Connecting Culture to Language
for visiting students from Denmark's Teknisk Gymnasium
Computer Science component

David Morgan
Santa Monica College



Binary numbers

Number systems

ASCII chart
Foreign "ASCII"
Foreign keyboard

CPU Registers

A CPU instruction

HTML reference

Big snowman
Little snowman

Slide presentations

Shelley textbook
Chapter 1 Intro
Ch 2


January 2015
Business Building Rm 250
Mon-Thu, Jan 26-29, Mon, Feb 2, and Wed, Feb 4

This Website (  will be used to communicate with you. It can be viewed from an internet-connected browser  anywhere. This summer class is not for credit. No books are required. There will be no assigned homework and no test.

Raspberry Pi releases a new version. (2/2)

Sample program in Alice language - here is a starter file. (1/29)

How many computer languages are there? (1/29)

yubikey device - comes from yubico. Google established a business relationship with yubico last fall for implementing 2-factor authentication using yubikeys. It uses a particular yubico product called Fido U2F security key. The FIDO ("fast identity online") alliance is an industry group promoting 2-factor authentication. (1/28)

Many operating systems - in an easy-to-try form. Here is a list of various self-contained bootable linux CDs. (1/28)

Virtual machines - a screenshot showing 2 different machine virtualizer products (libvirt, and VMWare).

Adding 3+2 (it's 5!)

Listen if interested to this 9-minute video about hardware underpinnings of information representation. (1/27)

First personal computer - Altair by Ed Roberts

(click photo to enlarge, note switches and lights on front panel)


European spacecraft landed on comet on November 12, 2013. Comet's relative size:


Space stikes back? news this morning. (1/26)

Telephone junction box - on my street corner. The house wires from me an my neighbors on the block all concentrate here. Then they run a couple miles to the "central office" building at Melrose and Crescent Heights. It services the surrounding area of about a 3-mile radius. Your house is similarly served by a junction box somewhere near you. Look for it. If you get DSL service to connect to the internet, it's speed will depend greatly on your distance from the central office.

example of the newer VRAD boxes ("video ready access device") containing fiber end-points for  delivery of TV, phone, internet to surrounding homes:


Obtaining the Alice programs that appear in the textbook - go here and on the resulting page:

please click "Data Files for Students (Windows)" whence you can download 2 files. They are self-extracting zip files. That is, they are executable files which, when executed, spit out the actual programs found in the book. On my system, by default they placed the programs in a folder called C:\Course Technology\3771-7. Therein I found folders for each chapter of the book. For example the "Alice and White Rabbit" program was among them under a "Chapter01" subfolder. Then if you wish you can run these programs so they come to life as you read about them. (1/26)

Obtaining, installing, using Alice (1/26)

CPU instructions - I use the example that a circuit designed to be able to take 2 numbers and either add, subtract, mulitply, or divide them could be instructed which operation to perform by giving it a number. How about:

 1 = add
 2 = subtract
 3 = multiply
 4 = divide

This is crazy oversimplified! but correctly analagous to how CPUs work. See the link entitled "A CPU instruction." It documents the instruction to the Intel 8086 CPU telling it to subtract. That instruction is a number. What number? Not 2. That's just my silly example. The actual number is shown in binary, as "0010110w" where w might be either 0 or 1, probably 1. So then, the actual number is 00101101. That's 45, same thing. The point is, the various operations do have instructions, which are numbers, and when you express them in the appropriate CPU register by setting its bits to that number, the CPU does the operation. (9/23)

CPU registers - are little parking places for numbers inside the CPU. See the link entitled "CPU Registers" at left. It shows 14 parking places/registers. Each one is 16 bits wide, for holding a binary number that has 16 digits (1s and 0s). The Intel 8086 model CPU shown powered the original IBM PC. It is the ancestor of the whole family of today's consumer CPUs from the Intel Corporation. (1/26)

A grand tour of the motherboard (1/26)

Binary and other ways of counting - please read the material at the links (below left) entitled "Binary numbers" and "Number systems" (1/26)

Binary clock - this clock is kind of interesting. (1/26)

First general-purpose digital computer Eniac, and its original quite specific purpose. (1/26)

Where it all began
 Boelter 3420 - listen to the BBC interview (first 8 minutes)
 UCLA professor Kleinrock (say "thank you") on starting the internet (1/26)

Low-end mini 1985 - RX405 by Rexon Business Machines, Culver City. (1/26)

A Remote Unix system is available for your use. I may ask you to submit homework to it, and fetch files from it that I have placed there. (1/26)

Using ssh (secure shell). ssh is an important tool you will use for interacting with remote computers. For that you will need an ssh client. There are a number of ssh client alternatives.


"What hath God wrought?"
May 24, 1844

"Mr. Watson come here, I want to see you."
March 10, 1876

October 29, 1969