Quiz 1 IT 105 (chap 1) Flashcards
Who was Charles Babbage?
- An English mathematician, early 1800s
- Attempted to build a mechanical calculating machine
- He called it an “analytical engine”
What does the analytical machine resemble? What did the analytical machine do?
-It resembles the modern computer in many conceptual ways
- It envisioned the use of Jacquard’s punched cards for input data for the program
- Provided memory for internal storage, performed calculations as specified by the program using a CPU known as a “mill” and printed output
What happened in the late 1930’s and early 1940’s
-Several diff groups of researchers independently developed versions of the modern electronic computer
What is the Mark I ?
-This was built in 1937 by Howard H. Aiken
- Associates at Harvard with help/funding from IBM used thousands of mechanical relays
What are relays?
Binary switches controlled by electrical currents to perform Boolean logic
What is ABC?
- The first totally electronic dig computer was devised by John V. Atanasoff(physicist at Iowa State College in 1937)
- Machine was built in 1939 by him and a grad student clifford berry , using electronic vacuum tubes as the switching components
- It is a binary based machine
What did ABC consist of?
-An ALU with thirty units that could do addition and subtraction , a rotating drum memory that held thirty binary numbers of 50 digits each and punched card input
What are important aspects of the ENIAC?
- Generally considered to be the first all electronic digital computer
-Designed and built between 1943 and 1946 by John Mauchly and J. Presper Eckert at UPENN using the concepts that Mauchly saw in Atanasoff’s machine - Had limited storage capability with only 20 locations each capable of holding a 10-digit decimal number(an additional one hundred numbers could be stored in read only memory)
-Calculations were performed using decimal arithmetic
What were the most important improvements on the ENIAC?
- A memory that would hold both programs and data , the so called store program concept
- Binary processing data : this simplified the design of the computer and allowed the use of binary memory for both instructions/data
- also recognized natural relationship between the on/off nature of switches and calculation in the binary number system using boolean logic
-CPU includes control unit and ALU
What did the ENIAC contain?
-contained 18,000 vacuum tubes, occupied a floor space of more than 15,000 square ft, weighed more than 30 tons
- was recognized as an important achievement
-was operated until 1955 when it was dismantled(not destroyed )
What is the ENIAC project?
-in 1945 , John von Neumann who was a consultant on the ENIAC project, proposed a computer than included a big amount of improvements over the ENIAC design.
What are the important aspects modern computer architecture ?
- It is referred to also as von neumann architecture
- All early electronic computers relied on electronic vacuum tubes for their operation
- Today’s designs still reflect ABC, ENIAC, EDVAC, IAS
What are vacuum tubes?
-Bulky, made of glass, fragile, short lived, and required large amounts of power to operate
-require an internal electric heater to function , they fail very quickly and become “burned out”
- It is also known as an electron tube (device that controls electric current flow in a high vacuum between electrodes to which an electric potential diff has been applied)
- thermionic vacuum tubes came later , mini style, some w top cap connections for higher voltage
What is a transistor?
- A miniature semiconductor that regulates or controls current or voltage flow in addition amplifying/generating these electrical signals and acting as a switch/gate for them
-when working as an amplifier , a transistor transforms a small input current into a bigger output current
-As a switch, it can be in one of two distinct states (on or off) to control the flow of electronic signals through an electrical circuit or electronic device
Why are transistors important?
-They are used to create simple electronic switches
- Basic elements inn (ICs) which consist of a large number of transistors interconnected with circuitry and baked into a single silicon microchip
- In big numbers, They are used to create microprocessors where millions of them are embedded into a single iC
- Also drive computer mem chips and mem storage devices for MP3 players, smartphones, cameras, and electronic games
