1. CISC101 Reminders Course Web Site:
Winter 2019 CISC101
4/12/2019
CISC101 Reminders
Course Web Site:
Labs start next week. Meet your TA! Get help with:
Exercise 1.
Python installation issues.
Lecture material.
Assignment expectations….
Winter 2019
CISC101 - Prof. McLeod
Prof. Alan McLeod

2. Exercise 1
This is set of exercises that can be carried out at the Python prompt.
You don’t need to do these now, but you can start on your own or wait until you are in the lab next week.
If you want to start these on your own, you will need your own Python installation. Or go to JEFF155 or JEFF157 any other time.
Look for the installation instructions on the Resources page in the course web site.
Winter 2019
CISC101 - Prof. McLeod

3. Today Take some of the “MAGIC” out of how computers work:
An overview of computer architecture.
How did the technology get to where it is today?
ENIAC
von Neumann Architecture
The Transistor
Integrated Circuits
Winter 2019
CISC101 - Prof. McLeod

4. Computer History Museum
A very well laid out and informative site covering the history of computing:
Winter 2019
CISC101 - Prof. McLeod

5. How Stuff Works Video See:
This is for a desktop, but a laptop has more compact parts that do the same thing, plus a battery.
What moving parts does a laptop have? What if you have a SDD – what moving parts are left?
Winter 2019
CISC101 - Prof. McLeod

6. Computer Architecture (PC)
Winter 2019
CISC101 - Prof. McLeod

7. CPU “Central Processing Unit” The heart of the computer.
Consists of millions of transistors on a single chip.
Next two slides show the physical layout of an older single core Pentium chip and then an i7 chip.
Winter 2019
CISC101 - Prof. McLeod

8. Winter 2019
CISC101 - Prof. McLeod

9. Winter 2019
CISC101 - Prof. McLeod

10. CPU - Cont. The latest: Six Core – six processors on one chip!
As hardware, they are characterized by their clock speed, which controls the number of operations per second that they can carry out.
The first PC contained an 8080 chip, introduced in 1979 that had a clock speed of 2 MHz or (2,000,000 cycles per second).
Now an Intel quad core i7 CPU chip can run 8 simultaneous threads on 4 cores at 4.2 GHz (4,200,000,000 cycles per second!)
Winter 2019
CISC101 - Prof. McLeod

11. Dual Core Processor
Winter 2019
CISC101 - Prof. McLeod

12. Quad core:
Winter 2019
CISC101 - Prof. McLeod

13. AMD six core:
Winter 2019
CISC101 - Prof. McLeod

14. Intel six core:
Winter 2019
CISC101 - Prof. McLeod

15. CPU - Cont. Responsible for:
Locating and carrying out program instructions from RAM.
Carrying out arithmetic operations on data stored temporarily in a few “registers”.
Moving data between RAM and other storage devices.
Sending data to I/O devices.
A CPU can only carry out machine language instructions.
The pins attached to a CPU are either “on” or “off”.
All high level program instructions must be reduced to binary machine code before the CPU can do anything with them.
Winter 2019
CISC101 - Prof. McLeod

16. RAM and ROM “Random Access Memory”
Volatile memory - when the power goes off, bye-bye go the bits!
Ultimately, numbers are stored in binary format (1 or 0) - more on this topic later!
RAM holds data and program instructions.
Winter 2019
CISC101 - Prof. McLeod

17. RAM and ROM, Cont. “Read Only Memory” Not volatile.
Contains code and (BIOS) data used to start (“boot”) the computer.
“BIOS” stands for “Basic Input Output System”.
Winter 2019
CISC101 - Prof. McLeod

18. Other Components Disk storage:
Data stored on magnetic or optical media.
Not volatile! (Hopefully!)
Disk read/write operations are much slower than operations carried out in RAM by the CPU.
Program code is first loaded from the disk to RAM and then executed.
Modern (but still rather pricey!) solid state drives (“SDD”) just have banks of non-volatile RAM:
Winter 2019
CISC101 - Prof. McLeod

19. Other Components Data ports Serial (RS232), USB, HDMI, video, etc.
Providing input/output for the user via the keyboard, mouse, monitor, sound card, microphone, printer, scanner, joystick, webcam (etc. - you get the idea!)
Modem, Network card and/or Wireless Adapter
Provide a means of connecting to other computers.
Winter 2019
CISC101 - Prof. McLeod

20. 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 2019
CISC101 - Prof. McLeod

21. Winter 2019
CISC101 - Prof. McLeod

22. ENIAC, Cont. See the video at:
Or:
Winter 2018
CISC101 - Prof. McLeod

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

24. 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

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

26. 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

27. 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

28. “von Neumann Cycle” Fetch
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