Posts filled under #lahmacun

An extract on #lahmacun

Viewed from near the Alpha Centauri system, the sky would appear very much as it does for an observer on Earth, except that Centaurus would be missing its brightest star. The Sun would be a yellow star of an apparent visual magnitude of +0.5 in eastern Cassiopeia, at the antipodal point of Alpha Centauri's current right ascension and declination, at 02h 39m 35s +60 50 (2000). This place is close to the 3.4-magnitude star Cassiopeiae. Because of the placement of the Sun, an interstellar or alien observer would find the \/\/ of Cassiopeia had become a /\/\/ shape nearly in front of the Heart Nebula in Cassiopeia. Sirius lies less than a degree from Betelgeuse in the otherwise unmodified Orion and with a magnitude of 1.2 is a little fainter than from Earth but still the brightest star in the Alpha Centauri sky. Procyon is also displaced into the middle of Gemini, outshining Pollux, whereas both Vega and Altair are shifted northwestward relative to Deneb (which barely moves, due to its great distance), giving the Summer Triangle a more equilateral appearance.

The custom chipset at the core of the Amiga design appeared in three distinct generations, with a large degree of backward-compatibility. The Original Chip Set (OCS) appeared with the launch of the A1000 in 1985. OCS was eventually followed by the modestly improved Enhanced Chip Set (ECS) in 1990 and finally by the partly 32-bit Advanced Graphics Architecture (AGA) in 1992. Each chipset consists of several coprocessors which handle graphics acceleration, digital audio, direct memory access and communication between various peripherals (e.g., CPU, memory and floppy disks). In addition, some models featured auxiliary custom chips which performed tasks such as SCSI control and display de-interlacing.

Long-time Amiga developer MacroSystem entered the Amiga-clone market with their DraCo non-linear video editing system. It appears in two versions, initially a tower model and later a cube. DraCo expanded upon and combined a number of earlier expansion cards developed for Amiga (VLabMotion, Toccata, WarpEngine, RetinaIII) into a true Amiga-clone powered by the Motorola 68060 processor. The DraCo can run AmigaOS 3.1 up through AmigaOS 3.9. It is the only Amiga-based system to support FireWire for video I/O. DraCo also offers an Amiga-compatible Zorro-II expansion bus and introduced a faster custom DraCoBus, capable of 30 MB/sec transfer rates (faster than Commodore's Zorro-III). The technology was later used in the Casablanca system, a set-top-box also designed for non-linear video editing. In 1998, Index Information released the Access, an Amiga-clone similar to the Amiga 1200, but on a motherboard which could fit into a standard 5" drive bay. It features either a 68020 or 68030 CPU, with a redesigned AGA chipset, and runs AmigaOS 3.1. In 1998, former Amiga employees (John Smith, Peter Kittel, Dave Haynie and Andy Finkel to mention few) formed a new company called PIOS. Their hardware platform, PIOS One, was aimed at Amiga, Atari and Macintosh users. The company was renamed to Met@box in 1999 until it folded. The NatAmi (short for Native Amiga) hardware project began in 2005 with the aim of designing and building an Amiga clone motherboard that is enhanced with modern features. The NatAmi motherboard is a standard Mini-ITX-compatible form factor computer motherboard, powered by a Motorola/Freescale 68060 and its chipset. It is compatible with the original Amiga chipset, which has been inscribed on a programmable FPGA Altera chip on the board. The NatAmi is the second Amiga clone project after the Minimig motherboard, and its history is very similar to that of the C-One mainboard developed by Jeri Ellsworth and Jens Schnfeld. From a commercial point of view, Natami's circuitry and design are currently closed source. One goal of the NatAmi project is to design an Amiga-compatible motherboard that includes up-to-date features but that does not rely on emulation (as in WinUAE), modern PC Intel components, or a modern PowerPC mainboard. As such, NatAmi is not intended to become another evolutionary heir to classic Amigas, such as with AmigaOne or Pegasos computers. This "purist" philosophy essentially limits the resulting processor speed but puts the focus on bandwidth and low latencies. The developers also recreated the entire Amiga chipset, freeing it from legacy Amiga limitations such as two megabytes of audio and video graphics RAM as in the AGA chipset, and rebuilt this new chipset by programming a modern FPGA Altera Cyclone IV chip. Later, the developers decided to create from scratch a new software-form processor chip, codenamed "N68050" that resides in the physical Altera FPGA programmable chip. In 2006, two new Amiga clones were announced, both using FPGA based hardware synthesis to replace the Amiga OCS custom chipset. The first, the Minimig, is a personal project of Dutch engineer Dennis van Weeren. Referred to as "new Amiga hardware", the original model was built on a Xilinx Spartan-3 development board, but soon a dedicated board was developed. The minimig uses the FPGA to reproduce the custom Denise, Agnus, Paula and Gary chips as well as both 8520 CIAs and implements a simple version of Amber. The rest of the chips are an actual 68000 CPU, ram chips, and a PIC microcontroller for BIOS control. The design for Minimig was released as open-source on July 25, 2007. In February 2008, an Italian company Acube Systems began selling Minimig boards. A third party upgrade replaces the PIC microcontroller with a more powerful ARM processor, providing more functionality such as write access and support for hard disk images. The Minimig core has been ported to the FPGArcade "Replay" board. The Replay uses an FPGA with about 3 times more capacity and which does support the AGA chipset and a 68020 soft core with 68030 capabilities. The Replay board is designed to implement many older computers and classic arcade machines. The second is the Clone-A system announced by Individual Computers. As of mid 2007 it has been shown in its development form, with FPGA-based boards replacing the Amiga chipset and mounted on an Amiga 500 motherboard.