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Macintosh Classic II
The Macintosh Classic II (also sold as the Performa 200) is a personal computer designed, manufactured and sold by Apple Computer, Inc. from October 1991 to September 1993. Like the Macintosh SE/30, the Classic II was powered by a 16 MHz Motorola 68030 CPU and 40 or 80 MB hard disk, but in contrast to the SE/30, it was limited by a 16-bit data bus (the SE/30 had a 32-bit data bus) and a 10 MB memory ceiling. The slower data bus resulted in the Classic II being 30% slower than the SE/30. While the Classic II shares a case with the earlier Classic, architecturally it has more similarities to the Macintosh LC. The use of custom ICs, identical to those used in the LC, enabled the Classic II to have a lower component count than older Macs. Unlike the LC and the SE/30 before it, the Classic II does not have an internal Processor Direct Slot, making it the second slotless desktop Macintosh after the Classic. The Classic II was one of the three machines Apple repackaged as a Macinto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finder (software)
The Finder is the default file manager and graphical user interface shell used on all Macintosh operating systems. Described in its "About" window as "The Macintosh Desktop Experience", it is responsible for the launching of other applications, and for the overall user management of files, disks, and network volumes. It was introduced with the first Macintosh computer, and also exists as part of GS/OS on the Apple IIGS. It was rewritten completely with the release of Mac OS X in 2001. In a tradition dating back to the Classic Mac OS of the 1980s and 1990s, the Finder icon is the smiling screen of a computer, known as the Happy Mac logo. Features The Finder uses a view of the file system that is rendered using a desktop metaphor; that is, the files and folders are represented as appropriate icons. It uses a similar interface to Apple's Safari browser, where the user can click on a folder to move to it and move between locations using "back" and "forward" arrow buttons. Lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DB-25
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 of connectors and fasteners, 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) Jackscrew#In_electronic_connectors, jackscrews that accept screws on the cable end connector cover that are used for locking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers. While interfaces such as Ethernet, FireWire, and USB also send data as a serial stream, the term ''serial port'' usually denotes hardware compliant with RS-232 or a related standard, such as RS-485 or RS-422. Modern consumer personal computers (PCs) have largely replaced serial ports with higher-speed standards, primarily USB. However, serial ports are still frequently used in applications demanding simple, low-speed interfaces, such as industrial automation systems, scientific instruments, point of sale systems and some industrial and consumer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS-422
RS-422, also known as TIA/EIA-422, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. It was meant to be the foundation of a suite of standards that would replace the older RS-232C standard with standards that offered much higher speed, better immunity from noise, and longer cable lengths. RS-422 systems can transmit data at rates as high as 10 Mbit/s, or may be sent on cables as long as at lower rates. It is closely related to RS-423, which uses the same signaling systems but on a different wiring arrangement. RS-422 specifies differential signaling, with every data line paired with a dedicated return line. It is the voltage difference between these two lines that define the mark and space, rather than, as in RS-232, the difference in voltage between a data line and a local ground. As the ground voltage can differ at either end of the cable, this required RS-232 to use signals with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mini-DIN
The mini-DIN connectors are a family of multi-pin electrical connectors used in a variety of applications. Mini-DIN is similar to the larger, older DIN connector. Design Mini-DIN connectors are in diameter and come in seven patterns, with the number of pins from three to nine. Each pattern is keyed in such a way that a plug with one pattern cannot be mated with any socket of another pattern. They are each drastically different from the other, with no simultaneously and directly overlapping similarities in (1) pin arrangement, (2) square key size and position, (3) circular shielding metal skirt notches and metallic additions: in this they differ from the nonstandard mini-DIN connectors which may have directly overlapping characteristics to each other or to the standard mini-DIN connectors. Notable usage Some notable examples of standard mini-DIN connectors include: * Mini-DIN-3 connectors were used in early implementations of Apple LocalTalk. * Mini-DIN-4 connectors ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Desktop Bus
Apple Desktop Bus (ADB) is a proprietary bit-serial peripheral bus connecting low-speed devices to computers. It was introduced on the Apple IIGS in 1986 as a way to support low-cost devices like keyboards and mice, allowing them to be connected together in a daisy chain without the need for hubs or other devices. Apple Device Bus was quickly introduced on later Macintosh models, on later models of NeXT computers, and saw some other third-party use as well. Like the similar PS/2 connector used in many PC-compatibles at the time, Apple Desktop Bus was rapidly replaced by USB as that system became popular in the late 1990s; the last external Apple Desktop Bus port on an Apple product was in 1999, though it remained as an internal-only bus on some Mac models into the 2000s. History AppleBus Early during the creation of the Macintosh computer, the engineering team had selected the fairly sophisticated Zilog 8530 to supply serial communications. This was initially done to allow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling Rate
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or space; this definition differs from the Sample (statistics), usage in statistics, which refers to a set of such values. A sampler is a subsystem or operation that extracts samples from a continuous signal. A theoretical ideal sampler produces samples equivalent to the instantaneous value of the continuous signal at the desired points. The original signal can be reconstructed from a sequence of samples, up to the Nyquist limit, by passing the sequence of samples through a type of low-pass filter called a reconstruction filter. Theory Functions of space, time, or any other dimension can be sampled, and similarly in two or more dimensions. For functions that vary with time, let ''S''(''t'') be a continuous function (or "signal") to be samp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''sensel'' is sometimes used), while in yet other contexts (like MRI) it may refer to a set of component intensities for a spatial position. Etymology The w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIMM
A SIMM (single in-line memory module) is a type of memory module containing random-access memory used in computers from the early 1980s to the early 2000s. It differs from a dual in-line memory module (DIMM), the most predominant form of memory module since the late 1990s, in that the contacts on a SIMM are redundant on both sides of the module. SIMMs were standardised under the JEDEC JESD-21C standard. Most early PC motherboards (8088-based PCs, XTs, and early ATs) used socketed DIP chips for DRAM. As computer memory capacities grew, memory modules were used to save motherboard space and ease memory expansion. Instead of plugging in eight or nine single DIP chips, only one additional memory module was needed to increase the memory of the computer. History SIMMs were invented in 1982 by James J. Parker at Zenith Microcircuits and the first Zenith Microcircuits customer was Wang Laboratories. Wang Laboratories tried to patent it and were granted a patent in April 1987. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola 68882
The Motorola 68881 and Motorola 68882 are floating-point units (FPUs) used in some computer systems in conjunction with Motorola's 32-bit 68020 or 68030 microprocessors. These coprocessors are external chips, designed before floating point math became standard on CPUs. The Motorola 68881 was introduced in 1984. The 68882 is a higher performance version produced later. Overview The 68020 and 68030 CPUs were designed with the separate 68881 chip in mind. Their instruction sets reserved the "F-line" instructions – that is, all opcodes beginning with the hexadecimal digit "F" could either be forwarded to an external coprocessor or be used as "traps" which would throw an exception, handing control to the computer's operating system. If an FPU is not present in the system, the OS would then either call an FPU emulator to execute the instruction's equivalent using 68020 integer-based software code, return an error to the program, terminate the program, or crash and require a reboot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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