History of Computers - Long, Long Ago

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History of Computers - Long, Long Ago
Abacus - 3000 BC

• beads on rods to count and calculate
• still widely used in Asia!

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History of Computers - 19th Century
Jacquard Loom - 1801

• first stored program - metal cards
• first computer manufacturing
• still in use today!

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Charles Babbage - 1792-1871
Analytical Engine

• Difference Engine c.1822
• huge calculator, never finished
• Analytical Engine 1833
• could store numbers
• calculating mill used punched metal cards for
  instructions
• powered by steam!
• accurate to six decimal places

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1948 and 1950s

• Transistor was invented in 1948 in the Bell Lab
  after WWII. But in the early 1950s, general
  purpose digital computers were using vacuum tubes
  to build basic logic gates and flip-flops.
• The vacuum tubes were bulky, not reliable and
  very hot.
• The programmer actually wired in the steps
  telling the computer what to do with data.
  Nothing was stored in the memory except data.

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First Computer Bug - 1945

• Relay switches part of computers
• Grace Hopper found a moth stuck in a relay
  responsible for a malfunction
• Called it debugging a computer

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Program Storage

• Later designs provide computer with program
  storage. The only way of knowing that some words
  are program steps instead of data is to check
  their location in memory.
• Designers jumped at the change to replace vacuum
  tubes with transistors in the late 1950s. These
  solid-state computers were already much smaller,
  cooler, and more reliable.

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First Transistor

• Uses Silicon
• developed in 1948
• won a Nobel prize
• on-off switch
• Second Generation Computers used Transistors,
  starting in 1956

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UNIVAC - 1951

• first fully electronic digital computer built in
  the U.S.
• Created at the University of Pennsylvania
• ENIAC weighed 30 tons
• contained 18,000 vacuum tubes
• Cost a paltry 487,000

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Early 1960s

• In the early 1960s, minicomputers were built for
  single kind of job.
• Dedicated minicomputers were found useful among
  scientists due to cheaper cost and had real
  value.
• A number of transistors were put on one silicon
  wafer. The transistors were connected together
  with small metal traces the building blocks of
  integrated circuit (IC).

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Integrated Circuits

• Third Generation Computers used Integrated
  Circuits (chips).
• Integrated Circuits are transistors, resistors,
  and capacitors integrated together into a single
  chip

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Mid 1960s

• SSI and MSI (small and medium-scale-integration)
  produce families of digital logic.
• A small drawer size 10,000 minicomputers in the
  1960s were as powerful as the room size computer
  of the late 1950s.

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Microprocessors

• In the early 1970, Digital computer and
  solid-state circuit allows to produce the
  microprocessors.Digital Computer is a set of
  digital circuits controlled by a program.
  Solid-state circuit is a very large scale
  integrated microcircuit - VLSI

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The First Microprocessor 1971
Intel 4004 Microprocessor

• The 4004 had 2,250 transistors
• four-bit chunks (four 1s or 0s)
• 108Khz
• Called Microchip

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1970s

• Large-scale-integration (LSI) become common.
• By the 1980s, VLSI gave us with over 100,000
  transistors.
• LSI were produced to perform universal function
  such as memory devices.
• 75 to 100 individual IC package for the
  electronics calculators were reduced to 5 to 6
  LSI circuit.

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Birth of Personal Computers - 1975
MITS Altair

• 256 byte memory (not Kilobytes or Megabytes)
• 2 MHz Intel 8080 chips
• Just a box with flashing lights
• cost 395 kit, 495 assembled.

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Mid 1970s

• After the calculator size was reduce, the next
  step was to reduce the architecture of the
  computer to a single IC resulting circuit was
  called the microprocessors.
• Early microprocessors processed digital data 4
  bits at a time slower and did not compare to
  minicomputers.

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Apple Computers

• Founded 1977
• Apple II released 1977
• widely used in schools
• Macintosh (left)
• released in 1984, Motorola 68000 Microchip
  processor
• first commercial computer with graphical user
  interface (GUI) and pointing device (mouse)

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1980s

• Complete 8-bit microprocessors were developed.
  They become popular as the basis of controllers
  for keyboards, VCRs, TV, microwaves. Then 16-bit
  and 32-bit were developed.
• Microprocessors instruction sets the
  instruction that microprocessors can carry out
  increased in size and sophistication.

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IBM PC - 1981

• IBM-Intel-Microsoft joint venture
• First wide-selling personal computer used in
  business
• 8088 Microchip - 29,000 transistors
• 4.77 Mhz processing speed
• 256 K RAM (Random Access Memory) standard
• One or two floppy disk drives

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Generations of Electronic Computers
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Computers Progress
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Processor frequency trend

• Frequency doubles each generation
• Number of gates/clock reduce by 25

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21st Century Computing

• Great increases in speed, storage, and memory
• Increased networking, speed in Internet
• Widespread use of CD-RW
• PDAs
• Cell Phone/PDA
• WIRELESS!!!

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Whats next for computers?

• Use your imagination to come up with what the
  next century holds for computers.
• What can we expect in two years?
• What can we expect in twenty years?

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What is a microprocessor?

• Unlike full-scale CPU, the microprocessor has
  digital logic made up of one LSI. Since LSI and
  VLSI are called microcircuits, it is easy to see
  why microprocessors has its name.
• It is a micro-processing unit in microcircuit
  form for data handling and computation under
  program control data processing unit.

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ALU

• Computation is performed by logic circuits that
  make up the Arithmetic Logic Circuit (ALU) Add,
  Subtract, AND, OR, Compare, Increment, and
  Decrement.
• ALU cannot itself move data from place to place.
• Like a blindfolded juggler ALU must wait for
  data to be placed in certain places.

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Control Logic

• In order to process data, the microprocessor must
  have control logic which tells the microprocessor
  how to decode and execute the program a set of
  instructions.
• It fetches them one at a time and decodes the
  instruction. Then the control logic carries out
  or execute the decoded instruction.
• It also controls how the microprocessor works
  with memory, input and output.

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Microprocessors and Microcomputer

• The microprocessor is never a complete, working
  product by itself.
• The microcomputer is a CPU based, personal
  computer (PC).

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Power of a Microprocessors

• Capability to process data.
• Length of the microprocessors data word
• Number of memory words that the microprocessor
  can address
• Speed the microprocessor can execute an
  instruction

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Length of Data Word

• Each microprocessor works on a data word of fixed
  length.
• Word lengths of 4 bits, 8 bits, 16 bits, and 32
  bits are most common.
• 8-bit word length are common that it has been
  given the name byte.
• Some 16-bit microprocessor have instruction s
  processed in two 8-bit bytes.

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Byte and Word

• 4000 bytes on an 8-bit microprocessor equals 4000
  words on a 4-bit microprocessor, 4000 bytes
  equal 8000 words.
• Each time the microprocessors word length
  doubles, the processor becomes more powerful.

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4-bit microprocessors

• 4-bit microprocessor is popular for binary coded
  decimal (BCD) because of extremely low cost.
• Example toys, calculators, simple consumer
  products.

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8-bit Microprocessors

• It is famous because
• The 8-bit word length is twice 4 bits,
• The 8-bits word length allows two BCD numbers for
  each CPU data word, and
• The 8-bit length can hold all the data needed for
  one character in the ASCII.

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Number of Memory Word

• Each word in memory is assigned a location number
  or address.
• The larger the number of memory addresses, the
  greater the microprocessors power.
• 4 bits can address 16 words in memory.
• Common address ranges for 4-bit microprocessors
  are 4096 and 8192 memory words.

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Memory Word

• 8-bit microprocessors have an address range of
  65,536 memory words in the 65,536 bytes memory
• For the same memory size, 16-bit have 32,768 word
  memory.
• Question A 16-bit word length is used by the
  80286 microprocessor. If an 80286 addresses 32
  kilo-words of memory, it memory will have _____
  bits of data

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Speed of Executes an Instruction

• Microprocessors have a oscillator circuit known
  as clock.
• Slow microprocessors runs on a few hundred
  kilohertz. It takes 10 to 20 microseconds to
  execute one instruction.

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Benchmark Programs

• Comparisons are more meaningful when they find
  out how long a given operation will take on the
  different processors.