Original Chip Set

The Original Chip Set (OCS) was a chipset used in the earliest Commodore Amiga computers and defined the Amiga's graphics and sound capabilities. It was succeeded by the slightly improved Enhanced Chip Set (ECS) and greatly improved Advanced Graphics Architecture (AGA).

The original chipset appeared in Amiga models built between 1985 and 1990: the Amiga 1000, Amiga 2000, Amiga CDTV, and Amiga 500.

Overview of chips

The chipset which gave the Amiga its unique graphics features consists of three main "custom" chips; Agnus, Denise, and Paula. Both the original chipset and the enhanced chipset were manufactured using NMOS logic technology by Commodore's chip manufacturing subsidiary, MOS Technology. According to Jay Miner, the OCS chipset was fabricated in 5 µm manufacturing process while AGA Lisa was implemented in 1.5 µm process. All three custom chips were originally packaged in 48-pin DIPs; later versions of Agnus, known as Fat Agnus, were packaged in an 84-pin PLCC.

Agnus is the central chip in the design. It controls all access to chip RAM from both the central 68000 processor and the other custom chips, using a complicated priority system. Agnus includes sub-components known as the blitter (fast transfer of data in memory without the intervention of the processor) and the Copper (video-synchronized co-processor). The original Agnus can address 512 KB of chip RAM. Later revisions, dubbed 'Fat Agnus', added 512 KB pseudo-fast RAM, which for ECS was changed to 1 MB (sometimes called 'Fatter Agnus') and subsequently to 2 MB chip RAM.

BPM 37093

BPM 37093 (V886 Centauri) is a variable white dwarf star of the DAV, or ZZ Ceti, type, with a hydrogen atmosphere and an unusually high mass of approximately 1.1 times the Sun's. It is about 50 light-years from Earth, in the constellation Centaurus, and vibrates; these pulsations cause its luminosity to vary. Like other white dwarfs, BPM 37093 is thought to be composed primarily of carbon and oxygen, which are created by thermonuclear fusion of helium nuclei in the triple-alpha process.

In the 1960s, it was predicted that as a white dwarf cools, its material should crystallize, starting at the center. When a star pulsates, observing its pulsations gives information about its structure. BPM 37093 was first observed to be a pulsating variable in 1992, and in 1995 it was pointed out that this yielded a potential test of the crystallization theory. In 2004, Antonio Kanaan and a team of researchers of the Whole Earth Telescope estimated, on the basis of these asteroseismological observations, that approximately 90% of the mass of BPM 37093 had crystallized. Other work gives a crystallized mass fraction of between 32% and 82%. Any of these estimates would result in a total crystalline mass in excess of 5×10²⁹ kilograms.

Esox

Esox is a genus of freshwater fish, the only living genus in the family Esocidae—the esocids which were endemic to North America and Eurasia during the Paleogene through present.

The species of this genus are known as pike and pickerel. The type species is E. lucius, the northern pike.

The big pike species are native to the Palearctic and Nearctic ecozones, ranging across northern North America and from Western Europe to Siberia in Eurasia.

Pikes have the elongated, torpedo-like form of predatory fishes, with sharply pointed heads and sharp teeth. Their coloration is typically grey-green with a mottled or spotted appearance with stripes along their backs, providing camouflage among weeds. Individual pike marking patterns are unique, like fingerprints. Pike can grow to a maximum recorded length of 1.83 m (6 ft), reaching a maximum recorded weight of 35 kg (77 lb).

Species

There currently seven recognized species in this genus:

Dorothea Weber

Dorothea Weber was a 190 GRT three-masted Schooner that was built in 1922 as the barge Lucy by J Oelkers, Hamburg. She was later renamed Midgard I, Midgard IV and then Elisabeth before a sale in 1935 saw her fitted with a diesel engine and renamed Dorothea Weber. She was seized by the Allies in May 1945 at Guernsey, passed to the Ministry of War Transport (MoWT) and renamed Empire Cononley.

In 1947, she was sold into merchant service and renamed Coverack. A further sale in 1953 saw her renamed River Witham. She served until 1959 when she ran aground off Lowestoft. Although she was refloated, she capsized and sank off the Inner Dowsing Light Vessel.

Description

The ship was built by J Oelkers, Hamburg. She was launched in 1922.

The ship was 105 feet 7 inches (32.18 m) long, with a beam of 24 feet 9 inches (7.54 m) and a depth of 8 feet 1 inch (2.46 m). The ship had a GRT of 190 and a NRT of 100.

As built, the ship was propelled by sails alone. A diesel engine was fitted in 1935 and this was replaced by another engine in 1951.