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Amiga 3000
The Commodore Amiga 3000, or A3000, is a personal computer released by Commodore in June 1990. It features improved processing speed, improved graphics rendering, and a new revision of the operating system. It is the successor to the Amiga 2000. Its predecessors, the Amiga 500, 1000 and 2000, share the same fundamental system architecture and consequently perform without much variation in processing speed despite considerable variation in purchase price. The A3000 however, was entirely reworked and rethought as a high-end workstation. The new Motorola 32-bit 68030 CPU, 68882 math co-processor, and 32-bit system memory increase the integer processing speed by a factor of 5 to 18, and the floating-point processing speed by a factor of 7 to 200 times. The new 32-bit Zorro III expansion slots provide for faster and more powerful expansion capabilities. In common with earlier Amigas the 3000 runs a 32-bit operating system called AmigaOS. Version 2.0 is generally considered to have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola 68030
The Motorola 68030 ("''sixty-eight-oh-thirty''") is a 32-bit microprocessor in the Motorola 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 (pronounced ''oh-three-oh'' or ''oh-thirty''). The 68030 is essentially a 68020 with a memory management unit (MMU) and instruction and data caches of 256 bytes each. It added a burst mode (computing), burst mode for the caches, where four longwords can be loaded into the cache in a single operation. The MMU was mostly compatible with the external Motorola 68851, 68851 that would be used with the 68020, but being internal allowed it to access memory one cycle faster than a 68020/68851 combo. The 68030 did not include a built-in floating-point unit (FPU), and was generally used with the Motorola 68881, 68881 and the faster Motorola 68882, 68882. The addition of the FPU was a major d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amiga 3000T
The Amiga 3000T is a computer manufactured by Commodore. It is closely related to the Amiga 3000, although it came in a tower case which offers greater expandability. The case for the prototype, the 3500, was derived from Commodore's PC compatible line. Like the desktop variant it is based upon, the A3000T has a CPU FAST slot which allows for processor upgrades. Later models were offered with a 68040 CPU in this slot, and third-party upgrades can be used to add a PowerPC processor. The A3000T has a variety of drive bays two 3.5-inch drives and one 5.25-inch half-height drive, mounted horizontally; and two 5.25-inch half-height drives mounted vertically. Inside, behind these bays, there is space for two more, internal, 5.25-inch half-height drives. The available drive bays make it possible to internally install up to seven drives in the A3000T. The A3000T's specifications closely resemble the horizontal-cased Amiga 3000, but the motherboard has been heavily redesigned. As a r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DE-9 Connector
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems. Description, nomenclature, and variants A D-sub contains two or more parallel rows of pins or sockets usually surrounded by a D-shaped metal shield that provides mechanical support, ensures correct orientation, and may screen against electromagnetic interference. D-sub connectors have gender: parts with pin contacts are called ''male connectors'' or ''plugs'', while those with socket contacts are called ''female connectors'' or ''sockets''. The socket's shield fits tightly inside the plug's shield. Panel mounted connectors usually have #4-40 UNC (as designated with the Unified Thread Standard) jackscrews that accept screws on the cable end connector cover that are used for locking the connectors together and offering mechanical strain relief, and can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Release Life Cycle
A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help improve the software or fix software bugs still present in the software. There are several models for such a life cycle. A common method is that suggested by Microsoft, which divides software development into five phases: Pre-alpha, Alpha, Beta, Release candidate, and Stable. Pre-alpha refers to all activities performed during the software project before formal testing. The alpha phase generally begins when the software is feature complete but likely to contain several known or unknown bugs. The beta phase generally begins when the software is deemed feature complete, yet likely to contain several known or unknown bugs. Software in the production phase will generally have many more bugs in it than completed software, as well as speed/performan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Random Access Memory
Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxide-semiconductor (MOS) technology. While most DRAM memory cell designs use a capacitor and transistor, some only use two transistors. In the designs where a capacitor is used, the capacitor can either be charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1. The electric charge on the capacitors gradually leaks away; without intervention the data on the capacitor would soon be lost. To prevent this, DRAM requires an external ''memory refresh'' circuit which periodically rewrites the data in the capacitors, restoring them to their original charge. This refresh process is the defining characteristic of dynamic random-access memory, in contrast to static random-access memory (SRA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zig-zag In-line Package
The zig-zag in-line package (ZIP) is a packaging technology for integrated circuits. It was intended as a replacement for dual in-line packaging (DIL or DIP). A ZIP is an integrated circuit encapsulated in a slab of plastic with 16, 20, 28 or 40 pins, measuring (for the ZIP-20 package) about 3 mm x 30 mm x 10 mm. The package's pins protrude in two rows from one of the long edges. The two rows are staggered by 1.27 mm (0.05"), giving them a zig-zag appearance, and allowing them to be spaced more closely than a rectangular grid would allow. The pins are inserted into holes in a printed circuit board, with the packages standing at right-angles to the board, allowing them to be placed closer together than DIPs of the same size. ZIPs have now been superseded by surface-mount packages such as the thin small-outline packages ( TSOPs), but are still in use. The quad in-line package uses a smilar staggered semiconductor package design. High-power devices (such as hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual In-line Package
In microelectronics, a dual in-line package (DIP or DIL), is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (PCB) or inserted in a socket. The dual-inline format was invented by Don Forbes, Rex Rice and Bryant Rogers at Fairchild R&D in 1964, when the restricted number of leads available on circular transistor-style packages became a limitation in the use of integrated circuits. Increasingly complex circuits required more signal and power supply leads (as observed in Rent's rule); eventually microprocessors and similar complex devices required more leads than could be put on a DIP package, leading to development of higher-density chip carriers. Furthermore, square and rectangular packages made it easier to route printed-circuit traces beneath the packages. A DIP is usually referred to as a DIP''n'', where ''n'' is the total number of pins. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCSI
Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interfaces. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. The initial Parallel SCSI was most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives, although not all controllers can handle all devices. The ancestral SCSI standard, X3.131-1986, generally referred to as SCSI-1, was published by the X3T9 technical committee of the American National Standards Institute (ANSI) in 1986. SCSI-2 was published in August 1990 as X3.T9.2/86-109 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Memory Access
Direct memory access (DMA) is a feature of computer systems and allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed input/output, it is typically fully occupied for the entire duration of the read or write operation, and is thus unavailable to perform other work. With DMA, the CPU first initiates the transfer, then it does other operations while the transfer is in progress, and it finally receives an interrupt from the DMA controller (DMAC) when the operation is done. This feature is useful at any time that the CPU cannot keep up with the rate of data transfer, or when the CPU needs to perform work while waiting for a relatively slow I/O data transfer. Many hardware systems use DMA, including disk drive controllers, graphics cards, network cards and sound cards. DMA is also used for intra-chip data transfer in multi-core processors. Computers that have DMA channels can trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amiga Enhanced Chip Set
The Enhanced Chip Set (ECS) is the second generation of the Amiga computer's chipset, offering minor improvements over the original chipset (OCS) design. ECS was introduced in 1990 with the launch of the Amiga 3000. Amigas produced from 1990 onwards featured a mix of OCS and ECS chips, such as later versions of the Amiga 500 and the Commodore CDTV. Other ECS models were the Amiga 500+ in 1991 and lastly the Amiga 600 in 1992. Notable improvements were the '' Super Agnus'' and the ''HiRes Denise'' chips. The sound and floppy controller chip, '' Paula'', remained unchanged from the OCS design. Super Agnus supports 2 MB of Chip RAM, whereas the original Agnus/''Fat Agnus'' and subsequent ''Fatter Agnus'' can address 512 KB and 1 MB, respectively. The ECS Denise chip offers ''Productivity'' (640×480 non-interlaced) and ''SuperHiRes'' (1280×200 or 1280×256) display modes (also available in interlaced mode), which are however limited to only 4 on-screen colors. Essentially, a 35 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh Quadra 840AV
The Macintosh Quadra 840AV is a personal computer designed, manufactured, and sold by Apple Computer from July 1993 to July 1994. It was introduced alongside the Centris 660AV, where "AV" signifies audiovisual capabilities, such as video input and output, telecommunications, speech recognition, and enhanced audio. The 840AV has the same mini-tower form factor as the Quadra 800, with a faster Motorola 68040 processor. The Quadra 840AV was discontinued shortly after the introduction of the PowerPC-based Power Macintosh. The Power Macintosh 8100/80AV provides the same functionality in the same form factor, and had a significantly higher price point. The 7100/66AV was priced comparably to the 840AV but in a IIvx-style desktop case. Hardware At launch, Quadra 840AV's 40 MHz Motorola 68040 CPU and interleaved RAM made it the fastest Macintosh available, topping both the nominally higher-end Quadra 950 and the Quadra 800 by 7 MHz. It remains both the fastest Quadr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh Quadra 660AV
The Macintosh Quadra 660AV, originally sold as the Macintosh Centris 660AV, is a personal computer designed, manufactured and sold by Apple Computer from July 1993 to September 1994. It was introduced alongside the Quadra 840AV; the "AV" after both model numbers signifies video input and output capabilities and enhanced audio. The 660AV was discontinued a few months after the introduction of the Power Macintosh 6100/60AV. Apple sold a Power Macintosh Upgrade Card that upgrades the 660AV to match the 6100/60AV's specifications for . This and the Quadra 630 were positioned for users who were not ready to move to PowerPC. Hardware The 660AV uses the pizza box form factor of the earlier Centris 610. The 660AV has a full Motorola 68040 instead of the 610's FPU-less 68LC040. Like the 840AV, the 660AV features video input/output capability and an onboard AT&T 3210 digital signal processor (here clocked at 55 MHz) to make the video handling less of a burden on the CPU. The 660AV is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
