Elements of Computer Architecture



Introductory lectures

A. It is fascinating and at the same time a bit frightening to see the speed in which a technology becomes obsolete when another technology succeeds to replace it. The transition is often brutal. A striking illustration is provided by the quick replacement of magnetic core memories by semiconductor memories after the introduction of the INTEL 1103 which was released in 1970 as the world's first commercial DRAM (Dynamically Random Access Memory). You can have a look at these two videos on the magnetic core technology which was prominent from the 1950s to the early 1970s:




This magnetic core technology is the origin of the terminology "core dump". More information on the first five microchips designed by Intel will be found here. A nice story of the starting years of the Intel company was released here on the occasion of the 15th anniversary of the company.

B. If you want to appreciate the size of a 25nm transistor, you are welcome to visit this cute little application here. If you want to enjoy your trip even more, remember that the size of a transistor in the Intel 4004 is 10 microns, thus 400 times larger.

C. Have a look at this paper if you want to know more about the Meltdown attack.



Lectures on semiconductors and transistors

A. If you are interested to know more about semiconductors and transistors, please have a look at the slides here and here.

B. Let me come back once again to the Visual 6502 project. If I have done well my job in these past two lectures, you should be able to understand the discussion about the different colored areas, as well as the description of transistors, power sources, inverters and NOR gates in the companion tutorial here. Note that the NOR gate and the apu_clk1 node mentioned in the tutorial are port of the Visual 2a03 project. As a matter of fact, it took me some time to find the NOR gate in the 2a03 circuit, and I thus thought convenient to deliver here a slightly larger picture of it:



Does that help to find the NOR gate in the Visual 2a03 circuit? Please take five or ten minutes of your time and give it a try! If you really cannot find the NOR gate in the end, you are welcome to have a look at the solution here.

C. Please have a look at this nice video if you want to see how the Z80 architecture was used in the Game Boy.

Lecture 5

A. As I mentioned during the class, one interesting example of emerging technology is provided by the microfluidic blood test. You are welcome to read that survey article and watch those magnificent videos




B. You may be interested to read here the paper by Danny Cohen, published on April 1st 1980, which introduced the terminology of little-endian and big-endian for the bit and byte order convention.


C. We will read that paper here on the economics of the iPhone. More generally, the history of Apple in the past 40 years is worth meditating, for its combination of technological, industrial and marketing elements. A fundamental and not so well-known aspect of this history is the creation and eventual failure of the NeXT company. Watch these videos and you will know more about NeXT and the influence of its technology (Mach-O, NeXTStep, OpenStep, etc.) on the Mac OS X operating system. Note that NeXTStep and OpenStep are the ancestors of what is called today Cocoa in Mac OS X.





It is also important to remember that most of these ideas (Graphical User Interfaces, mouse, SmallTalk, etc.) were originally developed for the Xerox Alto at Xerox PARC in the early 1970s, by distinguished computer scientists like Butler Lampson, Adele Goldberg, Alan Kay, Robert Taylor and Charles Thacker. The story tells that Steve Jobs visited Xerox PARC in 1979 when he was only 24 years old and had an esthetical shock, which convinced him to develop the Lisa and Macinstosh projects in this revolutionary line. The truth is of course much more interesting and not so simple as that, as you will get a glimpse from this short account here.





Lecture 6

If you like both poetry and coding, you will be interested by the International Obfuscated C Contest. More about it here or here. If you are interested in improving your programming skills, you may be also interested in following the activity of the ACCU association.


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