CS111 Basic Terms
Terms
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- Hardware
- any physical component involved with the computer's operation
- Software
- the programs that are executed on a computer
- Operating System
- a very large and complex program that allows users of the computer to execute commands or application software on the computer
- CPU (Central Processing Unit)
- where the computer executes its intructions
- ALU (Arithmetic and Logic Unit)
- operations like addition and multiplication are done here along with comparisons like >, <, and equality
- Peripheral Device
- externally connected to the computer, it can perform the desired I/O operations from the computer. (printer, external zip drive, etc.)
- Primary Memory
- directly accessible by the CPU and ALU, it is for short term storage, and it is where your programs will reside while executing
- I/O (Input/Output)
- information that goes into the software (and comes out of it)
- RAM
- primary memory is made up of random access memory
- Bit (Binary Digit)
- this is either a 0 or 1 (high or low voltage). All information in the computer is stored as some number of bits. (Each character is a byte)
- Byte
- an 8 bit quantity. (Everything on the computer is interperated in base 2)
- K
- 1024(2 to the 10th power). 128K is really 128 x 1024 bytes
- M
- 1024 * 1024(2 to the 20th power). 1 megabyte is roughly one million bytes.
- G
- 2 to the 30th power. 1 Gigabyte is roughly one billion bytes.
- Files
- the named entity on the computer to hold all relevant information on one topic. This is stored on a secondary memory device. (Think of a file as a notebook in a bookcase!) We will be using floppies, zip disks, or your own personal, shared (but accessible only by you), MIKENET server disk area.)
- Secondary Memory
- for long term storage. Zip disks, floppy disks, CDs, flash drives, etc., can hold the desired information for retrieval at a later time
- Machine language
- the strings of 0's and 1's that the computer can understand which represent the instructions it can execute
- Assembly language
- a low level language that is understandable by humans; it has a direct 1-1 correspondence with the machine language instruction
- High Level Language (HLL)
- is removed from what the machine's instructions are and is more English-like. HLLs use statements instead of instructions, but a statement will be changed into machine language instructions. Usually, one statement will translate into anywhere from 4 to 50 instructions.
- Compiler
- this is another very complex program that will translate your program that is written in a HLL, into a machine language that the computer can understand, or the interpreted bytecode that will run on any computer that has a Java Virtual Machine that understands and executes bytecode
- Basic (Beginner's All-purpose Symbolic Instruction Code)
- an early HLL to aid in the learning of the art and science of programming. (MS Visual Basic); designed at Dartmouth
- C, C++
- created at Bell Laboratories (now Lucent Technologies)
- Syntax
- a rigid set of rules specifying which entities are valid or invalid
- Semantics
- what is the meaning of something, in our case a HLL statement, i.e., what actions does the computer do when it executes a statement