1. History of Computers - Long, Long Ago
Abacus BC
beads on rods to count and calculate
still widely used in Asia!

2. History of Computers - 19th Century
Jacquard Loom
first stored program - metal cards
first computer manufacturing
still in use today!

3. 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

4. 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.

5. 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

6. 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.

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

8. UNIVAC
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

9. 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).

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

11. 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.

12. 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

13. The First Microprocessor – 1971
Intel 4004 Microprocessor
The 4004 had 2,250 transistors
four-bit chunks (four 1’s or 0’s)
108Khz
Called “Microchip”

14. 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.

15. 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.

16. 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.

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

18. 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.
Microprocessor’s instruction sets – the instruction that microprocessors can carry out – increased in size and sophistication.

19. 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

20. Generations of Electronic Computers

21. Computers Progress

22. Processor frequency trend
Frequency doubles each generation
Number of gates/clock reduce by 25%

23. 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!!!

24. What’s 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?

25. 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.

26. 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.

27. 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.

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

29. Power of a Microprocessors
Capability to process data.
Length of the microprocessor’s data word
Number of memory words that the microprocessor can address
Speed the microprocessor can execute an instruction

30. 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.

31. 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 microprocessor’s word length doubles, the processor becomes more powerful.

32. 4-bit microprocessors
4-bit microprocessor is popular for binary coded decimal (BCD) because of extremely low cost.
Example: toys, calculators, simple consumer products.

33. 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.

34. 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 microprocessor’s power.
4 bits can address 16 words in memory.
Common address ranges for 4-bit microprocessors are 4096 and 8192 memory words.

35. 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 microprocessor. If an addresses 32 kilo-words of memory, it memory will have _____ bits of data

36. 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.

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