1. CISC101 Reminders Your group name in onQ is your grader’s name.
Winter 2018 CISC101
11/12/2018
CISC101 Reminders
Your group name in onQ is your grader’s name.
Please fill out the office hour quiz in onQ.
Labs start this week. Meet your TA! Get help with:
Exercise 1.
Python installation issues.
Lecture material.
Assignment expectations….
Winter 2018
CISC101 - Prof. McLeod
Prof. Alan McLeod

2. Today Evolution of Computer Technology: Start Digital Systems Logic.
ENIAC, Cont.
von Neumann Architecture.
The Transistor.
Integrated Circuits.
Start Digital Systems Logic.
Winter 2018
CISC101 - Prof. McLeod

3. First Electronic Computer: ENIAC
(From Wikipedia:)
“Electronic Numerical Integrator And Computer”
First electronic computer, built in the late 1940’s to calculate artillery firing tables.
ENIAC contained 17,468 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million hand-soldered joints. It weighed 30 tons, took up 680 square feet (63 m²), and consumed 150 kW of power.
Winter 2018
CISC101 - Prof. McLeod

4. Winter 2018
CISC101 - Prof. McLeod

5. ENIAC, Cont. See the video at:
Or:
(We watched the second video last week in class.)
Winter 2018
CISC101 - Prof. McLeod

6. ENIAC, Cont.
Winter 2018
CISC101 - Prof. McLeod

7. ENIAC, Cont.
Six women (inducted into the Women in Technology International Hall of Fame) took several weeks to manually enter a single program into the machine:
Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman
Winter 2018
CISC101 - Prof. McLeod

8. Operating the “Differential Analyzer” (an analog mechanical calculator) in the basement of the Moore School ( ):
Winter 2018
CISC101 - Prof. McLeod

9. ENIAC, Cont. In 1942, their annual salary was $1,620
The job title of all of the women was “Computer”!
Winter 2018
CISC101 - Prof. McLeod

10. von Neumann Architecture
Conceived in 1944/5
The structure we have been referring to is still used in modern computers:
Separate units for input and output.
Data is stored in a separate memory location.
The “ALU” carries out instructions on data items moved into the ALU.
The “Control Unit” acts as a stage manager.
Winter 2018
CISC101 - Prof. McLeod

11. “von Neumann Cycle” Fetch Decode Fetch operands Execute
The address of the next instruction is read from the instruction counter. The next instruction is read from this memory address to instruction register.
Decode
The instruction is translated to a format that is usable for the execution unit by the decoder.
Fetch operands
Depending to the actual instruction operands from a memory location have to be fetched to be accessible for the execution unit.
Execute
The arithmetical logical unit performs the operations and writes the results to registers or memory according to the instruction.
Update instruction counter
The instruction counter is incremented for the next cycle. Now the first step can start again.
Winter 2018
CISC101 - Prof. McLeod

12. Aside – The First Computer Bug
In 1947 Grace Murray Hopper was a technologist on a Mark II Aiken Relay Calculator at Harvard University.
She logged the following:
Winter 2018
CISC101 - Prof. McLeod

13. Winter 2018
CISC101 - Prof. McLeod

14. Admiral Grace Murray Hopper
The word went out that she had “debugged” the machine.
Grace Murray Hopper became known as the “Mother of Cobol” and is one of the most important people in the history of computers.
Awarded (posthumously) the Presidential Medal of Freedom in 2016.
Winter 2018
CISC101 - Prof. McLeod

15. After the ENIAC Only this one ENIAC was ever built.
It was followed by the “EDVAC” in 1950.
The first commercial computer was the UNIVAC I, which was delivered to the Bureau of the Census in the U.S. in 1951.
Walter Cronkite at right…
Winter 2018
CISC101 - Prof. McLeod

16. Before Transistors…
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CISC101 - Prof. McLeod

17. Vacuum Tubes, Cont.
A bias voltage on the grid allows current to flow between the emitter (cathode) and the collector (anode).
(Can also be used as amplifiers.)
Large, lots of heat, lots of energy required…
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CISC101 - Prof. McLeod

18. Transistors
First demonstrated in 1947, at Bell Labs by William Shockley:
Winter 2018
CISC101 - Prof. McLeod

19. Transistors, Cont. Individual: Integrated Circuits (started: 1958)
Winter 2018
CISC101 - Prof. McLeod

20. Integrated Circuits, Cont.
Electron microscopy:
Winter 2018
CISC101 - Prof. McLeod

21. Moore’s “Law”
“The number of transistors in a processor will double every 24 months.”
Winter 2018
CISC101 - Prof. McLeod

22. Moore’s “Law”, Cont.
First documented by Intel co-founder Gordon E. Moore in 1965.
Is there a limit to Moore’s Law?
Limited by atom size?
Limited by our ability to get the heat out?
Limited by manufacturing capability?
Are there alternatives to Si based transistors?
Winter 2018
CISC101 - Prof. McLeod

23. Integrated Circuit Fabrication
See video at:
(Lots of others…)
Winter 2018
CISC101 - Prof. McLeod

24. How to Make an IC Try this at home! (Just kidding...) Basic steps:
Create and refine huge single crystal of Silicon (Si).
Cut wafers.
Apply photo-resist layer.
Expose pattern on photo-resist using UV light.
Remove exposed photo-resist, etch out exposed Si.
Dope exposed Si using ion implantation.
Remove all photo resist.
Add insulating layer with holes.
Electroplate with copper.
Build circuit above transistors with more copper.
Test, slice and package up.
Winter 2018
CISC101 - Prof. McLeod

25. Digital Systems Logic - Transistors
Transistors can be used to provide digital logic.
They work just like the following circuit:
Each wire in a computer has a signal that is either on or off for the duration of a single clock tick (a very short time!).
Winter 2018
CISC101 - Prof. McLeod

26. Transistors (Shamelessly borrowed from the Intel web site:)
Of course, on a CPU, these are all made on a base of single crystal Silicon, and layers are added and etched using photo-resist technology.
Doping determines whether it is “n” or “p” type Si.
Winter 2018
CISC101 - Prof. McLeod

27. Transistors - Cont. 2) Add voltage to gate: 1) No signal:
3) If drain is connected:
4) No signal on gate:
Winter 2018
CISC101 - Prof. McLeod

28. Transistors - Cont.
Source, Gate and Drain are also called “Collector”, “Base” and “Emitter”:
A 5V signal applied to the gate or “base” is enough to cause current to flow. Zero volts turns the signal off.
Combinations of transistors can be used to perform boolean logical functions, called “gates”:
Winter 2018
CISC101 - Prof. McLeod

29. “AND” Gate Two transistors forming an “AND” gate:
Both Input-1 and Input-2 have to be “1” (ie. 5 volts) for the Output to be “on”.
How an “AND” gate is drawn in a logic diagram:
Logic or “Truth” table:
Winter 2018
CISC101 - Prof. McLeod

30. “OR” Gate Either Input-1 or Input-2 can cause Output to be “On”.
An “OR” gate in a logic diagram.
Winter 2018
CISC101 - Prof. McLeod

31. “NOT” Gate The “NOT” gate just reverses the Input: Winter 2018
CISC101 - Prof. McLeod