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Apple II Accelerators
Apple II accelerators are computer hardware devices which enable an Apple II computer to operate faster than their intended clock rate. 8-bit accelerators Number Nine Apple Booster – ''Number Nine Computer Corporation (Number Nine Visual Technology)'' * Platform: Apple II, Apple II Plus * Form Factor: 50-pin slot card * Speed: 3.58 MHz * Cache: 64 KB onboard RAM * DMA compatible: No * Upgradeable: No Number Nine Apple Booster (1982) was one of the first accelerators for the Apple II series of computers. This card is the original version of Saturn's Accelerator II (thus the Accelerator II PCB shares both Saturn Systems' and NNCC's logos.) At $598, the Saturn was much cheaper than the NNCC, but little information about the board is available today. SpeedDemon – ''Microcomputer Technologies (M-c-T)'' * Platform: Apple II, Apple II Plus, Apple IIe * Form Factor: 50-pin slot card * Speed: 3.58 MHz * Cache: 4 KB cache * DMA compatible: No * Upgradeable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Hardware
Computer hardware includes the physical parts of a computer, such as the central processing unit (CPU), random-access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a Computer monitor, monitor, Computer mouse, mouse, Computer keyboard, keyboard, and Computer speakers, speakers. By contrast, software is a set of written instructions that can be stored and run by hardware. Hardware derived its name from the fact it is ''Hardness, hard'' or rigid with respect to changes, whereas software is ''soft'' because it is easy to change. Hardware is typically directed by the software to execute any command or Instruction (computing), instruction. A combination of hardware and software forms a usable computing system, although Digital electronics, other systems exist with only hardware. History Early computing devices were more complicated than the ancient abacus date to the seventeenth century. French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esc Key
On computer keyboards, the Esc key (named ''Escape key'' in the international standard series ISO/IEC 9995) is a key used to generate the escape character (which can be represented as ASCII code 27 in decimal, Unicode U+001B, or ). The escape character, when sent from the keyboard to a computer, often is interpreted by software as "stop", "cancel" or "exit", and when sent from the computer to an external device (including many printers since the 1980s, computer terminals and Linux consoles, for example) marks the beginning of an escape sequence to specify operating modes or characteristics generally. It is now generally placed at the top left corner of the keyboard, a convention dating at least to the original IBM PC keyboard, though the key itself originated decades earlier with teletypewriters. Symbol The keyboard symbol for the ESC key (which may be used when the usual Latin lettering is not preferred for labelling the key) is standardized in ISO/IEC 9995-7 as symbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Random-access Memory
Static random-access memory (static RAM or SRAM) is a type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed. The ''static'' qualifier differentiates SRAM from ''dynamic'' random-access memory (DRAM): * SRAM will hold its data permanently in the presence of power, while data in DRAM decays in seconds and thus must be periodically refreshed. * SRAM is faster than DRAM but it is more expensive in terms of silicon area and cost. * Typically, SRAM is used for the cache and internal registers of a CPU while DRAM is used for a computer's main memory. History Semiconductor bipolar SRAM was invented in 1963 by Robert Norman at Fairchild Semiconductor. Metal–oxide–semiconductor SRAM (MOS-SRAM) was invented in 1964 by John Schmidt at Fairchild Semiconductor. The first device was a 64-bit MOS p-channel SRAM. SRAM was the main driver behind any new CMOS-based technology fab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple IIc Plus
The Apple IIc Plus is the sixth and final model in the Apple II series of personal computers, produced by Apple Computer. The "''Plus''" in the name was a reference to the additional features it offered over the original portable Apple IIc, such as greater storage capacity (a built-in 3.5-inch floppy drive replacing the classic 5.25-inch drive), increased processing speed, and a general standardization of the system components. In a notable change of direction, the Apple IIc Plus, for the most part, did not introduce new technology or any further evolutionary contributions to the Apple II series, instead merely integrating existing peripherals into the original Apple IIc design. The development of the 8-bit machine was criticized by users more interested in the significantly more advanced 16-bit Apple IIGS. History By 1988 the Laser 128 series of Apple II clones was popular enough that it had, '' inCider'' wrote, "won a place in the Apple market, and irritated Apple in the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-maskable Interrupt
In computing, a non-maskable interrupt (NMI) is a hardware interrupt that standard interrupt-masking techniques in the system cannot ignore. It typically occurs to signal attention for non-recoverable hardware errors. Some NMIs may be masked, but only by using proprietary methods specific to the particular NMI. With regard to SPARC, the non-maskable interrupt (NMI), despite having the highest priority among interrupts, can be prevented from occurring through the use of an interrupt mask. An NMI is often used when response time is critical or when an interrupt should never be disabled during normal system operation. Such uses include reporting non-recoverable hardware errors, system debugging and profiling, and handling of special cases like system resets. Modern computer architectures typically use NMIs to handle non-recoverable errors which need immediate attention. Therefore, such interrupts should not be masked in the normal operation of the system. These errors include non-r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt Request
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card, key presses, or mouse movements. Interrupt lines are often identified by an index with the format of ''IRQ'' followed by a number. For example, on the Intel 8259 family of programmable interrupt controllers (PICs) there are eight interrupt inputs commonly referred to as ''IRQ0'' through ''IRQ7''. In x86 based computer systems that use two of these PICs, the combined set of lines are referred to as ''IRQ0'' through ''IRQ15''. Technically these lines are named ''IR0'' through ''IR7'', and the lines on the ISA bus to which they were historically attached are named ''IRQ0'' through ''IRQ15'' (although historically as the number of hardware devices increased, the total possible number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Memory Access
Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system computer memory, 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 some multi-core processors. Computers that h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple IIc
The Apple IIc is a personal computer introduced by Apple Inc. shortly after the launch of the Macintosh 128K, original Macintosh in 1984. It is essentially a compact and portable version of the Apple IIe. The IIc has a built-in floppy disk drive and a keyboard, and was often sold with its matching monitor. The ''c'' in the name stands for ''compact'', referring to the fact it is a complete Apple II setup in a smaller notebook-sized housing. The computer is compatible with a wide range of Apple II software and peripherals. The Apple IIc has rear peripheral expansion ports integrated onto the main logic board instead of the expansion slots and direct motherboard access of earlier Apple II models. Apple intended the Apple IIc to require less technical expertise to use. The Apple IIc weighs . It was succeeded by the Apple IIc Plus in 1988. History The Apple IIc was released on April 24, 1984, during an Apple-held event called ''Apple II Forever''. With that motto, Apple proclaimed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual In-line Package
In microelectronics, a dual in-line package (DIP or DIL) is an Semiconductor package, electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole technology, 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 Semiconductor, 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 refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System In Package
A system in a package (SiP) or system-in-package is a number of integrated circuits (ICs) enclosed in one chip carrier package or encompassing an IC package substrate that may include passive components and perform the functions of an entire system. The ICs may be stacked using package on package, placed side by side, and/or embedded in the substrate. The SiP performs all or most of the functions of an electronic system, and is typically used when Integrated circuit design, designing components for mobile phone, mobile phones, Portable media player, digital music players, etc. die (integrated circuit), Dies containing integrated circuits may be stacked vertically on the package substrate. They are internally connected by fine wires that are bonded to the package substrate. Alternatively, with a flip chip technology, solder bumps are used to join stacked chips together and to the package substrate, or even both techniques can be used in a single package. SiPs are like system on a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microprocessor
A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit (CPU). The IC is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, Clock signal, clock-driven, Processor register, register-based, digital integrated circuit that accepts binary code, binary data as input, processes it according to instruction (computing), instructions stored in its computer memory, memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential logic, sequential digital logic, and operate on numbers and symbols represented in the binary number system. The integration of a whole CPU on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus slot) on a computer's motherboard (see also backplane) to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most (or all) of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard. Expansion cards allow the capabilities and interfaces of a computer system to be extended or supplemented in a way appropriate to the tasks it will perform. For example, a high-speed multi-channel data acquisition system would be of no use in a personal computer used for bookkeeping, but might be a key part of a system used for in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
