Dogfight is a demonstration program initially written by Gary Tarolli (later founder of 3dfx) at Silicon Graphics, Inc in the summer of 1983.

[1][2] It represents landmarks in two key areas of Internet development: games and multicasting, and notable advancement in creating rendered virtual environments.

The intention was for the user to be able to record the paths of several aircraft, and then, by replaying them simultaneously, to be able to display complex aerial formations with multiple planes.

Such a display was commonly used in military aircraft and would allow for a larger view, but at the cost of a slower update rate.

[7][8][9] Information was transmitted via broadcast packets and at frame rate, meaning that the program made intensive use of network resources and even a small number of players was capable of saturating an Ethernet.

[10][11] Some Usenet posts claimed that the code was not supplied standalone, but as part of a "Software Exchange Release Tape".

Due to the availability of the source code, various SGI customers created and distributed their own unofficial modifications to the original flight program.

A version replacing the UDP broadcast with point-to-point communication between two hosts was created at the Lund Institute of Technology in Sweden.

[23][24] This was probably Ron Natalie's air traffic control server, running on the BRL's forked version of dog.

In a 1992 thread on the rec.aviation.simulators Usenet group,[25] a list of available flight simulators included a port of dog/flight to pixrect - a "low-level raster operations library for writing device-independent applications for Sun products.

In a 1990 post to comp.sys.sgi,[27] a Sun port was mentioned which "runs reasonably well on a colour GX Sparcstation although it doesn't fill the polygons so a lot of the realism is lost".

In a later post,[27] he stated that he had been informed by SGI that the source code should not have been made publicly available, and was distributed in violation of an NDA.

In a 1993 Usenet posting, one user mentioned having seen a version of flight with X-wing and TIE fighter models in the autumn 1987 issue of SGI's house magazine "IRIS Universe".

[28] In a reply, a user from NASA's Langley Research Center said that they had had such a version running on an SGI 3130, and that as well as new vehicles there were also new weapons for some craft.

In a 1994 Usenet post, another user claimed authorship of the modified version, and offered to supply source code "for a price".

In an earlier Usenet posting, another user had claimed that the Klingon craft could cause lasting terrain damage with its weapons, leaving "craters in the Earth".

[30] Asked about this version, flight lead developer Rob Mace said that it had come "from a university", and that due to the copyrighted status of Snoopy and the sci-fi vehicles, SGI could not legally supply copies of it.

[38][39] In this revision, the SAMs could not be intercepted, had higher acceleration than the player's sidewinders, and would detonate themselves after 10 seconds when they ran out of fuel.

Two users complained about the game's stall/spin physics, arguing that stalls and spins did not occur as often as they would in real life, or in as many circumstances.

The calculations involved in modelling minor stalls would also be intensive and complicated enough to cause significant in-game slowdown.

[45] At least one user felt that the criticism levelled at Gary for the in-game physics was unfair, noting that flight and dog were intended primarily as fun games, not as precise simulations.

The software written to perform this operation uses UDP/IP to capture the SG broadcast packets and saves them to a disk file.

Due to the presence of the head-mounted display, the PC also had to host a device to track user head movements.

Problems were mentioned with the PC's graphics software being unable to handle the F-15 model, although this may only have applied if another plane was also present.

The PC's performance was also compared to that of the Silicon Graphics IRIS 4D/85GT with an unmodified version of the flight simulator.

Furthermore, the PC Reality board was not able to support the polygon count or frame rate claimed, and some advertised capability was missing.

Only 4 frames per second were obtained, and even in tests with "an out-the-window view without the runway, buildings, or other terrain visible" no more than 10 fps could be achieved.

This meant that simply repeating the same set of inputs across multiple runs of the flight simulator would not be guaranteed to give the same results.

The researchers hoped that the work they had done in addressing this problem would later be applicable to real-world situations, such as the effects of varying wind conditions on a plane.