This is a guess, but look at the link and you may decide to leave it alone.

My guess from the USA.

See ref.

Sometimes plug compatible mainframe.

Here's an interesting excerpt from the American Antitrust Institute:

http://www.antitrustinstitute.org/recent2/238.cfm

The European Commission's investigation of IBM during the early 1980s also emphasized bundling and non-disclosure of interface information. Beginning in the late 1960s, IBM experienced increasing competition from "plug-compatible" manufacturers (PCMs).



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Note added at 24 mins (2003-12-16 18:49:53 GMT)
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To understand the issue, Amdahl was to I-M like AMD is to Intel today. They made different processors known for their speed and performance, but users cpuld plug I-M\'s peripheral devices right into Amdahl\'s computers and they would not know the difference. Is it not ironic that AMD and Amdahl even sound similar?

INFO Online - INFOfaq - A -
... Adaptive Differential Pulse Code Modulation, técnica de modulação de código de pulso para a conversão dos sinais sonoros analógicos em formato digital. ...
info.abril.com.br/aberto/infofaq/faq_a_1.shl

PCM - Glossary - CNET.com
PCM pulse code modulation Sound is analog, and computers are digital.
So for a computer (and that includes CD and DAT players) to ...
www.cnet.com/Resources/Info/Glossary/Terms/pcm.html

pulse code modulation

PCM (pulse code modulation) is a digital scheme for transmitting analog data. The signals in PCM are binary; that is, there are only two possible states, represented by logic 1 (high) and logic 0 (low). This is true no matter how complex the analog waveform happens to be. Using PCM, it is possible to digitize all forms of analog data, including full-motion video, voices, music, telemetry, and virtual reality (VR).
http://searchnetworking.techtarget.com/gDefinition/0,294236,...

Glossary of Terms
9Z Specific Glossary: This incredibly powerful radio has a cluster of features all its own.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

3D
Term describing a type of flight pattern, which is characterized by the performance of very specialized aerobatic manuevers below the model's normal stall speed. Examples include torque rolls, 'walk in the park', harriers, hangers, etc.

For helis: combining two or more maneuvers into one maneuver. Examples: rolling circle, inverted backwards loop.

3F
Slang abbreviation for flip flop flying. Similar to 3D, but without the finesse.

360, 540, etc…
Number describing degrees in an arc. A 360 represents one full turn through an axis. A 360 turn, for example, is a flat turn where the aircraft does not roll its wings but rather just 'slides' through 360 degrees turning on rudder only.

For helis: A 540 stall turn, for example, describes a one and one half revolution spin at the apex of a vertical stall, which results in the helicopter resuming nose forward flight before recovery.

ATL = Adjustable Throttle Limiter
High-end feature which adjusts to bring full servo potential within the limits of bind-free servo travel. Ideal for throttle control, or for more effective braking in gas racing.

ATV/EPA = Adjustable Travel Volume/End Point Adjustment
Allows separate adjustments of maximum servo travel to both sides of neutral. Helps tailor outputs for different control styles. Please refer to this FAQ for more information.

Aileron Differential
Creating larger upward aileron travel than downward aileron travel to help minimize the model "dragging" the drooped aileron which causes a model to yaw with aileron input.

Ailerons
Hinged control surfaces located on the trailing edge of the wing, one on each side, which provide control of the airplane about the roll axis. The control direction is often confusing to first time modelers. For a right roll or turn, the right hand aileron is moved upward and the left hand aileron downward, and vice versa for a left roll or turn.

Ailevators
Twin elevator servos plugged into separate channels used to control elevator with the option to also have the 2 elevator servos act as ailerons in conjunction with the primary ailerons.

Airfoil
The shape of the wing when looking at its profile. Usually a raindrop type shape.

For helis: The rotor disk is the effective wing, and airfoil refers to the shape of the blades.

Angle of attack
The angle that the wing penetrates the air. As the angle of attack increases so does lift, up to a point (and drag).

Articulated Rotor
This is borrowed from full sized helicopters, and is a rotor head which allows the blades to flap, drag and feather.

Aspect ratio
The ratio of the wingspan to the wing's chord (depth). For sailplanes this number will be larger than sport planes, which will generally be larger than a "jet" style aircraft.

Autorotation
The ability of a rotary wing aircraft to land safely without engine power. This maneuver uses the stored energy in the rotor blades to produce lift at the end of decent, allowing the model to land safely.

Axis
The line around which a body rotates.

BEC = Battery Eliminator Circuitry
Allows receiver to draw power from a main battery pack, eliminating the need for (and weight of) a receiver battery.

Ball Bearing
Servo's output shaft is supported with bearings for increased performance and accuracy.

Ball Link
Connection using a ball, and a link which rotates on the ball. Used to connect the servo to a control surface or lever.

Backlash
Term describing the amount of play between gears, or gear mesh. If too loose, the gear can slip, or strip the teeth. Too tight, and excessive wear is caused.

Base Load Antenna
A rigid, short antenna mounted to the model. Used to replace the longer receiver antenna.

Bell and Hiller
Control system used in helicopters. Changes pitch of blades in relation to their position via a swashplate. A flybar with paddles is used to gain responsiveness. The two systems are linked with Control Levers.

Binding
What occurs when the friction at a joint is stronger than the linkage.

Boring holes in the sky
Having fun flying an R/C airplane, without any pre-determined flight pattern.

"Buddy" or Trainer Box
Two similar transmitters that are wired together with a "trainer cord." This is most useful when learning to fly -- it's the same as having dual controls. The instructor can take control by using the "trainer switch" on his transmitter.

Butterfly
Also known as crow. A mix which activates up flaperons and down inner-most flaps for gliding speed control without spoilers or airbrakes.

CA
Abbreviation for cyanoacrylate. An instant type glue that is available in various viscosities (Thin, Medium, Thick, and Gel). These glues are ideal for the assembly of wood airplanes and other materials. NOTE: Most CA glues will attack foam.

CCPM
Cyclic-Collective-Pitch-Mixing. Type of swashplate mixing which requires a radio with CCPM mixing functions. This uses three servos to control the cyclic, while all three work together to raise and lower the swashplate for collective control. Please refer to the swashplate FAQ for further information.

CG = "Center of Gravity"
For modeling purposes, this is usually considered -- the point at which the airplane balances fore to aft. This point is critical in regards to how the airplane reacts in the air. A tail-heavy plane will be very snappy but generally very unstable and susceptible to more frequent stalls. If the airplane is nose heavy, it will tend to track better and be less sensitive to control inputs, but, will generally drop its nose when the throttle is reduced to idle. This makes the plane more difficult to land since it takes more effort to hold the nose up. A nose heavy airplane will have to come in faster to land safely.

Carburetor
The part of the engine which controls the speed or throttle setting and lean/rich mixture via setting of the needle valve.

Channel
The frequency number used by the transmitter to send signals to the receiver. If radios transmit on the same frequency, or channel, glitching will occur in the active receiver on that channel. This is due to conflicting signals sent by the two radios. Flying sites should have a frequency control system to ensure that only one radio operates on any given channel at one time. This is usually a board with some type of marker for each channel. If the marker is not available, someone else is using that channel. Do not use your radio unless you are sure you are the only one on the frequency.

Channel
The number of functions your radio can control. Ex: an 8 channel radio has 8 available servo slots used for separate control surfaces or switches. These channels can also be mixed on many radios, for such functions as collective, which increases pitch when throttle is increased.

Charge Jack
The plug receptacle of the switch harness into which the charger is plugged to charge the airborne battery. An expanded scale voltmeter (ESV) can also be plugged into it to check battery voltage between flights. It is advisable to mount the charge jack in an accessible area of the fuselage so an ESV can be used without removing the wing.

Charger
Device used to recharge batteries and usually supplied with the radio if NiCad batteries are included.

Coreless motor
In a conventional servo, the motor has a steel core armature wrapped in wire that spins inside the magnets. In a coreless design, the armature uses a thin wire mesh that forms a cup that spins around the outside of the magnet eliminating the heavy steel core. A coreless motor does not have magnets as standard servo motors do, so they have a smoother, more constant, and stronger action. Regular servo motors have either 3 or 5 magnets (poles) which when the armature is between these, the servo motor is at its weakest.

Cyclic
Term used for the horizontal controls used to determine the attitude of the helicopter. Also known as elevator and aileron.

DSC = Direct Servo Control
High-end convenience feature which allows control/adjustment of servo function without sending signal through receiver. Requires optional DSC cord (FUTM4250) and DSC-compatible receiver such as R149DP and R113IP.

Dead Stick
A term used to describe unpowered flight (glide) when the engine quits running.

Dialed In
Slang term for the condition in which the model is set up to fly smoothly and predictably. This is the state where the mechanics and electronics work together to produce the best performance.

Differential
Uneven movement in each direction of a control surface. Usually used when discussing ailerons or when describing an undesired unevenness in movement of other controls.

Digital
Please see the digital servo web page: http://www.futabarc.com/servos/futm0211.html

Diode
An electronic component which only allows current to flow one direction. Protects the transmitter against reverse polarity or power surges during charging.

Dual Conversion
A type of receiver that converts the incoming frequency through two intermediate stages. This tends to eliminate the type of interference known as "image". With high-precision components, it also allows the receiver to be much more precise in selecting the incoming channel it accepts. This is what helps the receiver to be very narrow-band.

Dual Rates
A switch that can make controls more or less sensitive. Lower rates are better for beginners, who tend to overcontrol.

Elevator
Hinged control surface located at the trailing edge of the horizontal stabilizer, which provides control of the airplane about the pitch axis and causes the airplane to climb or dive. The correct direction of control is to pull the transmitter elevator control stick back, toward the bottom of the transmitter, to move the elevator upward, which causes the airplane to climb, and vice versa to dive.

Elevator-to-Flap Mixing
Used to apply flaps along with elevators to increase lift, allowing modeler to fly at slower speeds, make tighter loops or turns, etc.

Epoxy
A two-part resin/hardener glue that is extremely strong. It is generally available in 6 and 30-minute formulas. Used for critical points in the aircraft where high strength is necessary.

Expanded Scale Voltmeter (ESV)
Device used to read the battery voltage of the on- board battery pack or transmitter battery pack.

Exponential Rate
Offers servo travel that is not directly proportional to stick travel. Control response is milder below half-stick, but becomes increasing stronger as stick travel approaches 100%. Great for aerobatics and trouble situations.

FM
Frequency Modulation. This describes the mode of transmission of radio signal from transmitter to receiver.

Fail Safe
A safety feature which turns a servo to a preset position if the signal is lost or interrupted. Please refer to the FAQ for more information. Additionally, battery failsafe is a safety feature which brings the throttle servo down to idle as a warning that the receiver battery's voltage is getting dangerously low. Please refer to the FAQ for more information.

Field charger
A fast battery charger designed to work from a 12-volt power source, such as a car battery.

Flaperons
The movement of two aileron servos, both in the same direction at the same time, acting as flaps. Flaps
Hinged control surface located at the trailing edge of the wing inboard of the ailerons. The flaps are lowered to produce more aerodynamic lift from the wing, allowing a slower takeoff and landing speed. Flaps are often found on scale models, but usually not on basic trainers.

Flare
The point during the landing approach in which the pilot gives an increased amount of up elevator to smooth the touchdown of the airplane.

Flight Box
A special box used to hold and transport all equipment used at the flying field.

Flight Pack or Airborne Pack
All of the radio equipment installed in the airplane, i.e., Receiver, Servos, Battery, Switch harness.

Flutter
A phenomenon whereby the elevator or aileron control surface begins to oscillate violently in flight. This can sometimes cause the surface to break away from the aircraft and cause a crash. There are many reasons for this, but the most common are excessive hinge gap or excessive "slop" in the pushrod connections and control horns. If you ever hear a low-pitched buzzing sound, reduce throttle and land immediately.

Flyback
Decrease in angle held by a servo which is being commanded by an AVCS gyro when the input is released. For example, a rudder servo might be at full deflection when rudder input is held. When the rudder stick is released but the model has not yet turned as far as the AVCS gyro has read your input to tell it to move, the servo will continue to hold input. However, it may "flyback" or decrease the angle at which it is holding slightly. This is perfectly normal.

Frequency Control
The FCC has allowed the 72MHz (72.010 - 72.990) band to be used for R/C aircraft operations. This band is divided up into many different channels in which you can choose a radio system. You should be aware that certain areas have frequencies in which there is pager interference. This is why it is always a wise move to check with your local hobby shop to find out any channels that may be troublesome in the area you wish to fly. The FCC has allowed band 75MHz (75.410 through 75.990) for ground model use only (robots, battlebots, cars, boats), 50MHz (50.800 - 50.980) is allocated only to Amateur HAM license holders for R/C use (and only at 1W maximum power output.)

Fuselage
The body of an airplane.

Gain
Gyro sensitivity. When too low, the tail will not hold position well. When too high, the surface being dampened by the gyro will tend to wag, or hunt for center.

Glitch
Momentary radio problem that never happens unless you are over trees or a swamp.

Glow Plug
The heat source for igniting the fuel/air mixture in the engine. When starting the engine a battery is used to heat the filament. After the engine is running, the battery can be removed. The wire filament inside the plug is kept hot by the "explosions" in the engine's cylinder. See next heading and "Idle Bar" plug.

Gyro
A gyro is an electro-mechanical, or electronic device which aids in the control of an R/C model. The gyro senses motion in one axis, and directs the servo to counter that motion. The sensor, which can be a mechanical gyroscope, or an electronic piezo crystal, detects unwanted movement. The gyro then instructs the servo to counter for that motion. At all times, the radio commands will override the gyro command. The level of control the gyro had is adjusted by the GAIN setting.
Mechanical Gyro: uses a mechanical gyroscope (similar to the child's toy) to sense movement.
Piezo Gyro: uses a piezo crystal to sense movement.
Non-Heading-hold vs. heading hold: A standard (nonHH) gyro senses movement and makes an effort to counter that movement as long as it feels it. Therefore, it is NOT going to return the model to the exact heading prior to the movement. Heading Hold (or AVCS) gyros will lock the model into one position, and accurately correct for movement by sensing rate of change and returning at that same rate.
SMM technology: utilizes a microchip to sense movement and provide all readings. Experiences minimal effect from temperature change, commonly known as 'temperature drift' which affects piezo and some mechanical gyros.

Heading Hold
This describes a type of Gyro which senses rotation, and maintains direction. This is accomplished by sensing the rate of motion, and the time of motion, then compensating for the distance. While this sounds complicated, the effect is that if you have the model dialed in, and point the nose north, with a heading hold gyro on the yaw axis the model will continue to face north until you command it to yaw. See also Heading Lock. This is not recommended for aircraft use while in flight due to the requirement to use YAW (rudder) command to turn the model. Often used for ground use only for perfect take off and landing runs.

Heading Lock
Slang term for Heading Hold Gyro.

Helicopter Radio
A remote control radio system designed specifically for use with helicopter models. The helicopter radio differs from an aircraft radio in a few ways. First, the heli radio needs mixing functions specific to helicopters, and usually a minimum of five channels. Collective mixing for collective pitch helicopters is a necessity. Second is the throttle stick, which is ratcheted in airplane transmitters, will not have the clicking feel on the heli version. This is due to the precise control needed on the heli collective stick to achieve and sustain a controlled hover. The specific radio requirements will vary from user to user, and the parameters used will vary from helicopter to helicopter. Note that many radios produced have both airplane and helicopter programming in a single radio.

Hit (or to be hit)
Sudden radio interference which causes your model to fly in an erratic manner. Most often caused by someone turning on a radio that is on your frequency, but can be caused by other radio sources miles away.

Horizontal Stabilizer
The horizontal tail surface at the back of the fuselage which provides aerodynamic pitch stability to the airplane.

Idle Up
This is a setting on the transmitter which limits the throttle minimum. Particularly useful for FFF and 3D stunt flying.

Inverted
To fly a model upside-down.

Inverted Flight Control
Activates inverted flight programming for helis, which reverses the direction of the rudder, pitch and elevator servos, and sets up inverted flight pitch high-side and low-side. Inverted programming is used to allow the radio inputs to be identical to upright flight while the model is inverted. Note: this approach to hovering is seldom used. Instead, idle-ups are used and the modeler learns to understand and respond to the controls' reversal in inverted flight.

Leading Edge (LE)
The very front edge of the wing or stabilizer. This is the edge that hits the air first.

MHz = Megahertz
The unit of radio frequency. 75 MHz are surface frequencies; 72 MHz are air frequencies; 27 MHz and 50 MHz can be used for either ground or air applications. Note: Use of the 50 MHz (ham radio) band requires an FCC license.

Metal gears
Drive gears within a servo which are made of one or multiple metal types. Metal gears tend to wear more rapidly than nylon gears when in the same installation, and so require more frequent service to maintain optimum accuracy; however, metal gears are more durable in the case of severe vibration, flutter, or physical shock.

Mixing
Allows a single input to control the operation of two or more servos. Simplifies routine flying and allows more involved maneuvers -- great for intermediate-advanced fliers. For example, Flap-to-elevator mixing: Most models will change pitch upon deploying flaps (some will climb; others dive). After test flying the model and determining the direction and amount of elevator throw required to correct for this change, a pilot may set a flap-to-elevator mix to compensate. Once the mix is operating properly, when the modeler gives flap control, the radio automatically also gives the proportional amount of elevator throw, keeping the model flat and straight.

Mixing Arm
A specialized lever which has three or more pivots. The length between pivots will determine the proportion of the mix between two or more linkages.

Module
A removable/replacable plug in unit used in most complex computer radios, containing all frequency control equipment, including the crystal and all tuned components. Changing channels or bands on a modular radio requires only changing module. Changing crystals WITHIN a module to change the channel of the module itself is against FCC regulation and is not recommended. To use your transmitter on a different channel you simply purchase another module on that other channel and the radio is now fully properly tuned and safe and easy to use on that other channel as well.

Futaba module models include TP, TK, TJ, TL, and TK-FSS. For information on which module to use, see 9Z/8U modules, TF modules and aftermarket modules.
Narrow-Band
A radio with a 20 KHz band width. All Futaba radios produced 1992 or later and all Futaba FM and PCM radios ever produced are narrow band. Specific list of Futaba narrow band transmitters.

NiCad (or NiCd) = Nickel Cadmium battery
Rechargeable batteries which are typically used as power for radio transmitters and receivers.

Nitro = Nitromethane
A fuel additive which increases a model engine's ability to idle low and improves high speed performance. Ideal nitro content varies from engine to engine. Refer to the engine manufacturer's instructions for best results. Nitro content in fuel is indicated by the percent of the fuel.

Nylon gears
Drive gears within a servo are made of nylon. Nylon gears show slower wear than metal gears, but are more prone to failure due to severe vibration, flutter, or physical shock to the servo.

PA2 = Pilot Assist
Optional onboard device which uses optical sensors to correct model's orientation to upright.

PCM = Pulse Code Modulation
PCM systems use digitally encoded signals to minimize interference and provide today's most advanced R/C control. Please refer to the PCM 1024 info page and the FAQ for more information.
http://www.futaba-rc.com/glossary.html#p