English Man: "Iced Tea? Iced Tea? Good Lord Mildred. Did you ever hear of such a English Woman: "My word, no Henry. I think I should like to try some of that." The point trying to be made with these examples is that exposure theory states that nothing in life is obvious. What we do have are varying degrees of exposure. This means the next time somebody says: “It is painfully obvious to see the outcome of this situation,” do not get excited. Translate that statement into: “after being exposed to this situation for the last 20 years of my life, and having seen the same consequences for the same 20 years, it is now easy for me to conclude the outcome.” Well, this good sociology professor – I wish I remembered his name and could give him credit – impressed me with his obvious-bewilderment-exposure theory. Based on his theory I have created an equation: Bewilderment + Exposure = Obvious This equation states that bewilderment is where you start. With zero exposure it is not logical to immediately comprehend a new concept, let alone consider it to be obvious. However, let enough exposure come your way, and yes, you too will find something obvious that was confusing at the first introduction. This means that you need some special sympathy for your first instructor and your first book. I have had that theory work for, and against me. Students have come to me and said, “it made so much more sense to me when it was explained in college.” I have had the opposite claim with, “if only my first instructor had explained it as well as you did I would not have had so much trouble.” So just what is the point here? Something very weird happens with academic learning. Students, and I mean students of all possible ages, in all kinds of academic topics, expect understanding on the first go-around. Students open their books, and with some luck read a topic once. Perhaps a second, brief reading occurs immediately before an examination. And more than once, I have been told you told us that yesterday when I am repeating an important, probably confusing, point that requires repetition.
It should be that in a first year computer science class, students are not required to be able to convert numbers between bases. You will not be expected to figure out that 201 in base-10 converts to 11001001 in base-2 or vice-versa. However, if you are planning a career in technology, especially in the area of networking, then it is definitely an essential skill. We can also add some terminology here. A single bulb can be on or off and this single light represents a single digit in base-2, called a binary digit, which is abbreviated as bit. We also want to give a special name to the row of eight light bulbs (bits) that make up one character. This row shall be called a byte. Keep in mind that byte is not plural for bit. There is one problem with ASCII’s system of storing each character in a single byte. You only have access to 256 different combinations or characters. This may be fine in the United States, but it is very inadequate for the international community. Unicode is now becoming very popular and this code stores characters in 2 bytes. The result is 65,536 different possible characters. Java has adopted Unicode, as have many technical organizations. The smaller ASCII code is a subset of Unicode. Bits, Bytes and Codes Bit is a binary digit that is either 0 (off) or 1 (on). 1 Byte = 8 bits 1 Nibble = 4 bits (½ a byte) 1 Byte has 28 or 256 different numerical combinations. 2 has 216 or 65,536 different numerical combinations. ASCII uses one byte to store one character. Unicode uses two to store one character. Early computers did in fact use one vacuum tube for each bit. Very large machines contained thousands of vacuum tubes with thousands of switches that could change the status of the tubes. Miles of wires connected different groups of vacuum tubes to organize the instructions that the computer had to follow. Early computer scientists had to walk around giant computers and physically connect wires to different parts of the computer to create a set of computer instructions. The incredible advances in computer technology revolve around the size of the bit. In the forties, a bit was a single vacuum tube that burned out very rapidly. Soon large vacuum tubes were replaced by smaller, more reliable, vacuum tubes.
Assembly Language and the 1949 Assembly Language was introduced by the British with the EDSAC (Electronic Delay Storage Automatic Computer). This computer was inspired by the EDVAC and was the second stored-program computer. EDSAC had an assembler called Initial Orders which used single-letter mnemonic symbols to represent different series of bits. While still tedious, entering a program took less time and fewer errors were made. “Amazing Grace” Hopper was mentioned a couple sections ago as one of the first programmers of the Mark-I. She is also credited with making the term debugging popular after a couple colleagues pulled the first literal computer bug (a moth) out of the Mark-II. Her biggest accomplishments are in the area of computer languages. In the 1940s, Grace Hopper did not like the way we were programming computers. The issue was not that it was difficult. This issue was that it was tedious. She knew there had to be a better way. The whole reason computers were invented in the first place was to do the repetitive, tedious tasks that human being do not want to do. It should be possible to program a computer using English words that make sense, rather than using just 1s and 0s. Imagine the presidents of the United States and Russia want to have a meeting. The American President speaks English. The Russian President speaks Russian. Who else needs to be at this meeting? They need a translator. Grace Hopper understood this. If she wanted to program a computer with English words, she would need some type of translator to translate these words into the machine language of the computer. Grace Hopper wrote the first compiler (a type of translator) in 1952 for the language A-0. The language itself was not successful because people either did not understand or did not believe what a compiler could do. Even so, A-0 paved the way for several other computer languages that followed. Many of which were also created in part or in whole by Grace Hopper. Her immeasurable contributions to computer science have earned her the nickname “Amazing The Cray XE6 Hopper supercomputer and the USS Hopper Navy destroyer are also named after her.