5.6 (a) Flashcards
What does the CPU (microprocessor) do?
It performs all of the mathematical and logic functions by manipulating the data in the memory
What is ROM?
Read only memory
- contains the main programme telling the CPU what to do, when to do it and how to do it
What is RAM?
Random access memory
- temporary storage until the data is needed for processing
What is the purpose of the I/O (input/output device)?
It provides the interface between the CPU and the outside world
What are the types of buses?
Data bus
Address bus
Control bus
What is the purpose of the data bus?
It is used to carry the associated data associated with a memory or I/O transfer
What is the purpose of the Address bus?
It specifies the memory location or I/O port involved
What is the purpose of the control bus?
It is made up of various control lines generated by the CPU
What is hardware?
The parts and devices use to process the digital data
What is software?
The programmes and instructions for the CPU
What is RAM also referred to as?
Volatile memory
- unsaved data is lost at power off
What is ROM also referred to as?
Non-volatile memory
- data and programming functions stored in the ROM are not lost at power off
What is a PROM?
Programmable read only memory
What does EPROM stand for?
Erasable programmable read only memory
What does EAROM stand for?
Electrically alterable read only memory
What is the advantage of using EAROM than using EPROM?
Each individual element of the memory can be changed without erasing all of the data in the other elements
How does EPROM work?
It works by first erasing the existing programme (by using UV light) from the integrated circuit (IC) pack. It’s then reprogrammed with a series of 1’s and 0’s
When first manufactured, what is important to remember about ROM?
It is not usually changeable after manufacture due to a special masking technique adopted
What is a reference computer?
A computer that may be used as a source of information/data.
- reference signals from this computer may be self contained
- it only provides outputs
What is an IRS?
Inertial reference system (a type of reference computer)
- using laser gyro’s and accelerometer’s
What are examples of IRS computers?
- Autothrottle
- flight control computers
- pilots horizontal situation indicators
- FMC (flight management computer)
How are computers more often classified as?
Classified on their tasks rather than by analogue, digital or hybrid
What is an information computer?
A computer that collects, processes and displays data.
What are examples of information computers?
- maintenance computers
- EICAS (engine indication and crew alerting system)
What are Storage/Monitor computers?
Computers that retain information provided to them by other systems and computers.
- they generally do little signal processing
What is an example of Monitor/Storage computer?
An electronic engine control monitor(EECM)
What are controlling computers?
Computers with a primary task of controlling something
What is an example of a controlling computer?
The flap/slat electronic unit (FSEU)
- monitors and controls the flap/slat position
What is an interactive computer?
A computer that can perform several different tasks depending on operator inputs.
What is an example of an interactive computer?
The flight management computer (FMC)
- the flight crew can enter information via the CDU (control display unit)
What are the 3 main types of computers used on aircraft today?
Analogue
Digital
Hybrid
Many problems arose from improper handling of new technology LRU’s. What was the unserviceability rate of the new technology found in the same test conditions as the old ones?
It was three to four times higher
Why is a faulty integrated circuit hard to inspect by maintenance shop personnel?
The automatic testing equipment are often not able to discover the problem
