Exos

Exos may refer to:

Rockets

Software

RM-86 Exos

The Exos, originally designated RM-86 and later PWN-4, was a sounding rocket developed by the University of Michigan and NACA for use by the United States Air Force.

History

Developed by the University of Michigan for use by the Air Force Cambridge Research Center, Exos used a three-stage configuration, consisting of a first-stage rocket from an Honest John rocket, a second stage from a Nike-Ajax surface-to-air missile, and a Thiokol XM19 upper stage. It was designated XRM-86 in April 1959, and redesignated PWN-4A in June 1963.

Utilising a rail launcher, the first launch of a full Exos vehicle took place in June 1958, launched from the Wallops Flight Facility. Eight operational launches took place between 1960 and 1965, launched from Eglin Air Force Base.

Launch history

References

Exokernel

Exokernel is an operating system kernel developed by the MIT Parallel and Distributed Operating Systems group, and also a class of similar operating systems.

Operating System Kernels generally present the hardware-resources to applications through high level abstractions such as the (virtual) file-system. The idea behind exokernels is to force as few abstractions as possible on developers, enabling them to make as many decisions as possible about hardware abstractions. Exokernels are tiny, since functionality is limited to ensuring protection and multiplexing of resources, which are vastly simpler than conventional microkernels' implementation of message passing and monolithic kernels' implementation of abstractions.

Implemented applications are called library operating systems; they may request specific memory addresses, disk blocks, etc. The kernel only ensures that the requested resource is free, and the application is allowed to access it. This low-level hardware access allows the programmer to implement custom abstractions, and omit unnecessary ones, most commonly to improve a program's performance. It also allows programmers to choose what level of abstraction they want, high, or low.

Begin

Begin or Bégin may refer to:

People

Music

Other

See also

Begin (David Archuleta album)

Begin (stylized as BEGIN.) is the fifth studio album by American singer-songwriter David Archuleta. The album is composed of nine cover songs and an exclusive original track sung by Archuleta himself.

Album information

The album was released on August 7, 2012, under Deseret Book's label, Highway Records, (formerly known as Lightwave Records), a subsidiary of Shadow Mountain. The album consists of ten tracks, nine of which are cover songs by Archuleta and one of them, titled "Broken" is an entirely new song co-written and sung by Archuleta himself. Archuleta said about the album "I wanted to still be able to give people an idea of what it's like for me and find songs that they can connect with as well." A music video for the song "Everybody Hurts" was released on August 23. The video was directed by Jed Wells and features footage from Archuleta recording the song in the studio the day before he left on his mission.

The album was released in Malaysia through Sony Music and in Philippines by Ivory Records.

Begin (video game)

Begin, A Tactical Starship Simulation is a computer game which was released in 1984 and consists of combat between spaceships. It is a tactical starship simulator where the player commands a fleet of ships against an alien force. In the early 1990s, it was followed by Begin 2. Begin 3 for Windows was released in March 2009. In 1996, Michael Feir stated that Begin 2 is "the best and most detailed simulator accessible to the blind."

The game is set in the Star Trek universe. Players can play as the Federation, Klingon, Romulans or Orion Pirates. Various weapons and functions are included, such as phasers, photon torpedeos and tractor beams. According to PC-SIG, the "computer strategy is quite effective."

Begin 2

Begin 2 is a tactical starship simulator game set in the Star Trek universe released in 1991. It is the sequel to Begin. The screen is similar to the one in Begin. The main difference is that the sequel featured VGA graphics whereas the original used pure ASCII screen characters (text mode). Extra ships and weapons were added as well. However, each ship is individually represented in the game, and can be individually operated and commanded by the player. Each ship has a unique set of weapons and resources. As with the first game, one of the most notable features of this game is its highly mathematical nature, and its lack of random factors.