Single UNIX Specification

The Single UNIX Specification (SUS) is the collective name of a family of standards for computer operating systems, compliance with which is required to qualify for to use the "UNIX" trademark. The core specifications of the SUS are developed and maintained by the Austin Group, which is a joint working group of IEEE, ISO JTC 1 SC22 and The Open Group. If an operating system is submitted to The Open Group for certification, and passes conformance tests, then it is termed to be compliant with a UNIX standard such as UNIX 98 or UNIX 03.

Very few BSD and Linux-based operating systems are submitted for compliance with the Single UNIX Specification, although system developers generally aim for compliance with POSIX standards, which form the core of the Single UNIX Specification.

History

1980s: Motivation

The SUS emerged from a mid-1980s project to standardize operating system interfaces for software designed for variants of the Unix operating system. The need for standardization arose because enterprises using computers wanted to be able to develop programs that could be used on the computer systems of different manufacturers without reimplementing the programs. Unix was selected as the basis for a standard system interface partly because it was manufacturer-neutral.

Year 2038 problem

The Year 2038 problem is an issue for computing and data storage situations in which time values are stored or calculated as a signed 32-bit integer, and this number is interpreted as the number of seconds since 00:00:00 UTC on 1 January 1970 ("the epoch"). Such implementations cannot encode times after 03:14:07 UTC on 19 January 2038 (21 years' time), a problem similar to but not entirely analogous to the "Y2K problem" (also known as the "Millennium Bug"), in which 2-digit values representing the number of years since 1900 could not encode the year 2000 or later. Most 32-bit Unix-like systems store and manipulate time in this "Unix time" format, so the year 2038 problem is sometimes referred to as the "Unix Millennium Bug" by association.

Technical cause

The latest time that can be represented in Unix's signed 32-bit integer time format is 03:14:07 UTC on Tuesday, 19 January 2038 (2,147,483,647 seconds after 1 January 1970). Times beyond that will "wrap around" and be stored internally as a negative number, which these systems will interpret as having occurred on 13 December 1901 rather than 19 January 2038. This is caused by integer overflow. The counter "runs out" of usable bits, "increments" the sign bit instead, and reports a maximally negative number (continuing to count up, toward zero). Resulting erroneous calculations on such systems are likely to cause problems for users and other relying parties.

Nitro

Chemistry

Entertainment

Nitroplus

Nitroplus Co., Ltd., stylized as nitro+, is a Japanese visual novel computer software company that has developed a number of visual novels, including eroge. They also have been collaborating with TYPE-MOON (another developer) to create the light novel series Fate/Zero. Their works usually have dark themes such as reanimation of the dead and murder. They also have a branch of the company called Nitro+Chiral, which focuses on Boys' Love visual novels. Writers aligned with the company, such as Gen Urobuchi, have also contributed to various manga, anime, novel, and television works.

Super Sonico is the mascot of Nitroplus' annual music festival event, "Nitro Super Sonico", since 2006. Nitroplus has held their music festival every year since 2000.

List of works

Nitro (wireless networking)

Nitro from Conexant (originally developed by Intersil) is a proprietary 802.11g performance enhancement technology introduced in 2003 as part of the PRISM chipset. The first implementation was designed to help compensate for the performance loss of higher-speed 802.11g devices when they share a wireless network with slower 802.11b devices.

Later implementations are marketed as Nitro MX Xtreme which adds proprietary frame-bursting, compression and point-to-point side session technology for a claimed 140 Mbit/s throughput transmission speed. The point-to-point side session technology, called DirectLink, creates a connection between clients or from a client to a media source, such as a media server, and avoids the access point. It does this while staying in 802.11 Infrastructure mode so the client can continue to utilize access point-based security and power-savings.

Alternatives

Nitro is one of several competing incompatible proprietary extension approaches that were developed to increase performance of 802.11g wireless devices, such as 125 High Speed Mode from Broadcom, Super G (or "108 Mbit/s" technology) from Atheros, and MIMO-based extensions from Airgo Networks.