Data segment

In computing, a data segment (often denoted .data) is a portion of an object file or the corresponding virtual address space of a program that contains initialized static variables, that is, global variables and static local variables. The size of this segment is determined by the size of the values in the program's source code, and does not change at run time.

The data segment is read-write, since the values of variables can be altered at run time. This is in contrast to the read-only data segment (rodata segment or .rodata), which contains static constants rather than variables; it also contrasts to the code segment, also known as the text segment, which is read-only on many architectures. Uninitialized data, both variables and constants, is instead in the BSS segment.

Historically, to be able to support memory address spaces larger than the native size of the internal address register would allow, early CPUs implemented a system of segmentation whereby they would store a small set of indexes to use as offsets to certain areas. The Intel 8086 family of CPUs provided four segments: the code segment, the data segment, the stack segment and the extra segment. Each segment was placed at a specific location in memory by the software being executed and all instructions that operated on the data within those segments were performed relative to the start of that segment. This allowed a 16-bit address register, which would normally provide 64KiB (65536 bytes) of memory space, to access a 1MiB (1048576 bytes) address space.

Data (disambiguation)

Data is uninterpreted information.

Data or DATA may also refer to:

Music

DATA (band)

DATA were an electronic music band created in the late 1970s by Georg Kajanus, creator of such bands as Eclection, Sailor and Noir (with Tim Dry of the robotic/music duo Tik and Tok). After the break-up of Sailor in the late 1970s, Kajanus decided to experiment with electronic music and formed DATA, together with vocalists Francesca ("Frankie") and Phillipa ("Phil") Boulter, daughters of British singer John Boulter.

The classically orientated title track of DATA’s first album, Opera Electronica, was used as the theme music to the short film, Towers of Babel (1981), which was directed by Jonathan Lewis and starred Anna Quayle and Ken Campbell. Towers of Babel was nominated for a BAFTA award in 1982 and won the Silver Hugo Award for Best Short Film at the Chicago International Film Festival of the same year.

DATA released two more albums, the experimental 2-Time (1983) and the Country & Western-inspired electronica album Elegant Machinery (1985). The title of the last album was the inspiration for the name of Swedish pop synth group, elegant MACHINERY, formerly known as Pole Position.

Quartz

Quartz is the second-most-abundant mineral in Earth's continental crust, after feldspar. Its crystal structure is a continuous framework of SiO₄silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO₂.

There are many different varieties of quartz, several of which are semi-precious gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Europe and the Middle East.

Etymology

The word "quartz" is derived from the German word "Quarz" and its Middle High German ancestor "twarc", which probably originated in Slavic, cf. Czech tvrdý ("hard"), Polish twardy ("hard"), Serbian and Croatian tvrd ("hard").

The Ancient Greeks referred to quartz as κρύσταλλος (krustallos) derived from the Ancient Greek κρύος (kruos) meaning "icy cold", because some philosophers (including Theophrastus) apparently believed the mineral to be a form of supercooled ice. Today, the term rock crystal is sometimes used as an alternative name for the purest form of quartz.

Crystal oscillator

A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency. This frequency is commonly used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers. The most common type of piezoelectric resonator used is the quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators, but other piezoelectric materials including polycrystalline ceramics are used in similar circuits.

Quartz crystals are manufactured for frequencies from a few tens of kilohertz to hundreds of megahertz. More than two billion crystals are manufactured annually. Most are used for consumer devices such as wristwatches, clocks, radios, computers, and cellphones. Quartz crystals are also found inside test and measurement equipment, such as counters, signal generators, and oscilloscopes.

Quartz (publication)

Quartz (qz.com) is a global digital-only business news publication. It is owned by Atlantic Media Co., the publisher of The Atlantic, National Journal, and Government Executive. Its team of 150 staff members was pulled together from prominent brands in business journalism: Bloomberg, The Wall Street Journal, The Economist, and The New York Times." The four initial sponsors of Quartz were Boeing, Chevron, Cadillac, and Credit Suisse. Quartz's core market is global business people, with its focus on international markets. Its news articles cover global economy news, ranging from geo-political conflicts to policies and regulations.

History

Name

The name "Quartz" was chosen for various reasons. The name "Quartz" is named after a type of mineral that can be found all over the world and contributed to intense geological activity. The ability of this mineral would then associate with the brand identity, creating new brand's character: global, disruptive and digital. Furthermore, "Quartz" contains two of the rarest letters in English Language, Q and Z, making it a special-looking word. When referring to the Quartz publication website, they took off all the ordinary characters leaving behind qz.com, making it a distinctive website. Also, the fact that there are fewer letters to type into a small mobile keyboard makes it a more user-friendly website.