PDP11 for full flight simulator in '70-'80s

[Qwseyvnd]

How did it able to run better flight model than x-plane 10 and FSX with much, much lower performance ?

Regards from Qwseyvnd.

[Qwseyvnd]

No anyone know ?

[dnoize]

i dont think many here know what a pdp11 is.

Anyway, sims back then, in the late 70's early 80's werent as sophisticated as they are now.
flightmodel really wasnt that realistic.
Visuals were horrible and resembled the game Pong more than the Visuals of the sims we have at home. Back then the Visuals werent much more than a bunch of dots visualizing a runway.

It was more about procedure training than about visual realism.

[Qwseyvnd]

So visual was not good but the physics was good enough ?

[dnoize]

both do not compare to todays standards.
Visuals were nightvision only (and bad one too, to add to that).
There is no 180 degrees view.

A typical sim usually had around 4 pdp/11's in te machine room.
Most of te number crunching was for driving the instruments/logics.

the computers are not powerfull enough for accurate flightmodel.

Back in those days it was more about procedure training than about real flight physics.

check these guys:

http://www.dc10.no/

they used to run a 35 yr old DC10 sim powered by PDP/11 , but i dont know the status of their project today.

[Qwseyvnd]

I know about the DC10 in Norway. I live in Norway.

Which equiment does today full flight simulators using ? Their own computer or a standard intel computer ? How do they operate a perfect flight model ?

[xplanematt]

Sims in the 80s/90s used proprietary systems, usually based on various high-powered specialty computers of the day. However, nowadays you will see frequent reference to the term COTS components: Commercial Off The Shelf. This refers to using standard PC equipment, for example. I've seen a relatively recent sim running a real-time Windows 2000 kernel. As I recall, a lot of the instrument interfacing was being handled by an FPGA, but I saw fairly "normal" looking PC towers as well. Some of the other sims at that facility are running Redhat Linux also (presumably a real-time kernel as well, though I am not 100% positive on this).

I think the biggest key to the newer systems is the need for absolutely correct timing, which is why they are using real-time kernels. IMO a RT build has little advantage to us recreational simmers (you'd probably never notice the difference in flight), with a number of added complexities. But I must admit, the software they were running on Win2k was pretty cool: it broke up the various elements of the sim into discrete processes that could be managed individually. Each process had a frequency setting next to it...so the visuals might update at 25hz (yep, 25 fps is all they use), the switch inputs at 10hz, GPS updates at 5hz, etc. The whole system was very fascinating, and actually I think I will do something similar with the process scheduling on my X-Plane plugin for the Sabreliner (when hooking into X-Plane's API, there are very real performance advantages to be realized by being able to easily and quickly change the update rates of various parts of your plugin, to "tune" the plugin to get the best performance while still updating things fast enough).

Matt

[geerol]

How did it able to run better flight model than x-plane 10 and FSX with much, much lower performance ?

Regards from Qwseyvnd.

Ran into this today....
Well, I have been contributing to Norwegian DC-10 project with focus on PDP-11s (hardware & software) since 2008. Before that I did not believe a Real World Sim could run on that kind of computers.

It actually takes two PDP-11s to run the original Link Miles software, which is about 500 Kbyte in total. You should realise:

1. it does not mimick any instrument (graphics!) as that is done by real hardware in the cockpit.
2. the DC-10 flight model has been FAA certified in the past, including simulation of all circuit breakers (and I mean all!), electrical and hydraulic systems, Flight Engineer panel etc not to forget the Trainer Station etc.
3. Visual system (cockpit view) is not done by these two hardworking machines: original/defunct Night Vision System, but replaced by software to map position info (and more) into FS9 or FSX (a plane in slew-mode).

For the curious readers:

• Slides with project overview: http://geerol.home.xs4all.nl/filestore/FSW-111105.pdf
• A very popular demo movie: http://www.youtube.com/watch?v=Y-DpcvY4aBk
• About Daylight Vision System: http://geerol.home.xs4all.nl/filestore/DVS-project.pdf

Any questions -- feel free to ask....

Geert

[geerol]

This is intended to delete my duplicate post.

[geerol]

This is intended to delete my duplicate post.