The core is a physical entity, not just a metaphor. It has local habitations and names... -and those locations have names and addresses. At any given instant each address in that memory, each bit, will contain a one or a zero; it is a simple switch, and it will be on or off. Everything else that happens in a computer ... is built on that binary foundation.
Scott Rosenberg
Dreaming in Code, p. 65
Down to the Basics
The workings and terms of basic electronics often feels like a foreign language to me, even though I grew up in a home filled with equipment with which my father was always tinkering. For that reason I thought a primer of fundamental principles of electronics might be a helpful section for beginners and non-technical types like myself.
This section is always in construction! 
| Algorithm | In simple language, a step-by-step method for accomplishing a task (e.g. could be a recipe); for technical purposes, a well-ordered set of computable operations that, when carried through, produce a result in a finite amount of time. To use an algorithm to solve a problem or perform a task we will need to translate our needed procedure into steps that are correct, in order, efficient and computable. If we specify algorithm, we can execute a solution (e.g. cook a meal). |
| Binary | The word "binary" means composed of two parts or two pieces. The binary number system in a numeral system which represents values with only two symbols, 0 and 1. A binary number can use any sequence of bits (binary digits) which can in turn be represented by any mechanism which can operate in two mutually exclusive states (e.g. "off" and "on"). In a computer, the numeric values may be represented by two different voltages, or the presence of absence of current (as in switches and tubes); on a magnetic disk, polarities maybe used. |
| Bit | A bit is a BInary digiT, taking a value of either 0 or 1. It is the basic unit of information storage and communication in digital computing. |
| Boolean logic | A set of rules developed by mathematician George Boole (1815-1864) which now apply to binary propositions: statements which are either "true" or "false" and can be represented by the binary digits 0 and 1 which in turn can be represented by on or off states of electron flow. Boole's rules, even though they were not intended to do so, are ideal for today's computers. |
| Boolean operations | compare two or more input statements and output a true or false value. |
| Circuit Diagram | A simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified standard symbols, and the power and signal connections between the devices. Also known as an electrical diagram, wiring diagram, elementary diagram, or electronic schematic. Arrangement of the components interconnections on the diagram does not correspond to their physical locations in the finished device. Unlike a block diagram or layout diagram, a circuit diagram shows the actual wire connections being used. The diagram does not show the physical arrangement of components. |
| Computer Science | Computer science is the study of algorithms, including: – Their formal and mathematical properties – Their hardware realizations – Their linguistic realizations – Their applications |
| Wonder what your age, PIN or cell number looks like in binary? Enjoy a fun distraction with a javascript Decimal to Binary Converter | |
| Diode |  The simplest of all tubes, a tube in which electrons flow only from the negatively-charged cathode to the positively-charged plate or anode. The diode conducts current only in one direction. If the voltage of the anode is less positive than that of the cathode, no current will flow. Therefore, if an alternating voltage (alternating current or AC) is placed on the anode, electron current will flow only when the charge is more positive than that of the cathode. -This is called rectification, the first control action of a tube--changing an alternating current into a direct current. |
| Electronics | The science of controlling the flow of electrons in such a manner as to produce the desired result. The manner of doing this include circuitry using vacuum tubes or semiconducts. |
| Electrons | An atom is the smallest particle of matter which comprises one of the more than 100 known chemical elements. Atoms are made up of smaller particles, the most important three of which are the proton, the neutron and the electron. Electrons spin around the center, or nucleus, of atoms. The nucleus is made up of neutrons and protons. Electrons contain a negative charge, protons a positive charge. Neutrons are neutral -- they have neither a positive nor a negative charge. When a conducting path is provided, the electrons will move from an area of excess of electrons to one having a deficiency of electrons. Electronics is fundamentally the study of the behavior and uses of electrons and their flow as current from a source along a path. |
| Flip-flop | A single flip-flop can be used to store one bit, or binary digit, of data. The data contained in several flip-flops may represent the state of a sequencer, the value of a counter, an ASCII character in a computer's memory or any other piece of informaiton. Another use is to build finite state machines from electronic logic. The flip-flops remember the machine's previous sttate, and digital logic uses that state to calculate the next state. (wikipedia) |
| Logic Gates | The basis of digital circuits, gates are switches and produce an output signal representing either 1 or 0 according to a particular logical operation. Logic gates turn input into output according to Boolean logic. The physical representaiton of these gates is the hardware of AND gates, OR gates, and XOR gates and inverters, where a voltage or current performs the logical operation. Each logic gate requires power so that it can source and sink currents to achieve the correct output voltage. In logic circuit diagrams the power is not shown, but in a full electronic schematic, power connections are required. They are made of diodes or transistors, but can also be constructed using electromagnetic relays, fluidics, optics, or even mechanical elements. For our purpose, in studying the bombe, we see gates that are either mechanical or tubes. |
| Machine Code | Computer language based on binary digits. |
| Schematics | Drawings utilizing a standardized system of symbols which convey the necessary information about the circuitry, electrical components and measurements of a piece of electronic equipment in a simple manner. |
| Truth tables | Truth tables are simple charts where the logic of Boolean operations are represented by the numerals 1 and 0. True and false are indicated as inputs of 1 and 0; the output is the logical conclusion of true or false, current or no current.he first column of Figure 1 below tabulates the values of the four possible valuation; such a tabulation is traditionally called a truth table. For convenience, I've moved truth tables diagrams to a separate page |
Sources
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Latest update August 2, 2009