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• Airspeed indicator


  Instrument that measures the aircraft's speed in nautical miles per hour
• Attitude indicator


  Instrument that displays the aircraft's attitude relative to the earth's horizon
• Altimeter


  Instrument that shows the barometric altitude as measured in feet
• Heading indicator


  Instrument that indicates the direction in which the aircraft is flying
• Turn coordinator


  Instrument that displays the rate of turn in the roll axis and the amount of bank in the yaw axis
• Vertical speed indicator


  Instrument that provides information about the rate of ascent and descent in feet per minute
• Electronic attitude directional indicator


  In a glass cockpit, the artificial horizon with lateral bars superimposed, displaying computer-generated pitch and bank steering commands from the Flight Director computer
• Horizon situational indicator


  Digital instrument that is a combination of navigation commands from VOR or GPS receivers for en-route guidance and from the ILS for terminal guidance
• Engine indication crew alerting system


  System manufactured by Boeing aircraft that performs the monitoring of aircraft systems, with the upper displaying engine performance data and the lower is known as Multifunction Display
• Binary numbering system


  Numbering system used in computer architecture and digital electronics, with a base 2 and a series of 0s and 1s forming strings known as machine language
• DeMorgan's theorem


  Theorem that states that two separate terms NAND together are the same as the two terms inverted and OR
• Ex NOR


  Logic gate that produces a Logic 0 output whenever either one of the two inputs is at Logic 1 and the other is at Logic 0
• Boolean algebra


  Frequently used to describe logical operations in avionics systems and analyze digital circuits
• Exclusive-OR gate


  When either of the inputs is Logic 1, but not both, the output is Logic 1
• NAND gate


  Combination of a NOT gate and an AND gate
• OR gate

  To have an output of Logic 1, at least one input must be at Logic 1
• Inverter/NOT gate


  If the input is logic 1, the output is logic 0
• Buffer gate


  Type of gate that has the same output as the input and does not affect the logical state of a digital signal
• NOR gate

  Combination of an OR gate and an inverter
• Computers found on board aircraft are used to provide vehicle and utility control; flight management; navigation, communication, and verification; caution and warning; and other essential functions
• Main Memory


  Stores information for later erasure by the CPU
• Control Bus


  Provides control signals between the CPU, Main Memory, and the I/O system in a parallel bus
• Flash memory


  Faster than EEPROM, allows memory to be rewritten and reprogrammed into blocks of memory
• System software


  Designed to directly operate computer hardware
• Binary


  Computer process information using digital data that is coded in single decimal digits, known as 'bits'
• Data Transfer System (DTS)


  External secondary data storage device used for downloading navigation flight plans to the FMC and for downloading maintenance data
• Input and Output (I/O) system


  Converts the information to other forms to facilitate communication with other onboard computers and their operators through external unidirectional serial buses
• PROM


  Ordinary PROM cannot be changed once assembled
• Aircraft computer systems must be certified to be fail-safe, allowing hard or software errors cannot cause a catastrophic safe-of-flight incident
• ADC


  Converts a sequence of binary digits into 'impulses' that are then processed by a deconstruction filter to smooth out the step response into continuous curves
• Ethernet was first introduced in 1970 - 1980
• IEEE 1394 (Firewire)


  Originally developed by the IEEE for the consumer electronics industry as a parallel point-to-point interface
• Time-Division Multiplexing


  Enables different forms of information to be received through one communication system
• Digital signals have only two levels of voltage; high ON and low for OFF
• Microprocessor


  Retrieves and processes instructions and coordinates the flow of data throughout the computer
• Integer Arithmetic Logic Unit


  Designed to carry out operations typically addition, subtraction, multiplication, division, square root, and bit shifting
• Motorola MC68000


  Microprocessor used in the Boeing 777, running at clock speeds of 20 Mhz
• Address Latch Enable


  Function of a microprocessor that indicates which bytes on the address bus are valid to use
• CMOS (Complementary-Metal Oxide Semiconductor)


  Used for the voltage and ground for the microprocessor, 3.3 volts DC
• Medium Scale Integration


  Used for adders, counters, registers, comparators, encoders, decoders, multiplexers, de-multiplexers, etc.