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View Full Version : Computer used on a Boeing 747



Misty
20-01-2005, 08:35 PM
A friend of mine who captains Boeing 747's says that he thinks that the power of the computer that the 747 uses (ie for the instrument panel etc) is only about equivalent to the old 486 PC. He says that is all that seems to be needed. Scary though !!!
Misty :eek:

Catweazle
20-01-2005, 08:42 PM
I wouldn't be surprised. Apparently NASA managed to get all the way to the moon with a comp about as powerful as a Commodore C64...Scary. That could all be urban myth though.

robsonde
20-01-2005, 08:47 PM
if I remember rightly the NASA computer you talk of was more like a ZX81, 15K of ram and not much else.

with out all the crap that an OS brings in a custom solution writen for just one CPU to do just one job can be very small.

robsonde
20-01-2005, 08:49 PM
http://www.abc.net.au/science/moon/computer.htm

~sy~
20-01-2005, 09:09 PM
So what's all this about getting the latest and fastest? If a Commodore can get to the Moon, then where can my P4 go to!?!? :eek:

TonyF
20-01-2005, 09:21 PM
then where can my P4 go to!?!? :eek:

At the present rate, it can go to obsolescence in 12 months .... Sad...
But cheers anyway
TonyF

Safari
20-01-2005, 09:36 PM
A friend of mine who captains Boeing 747's says that he thinks that the power of the computer that the 747 uses (ie for the instrument panel etc) is only about equivalent to the old 486 PC. He says that is all that seems to be needed. Scary though !!!
Misty :eek:

The B747 is full of computers all for specific purposes and individually they do not have to be very powerful, they are designed to do a specific job. Why do you find it scary.
Instrument Panel you quote covers a lot of things such as Engine, Attitude, Speed, Navigation, and Auto Flight displays and they are not all controlled by the one computer and essential systems have 2 and sometimes 3 computers in case of a fault in one.

Anyone interested in the B747 Flight deck this is a good site
http://www.meriweather.com/747/747_main.html
You can click on switches and instruments and get info about what they do.

Safari
20-01-2005, 09:45 PM
If you want other aircraft cockpits and aircraft information.
http://www.meriweather.com/
http://www.meriweather.com/homepage/sitemap2.html

E|im
20-01-2005, 09:52 PM
We never went to the moon. Don't you watch the conspiracy shows? :rolleyes:

DangerousDave
20-01-2005, 10:00 PM
This guy (http://starfish.osfn.org/AGCreplica/) is my hero.

Who said the Apollo11 computer wasn't complex :P

- David

JJJJJ
21-01-2005, 05:38 AM
A friend of mine who captains Boeing 747's says that he thinks that the power of the computer that the 747 uses (ie for the instrument panel etc) is only about equivalent to the old 486 PC. He says that is all that seems to be needed. Scary though !!!
Misty :eek:

We've got a washing machine with a computer about the size of a match box.It does more work than the pile of boxes in front of me. :D

It has replaced a woman working all day in a hot steamy laundry. Just press a couple of buttons and forget it.

Isn't sceince wonderful.

Jack

sambaird
21-01-2005, 12:06 PM
We never went to the moon. Don't you watch the conspiracy shows? :rolleyes:
hes got a point there were all talking about a nasa computer that may have never existed

Misty
21-01-2005, 05:57 PM
Safari from a quick read seems pretty clued up. I have canvassed my friend by showing him the thread and he says -


The 747 has two flight managment computers. Only one runs the aircraft at any given time. Normally the left one. I don't know what the specs are, but judging by the time it takes to do basic calculations I'm not sure if they are as bright as a 486. But then for a computer the problems aren't difficult. Bearing/distance, time/speed/distance, wind calculation, basic aircraft performance taking into account weight, wind, etc. All very basic and a 486 would eat it for lunch.

Seems pretty clear to me !
Misty :)

Safari
21-01-2005, 07:33 PM
Thats fair enough if you are just talking about FMC's and the speed they do the calculations, and I am not disputing how fast they display the information on the CDU.
To do to all the calculations they have to gather information from other sources and computers and they are not a standalone computer as you know it so it is hard to compare it with anything.

The only reason I responded was that you mentioned Instrument Panel (in fact the Flight Management Computer Display you now mention is not even on the instrument panel so you can see I was confused about what you were referring to) and I was just pointing out there are many imputs to the various controls and indications from other computers and the FMC's require input from some of these as well to do its calculations.
Some other computers that give control and indication are -
Central Air Data Computer
Flight Director Computer
Auto Throttle Computer
Yaw Danper Computer
Roll Computer
Pitch Computer

I don't disagree with anything your friend has said, he is the Captain and obviously knows what he is talking about.

Graham L
22-01-2005, 03:08 PM
You don't need much of a computer to fly. People can do it.

The Space Shuttle computers are very small. They will hold only one "flight phase" at a time, so before going to a new phase, the appropriate programme is loaded from a tape drive.

They will probably still carry an extra "get you home" computer. That's one which isn't plugged in unless it's needed. It's loaded before launch with the code to land the Shuttle. (It can't handle holes in the insulation and melted wings.)

The control system works on a 40 ms clock. Mesurements from sensors are fed in on one tick, the control outputs go out on the next. That's 25 "operations" a second.

The very first launch was held up for a couple of hours. Some of the extensive testing had left the In/Out toggle (40 ms clock) in the wrong state. Most of the two hours was spent convincing the managers that this "fault" (which had been trapped) could be fixed by the highly technical operation of turning the computer off then on again.

Of course there's no operating system to clog up memory, introduce errors, and slow things down generally. There's a programme loader.

The code is written carefully. It is checked thoroughly. It's small, it's very reliable. There have been no errors found.

Gerrypics
22-01-2005, 10:25 PM
Cassini-Huygens Probe that has just landed on Titan (one of saturns moons)
must have a pre windows 98 on board not to mention their imaging gear.

E|im
22-01-2005, 10:56 PM
Cassini-Huygens Probe that has just landed on Titan (one of saturns moons)
must have a pre windows 98 on board not to mention their imaging gear.
NASA would nuke itself before putting that poor software on any of their computers.

That probe would have been dead in space about 30mins after launch with Win98 on it. 5mins if it was WinME.