is a closed conducting path. In the torch, closing the switch completes the circuit and allows current to flow. Torches sometimes fail when the metal parts of the switch do not make proper contact, or when the lamp filament is “blown”. In either case, the circuit is incomplete. The diagrams show different arrangements of cells, switches and lamps. Fig. 3 Current An electric current is a flow of charged particles. Current is sometimes carried by positively charged particles, but inside a copper wire, current is carried by small negarively charged particles, called electrons. Metals, such as copper, contain free electrons, which drift in rang]don directions as shown in Fig. 4. Fig. 4 Voltage Each cell provide a push, called its potencial difference or voltage. This is represented by the symbol V, and is measured in volts, V. Sometimes, you will want to measure voltages in thousands of a volt, or milivolts, mV. Typically, each cell provides 1.5 V. If cells are joined together one after the other, they are said to be connected in series. Two 1.5 V cells connected in series provide 3V, while three cells provide 4.5 V. Fig. 5 Resistance If a thick copper wire is connected from the positive terminal of a battery directly to the negative terminal, you get a very large current for a very short time. In a torch, this 16 does not happen. Part of the torch circuit limits, or resists, the flow of current. Most of the circuit consists of thick metal conductors which allow current to flow easily. These parts, including the spring, switch plates and lamp connections, have a low resistance. The flow of current through the filament causes it to heat up and glow white hot. Lamp filaments are usually made of the metal tungsten because of its very high melting point. In hair, the filament would quickly oxidize. This is prevented by removing all the air inside the glass of the lamp and replacing it with a non-reactive gas. Ohm’s equations The relationship between current, voltage, and resistance was discovered by Georg Ohm, who published his results in 1827. Ohm made his won wires and was able to show that the size of an electric current depend upon their length and thickness. The current was reduced by increasing the length of the wire or by making it thinner. Current was increased if a shorter thicker wire was used. In addition, larger currents were observed when the voltage across the wire was increased. From experiments like these, Ohm found that, at constant temperature, the ratio of voltage to current was constant for any particular wire, that is: Where, R = resistance, V = voltage and I = current. Ohm’s Law states that, at constant temperature, the electric current flowing in a conducting material is directly proportional to the applied voltage, and inversely proportional to the resistance. Rearranging the formula gives two additional equations: and These simple equations are fundamental to electronics and, once you have learned to use them effectively, you will find that they are the key to a wide range of circuit problems. You are going to need these equations, so learn them now. Did you know…? Light bulbs The lamp filament was first invented in 1860 by a British physicist, Sir Joseph Swan. When electric current passes through a thin filament of conducting material, the filament heats up and, if the current is large enough, the filament becomes first red hot and then white hot, or incandescent. In air, this effect is short-lived because the filament burns up and breaks. Swan had the idea of enclosing the filament in a glass container, preventing oxidation by removing the air inside the container using a vacuum pump. These early experiments suggested that a useful light source was possible, but Swan did not have as sufficiently powerful vacuum pump. Years later, Swan tried again using a better vacuum pump. In 1878, he has successful in demonstrating a true incandescent light bulb. 17 resistor has a purely real conductance. When a voltage is applied, the electrical energy is converted into thermal energy. Since many of the resistor´s electrical characteristics are dependent on the temperature, the behavior of the resistance-temperature curve is significant for determining the range of possible applications. We speak of linear resistors or ohmic resistors, when their voltage/ current behavior is linear and obeys Ohm´s Law R= V/l (where R= resistance, V= voltage, l= current). As a rule the resistance is temperature dependent: RT = TT0 . (1 + ά . ∆T). ∆T is the temperature variation and ά is the temperature coefficient. INTRODUCTION General The region under consideration is Northeast Brazil between 1º and 18º south latitude and between 35º and 47º west longitude. This covers an area of almost 1.6 million km2 (see fig. 1). This region exhibits a pronounced time and space variability in the rainfall distribution, with a drastic dry inland region where the annual normal rainfall is below 500 millimeters (~ 20 inches). Serious social and economic problems result from the regional population requirements of over 20 million people and their dependence upon agriculture. It is noteworthy that the region is located in a latitudinal band where a regular distribution of rainfall should be expected. This region was first 20 settled in the early 16th century. It is felt that in previous centuries the rainfall was somewhat greater than it is now. Some natural or man induced climate changes may have taken place. It is difficult to forecast the wheather in this area due to the lack of detailed knowledge of the tropospheric wind structure and its influence on meteorological phenomena. Careful investigation of the relationship between wind, temperature, moisture and weather distribution, as well as the orographic influences, would provide a better understanding of the rainfall amounts and their variability. This should increase the reliability of weather forecasts required to carry out the many meteorologically sensitive human activities in this region. This is the purpose of this study. TESTS ON INDEPENDENT DATA Standard statistical tests of significance are not strictly applicable to meteorological prediction because the data are usually correlated in both space and time, and the weather regime of one period may be entirely different from that of another. These difficulties were compounded in the present study because the predictors were not chosen at random, and the regression equations were derived from observed heights but applied to numerical prognostic heights. Hence no tests of significance giving exact confidence intervals or probability levels were applied. Instead all prediction equations were tested on independent data samples. Unfortunately, however, these samples were rather limited in size because of paucity of data, particularly in the form of numerical prognoses, so that the results of the prediction experiments to be described here may not 21 be duplicated on future samples. These results should therefore be interpreted only as tentative and approximate indications, not as conclusive or quantitative findings. Assembly Languages Assembly language is a programming language that talks fairly directly to the computer. Unlike machine language, which is what the computer understands, assembly language is mnemonic, so that it can be understood and remembered more easily by a human being; in fact, assembly language is really just machine language in mnemonic form. Assembly languages are specific to a given CPU chip and are named after it (e.g., 8080 assembly language, 6809 assembly language etc.). They are harder to program than a high-level language, but they produce programs that are more efficient and run faster. VOCABULARY Fairly = quase Unlike = ao contrário de, diferente de Just = apenas, justamente CPU = Central Processing Unit = Unidade Central de Processamento Are named = recebem o nome After it = de acordo com ele (chip) Harder = mais trabalhosas Run faster = rodam mais rápido Inputting / Outputting Information Magnetic tape – it is one of the principal input/output recording media used with computers and is mainly used for storing intermediate results of computations and for compact storing of large amounts of data, in an ordered sequence. It is much cheaper to store information 22 VOCABULARY Deals with = trata de… Rather than = em vez de Echoing back = devolvendo Would come into play = entraria em ação Library’s holdings = arquivos da biblioteca Binary Numbers Binary numbers are well suited for use by computers, since many electrical devices have two distinct states: on and off. They are the numbers computers themselves understand. Composed entirely of zeros and ones, they express all values in powers of two. The advantage of the binary system is that you only need two symbols (0 and 1) to express any number, no matter how big it is. Since computers are basically just large groups of switches, and since these switches can only be either on or off, binary system fits right in; you just define 0 as off and 1 as on and then binary numbers tell the computer which switches to throw. The table below shows some numbers written in binary and decimal form. Note that writing numbers in binary requires more digits than writing numbers in decimal. Decimal Binary Decimal Binary 0 0 11 1011 1 1 12 1100 2 10 13 1101 3 11 14 1110 4 100 15 1111 5 101 16 10000 6 110 17 10001 7 111 18 10010 8 1000 19 10011 9 1001 20 10100 10 1010 VOCABULARY Well suited = well appropriate = bem adequados, aprorpiados In powers = em potências No matter = não importando Since = uma vez que Switches = chaves Either ... or = ou ... ou Fits = suits = é adequado, apropriado. 25 Different Kinds of Memory Read only memory (ROM) – In most computers it is useful to have some of the instructions or whole programs permanently stored inside the computer. There are particular kinds of chips which enable us to do this so that the memory is not lost even when the machine is switched off. These are called ROM chips. ROM stands for “read-only memory”. The word “non- volatile” is often used to describe this kind of memory – meaning that it is not destroyed when the power is switched off. Random-access memory (RAM) – The other kind of memory found inside computers is called RAM. Another name for it is “read/write memory”. RAM chips are the kind which lose their contents when the power is lost – so this kind of memory is sometimes also described as “volatile”. In the computer, RAM is the working memory. Back-up memory – The last kind of memory which concerns us is “back-up” memory. This is memory outside the main body of the computer in which programs can be kept for future use or in which data can be kept until the computer is ready to use it. It could be a cassette tape or a magnetic disk. VOCABULARY Chip = dispositivo que contém muitos transistores e outros componentes montados sobre uma peça de silício Enable us = capacita-nos Random Access memory = tipo de memória da qual a informação pode ser instantaneamente copiada, não importando onde ela esteja localizada; memória de acesso randômico ou aleatório Concern us = diz respeito a nós, concerne a nós Programming Languages Just as there are many human languages, so there are many computer languages. In the early days, people programmed using the computer’s binary code, or what we call “machine language”. When this became difficult, mnemonics were used to make life easier. This is called “assembly language” programming. Finnally, there are the “high-level” languages like BASIC, FORTRAN and ALGOL. These are much more similar to everyday language, and are translated directly or indirectly into the computer’s machine code using the computer’s firmware. BASIC is the language most often used to introduce programming. VOCABULARY In the early days = no princípio, no início Mnemonics = arte de desenvolver a memória mediante processos auxiliares como a associação; mnemônica To make easier = tornar mais fácil High-level = alto nível BASIC = Beginners All-puspose Symbolic Instruction Code FORTRAN = FORmula TRANslation ALGOL = ALGOrithmic Language 26 Firmware = “software” armazenado em ROM em vez de disco What Is an Algorithm? An algorithm is a sequence of instructions that tells how to solve a particular problem. Once the problem has been identified, the next step is to select the best method for solving it. If the problem is a familiar one, standardized algorithms may be available from program libraries. But if standard algorithms are not available or suitable, a new algorithm must be written and then added to the program library. An algorithm must be specified exactly, so there can be no doubt about what to do next, and it must have a finite number of steps. A computer program is an algorithm that is written in a language that a computer can understand, but the same algorithm could be wirtten in several different languages. VOCABULARY Once = uma vez Standardized = padronizados Added = acrescentado, incorporado There can be no doubt = não pode haver dúvida Steps = passos, etapas 27