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IBM P75
The IBM PS/2 portables are Micro Channel architecture-based, portable PS/2 computers released by IBM in 1989. PS/2 P70 The P70 model was released in Japan as PS/55 5545-T with the same specs, but with different keyboard layout. PS/2 P75 The P75 was a released in 1990 upgraded version of P70 model, and is noted as being the first portable computer using a 486 CPU to be available for sale in the United States. It had a briefcase-shaped design and ran off A/C power only, as was common with high performance portable computers at the time. It featured an Intel 80486 DX-33 CPU, and an internal 10-inch flat gas plasma display at 640x480 resolution with 16 shades of grey. The computer had relatively high performance specifications at the time it was released and could be used as a portable server. The cost reflected this performance; the IBM P75 retailed at US$15,990 for the base configuration, to over $18,500 or more depending on options. Two versions of the P75 were sold, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro Channel Architecture
Micro Channel architecture, or the Micro Channel bus, is a proprietary hardware, proprietary 16-bit computing, 16- or 32-bit computing, 32-bit parallel communication, parallel computer bus (computing), bus publicly introduced by IBM in 1987 which was used on IBM PS/2, PS/2 and other computers until the mid-1990s. Its name is commonly abbreviated as "MCA", although not by IBM. In IBM products, it superseded the Industry Standard Architecture, ISA bus and was itself subsequently superseded by the Peripheral Component Interconnect, PCI bus architecture. Background The development of Micro Channel was driven by both technical and business pressures. Technology The IBM AT bus, which later became known as the Industry Standard Architecture (ISA) bus, had a number of technical design limitations, including: * A slow bus speed. * A limited number of interrupts, fixed in hardware. * A limited number of I/O device addresses, also fixed in hardware. * Hardwired and complex configur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Graphics Adapter
The Color Graphics Adapter (CGA), originally also called the ''Color/Graphics Adapter'' or ''IBM Color/Graphics Monitor Adapter'', introduced in 1981, was IBM's first color graphics card for the IBM PC and established a De facto standard, de facto computer display standard. Hardware design The original IBM CGA graphics card was built around the Motorola 6845 display controller, came with 16 kilobytes of video memory built in, and featured several graphics and text modes. The highest display resolution of any mode was 640 × 200, and the highest color depth supported was 4-bit (16 colors). The CGA card could be connected either to a direct-drive CRT monitor using a 4-bit digital (Transistor-transistor logic, TTL) RGB(I), RGBI interface, such as the IBM 5153 color display, or to an NTSC-compatible television or composite video computer monitor, monitor via an RCA connector. The RCA connector provided only baseband video, so to connect the CGA card to a television set w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CMOS
Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss ", , ) is a type of MOSFET, metal–oxide–semiconductor field-effect transistor (MOSFET) semiconductor device fabrication, fabrication process that uses complementary and symmetrical pairs of p-type semiconductor, p-type and n-type semiconductor, n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuit (IC) chips, including microprocessors, microcontrollers, memory chips (including Nonvolatile BIOS memory, CMOS BIOS), and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors (CMOS sensors), data conversion, data converters, RF circuits (RF CMOS), and highly integrated transceivers for many types of communication. In 1948, Bardeen and Brattain patented an insulated-gate transistor (IGFET) with an inversion layer. Bardeen's concept forms the basis of CMOS technology today. The CMOS process was presented by Fairchild Semico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Supply Unit (computer)
A power supply unit (PSU) converts Mains electricity, mains AC to low-voltage regulated DC power for the internal components of a desktop computer. Modern personal computers universally use switched-mode power supply, switched-mode power supplies. Some Power supply, power supplies have a manual switch for selecting input voltage, while others automatically adapt to the main voltage. Most modern desktop personal computer power supplies conform to the ATX, ATX specification, which includes form factor and voltage tolerances. While an ATX power supply is connected to the mains supply, it always provides a 5-volt standby (5VSB) power so that the standby functions on the computer and certain peripherals are powered. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC voltages are in spec, so that the computer is able to safely power up and boot. The most recent ATX PSU standard is version 3.0 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 60320
IEC 60320, entitled "Appliance couplers for household and similar general purposes", is a set of standards published by the International Electrotechnical Commission (IEC) that defines non-locking appliance couplers for connecting power supply cords to electrical appliances. These couplers are intended for use with devices operating at voltages up to 250 Volt, V (Alternating current, AC) and currents up to 16 Ampere, A. The standard specifies various types of connectors, differentiated by shape and size, to accommodate different combinations of current ratings, temperature tolerances, and Earthing system, earthing requirements. Unlike IEC 60309 connectors, IEC 60320 couplers are not keyed or color-coded to indicate voltage; it is the responsibility of the user to ensure that the appliance's voltage rating is compatible with the local mains supply. The standard uses the term ''coupler'' to refer collectively to both the appliance inlets and outlets, as well as the connectors on po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VGA Connector
The Video Graphics Array (VGA) connector is a standard connector used for computer video output. Originating with the 1987 IBM PS/2 and its VGA graphics system, the 15-pin connector went on to become ubiquitous on PCs, as well as many monitors, projectors and HD television sets. Other connectors have been used to carry VGA-compatible signals, such as mini-VGA or BNC, but "''VGA connector''" typically refers to this design. Devices continue to be manufactured with VGA connectors, although newer digital interfaces such as DVI, HDMI and DisplayPort are increasingly displacing VGA, and many modern computers and other devices do not include it. Physical design The VGA connector is a three-row, 15-pin D-subminiature connector referred to variously as DE-15, HD-15 or commonly DB-15(HD). DE-15 is the accurate nomenclature under the proprietary D-sub specifications: an "E" size D-sub connector, with 15 pins in three rows. Predecessor and early variant The standard 15-pin VGA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PS/2 Port
The PS/2 port is a 6-pin mini-DIN connector used for connecting Computer keyboard, keyboards and computer mouse, mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987. The PS/2 mouse connector generally replaced the older DE-9 connector, DE-9 RS-232 "serial mouse" connector, while the PS/2 keyboard connector replaced the larger 5-pin/180° DIN connector used in the IBM PC/AT design. The PS/2 keyboard port is electrically and logically identical to the IBM AT keyboard port, differing only in the type of electrical connector used. The PS/2 platform introduced a second port with the same design as the keyboard port for use to connect a mouse; thus the PS/2-style keyboard and mouse interfaces are electrically similar and employ the same communication protocol. However, unlike the otherwise similar Apple Desktop Bus connector used by Apple, a given system's keyboard and mouse port may n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Port
A serial port is a serial communication Interface (computing), 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 communication, parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, computer terminal, terminals, various peripherals, and directly between computers. While interfaces such as Ethernet, FireWire, and USB also send data as a serial Stream (computing), stream, the term ''serial port'' usually denotes Computer hardware, 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 sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Port
In computing, a parallel port is a type of interface found on early computers ( personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once (parallel communication), as opposed to serial communication, in which bits are sent one at a time. To do this, parallel ports require multiple data lines in their cables and port connectors and tend to be larger than contemporary serial ports, which only require one data line. There are many types of parallel ports, but the term has become most closely associated with the printer port or Centronics port found on most personal computers from the 1970s through the 2000s. It was an industry ''de facto'' standard for many years, and was finally standardized as IEEE 1284 in the late 1990s, which defined the Enhanced Parallel Port (EPP) and Extended Capability Port (ECP) bi-directional versions. Today, the parallel port interface is virtually non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanosecond
A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, of a second, or seconds. The term combines the SI prefix ''nano-'' indicating a 1 billionth submultiple of an SI unit (e.g. nanogram, nanometre, etc.) and ''second'', the primary unit of time in the SI. A nanosecond is to one second, as one second is to approximately 31.69 years. A nanosecond is equal to 1000 picoseconds or microsecond. Time units ranging between 10 and 10 seconds are typically expressed as tens or hundreds of nanoseconds. Time units of this granularity are commonly found in telecommunications, pulsed lasers, and related aspects of electronics. Common measurements * 0.001 nanoseconds – one picosecond * 0.96 nanoseconds – 100 Gigabit Ethernet Interpacket gap * 96 nanoseconds – Gigabit Ethernet Interpacket gap * 1.0 nanosecond – cycle time of an electromagnetic wave with a frequency of 1 GHz (). * 1.0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIMM
A SIMM (single in-line memory module) is a type of memory module used in computers from the early 1980s to the early 2000s. It is a printed circuit board upon which multiple random-access memory Integrated circuit chips are attached to one or both sides. 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 1983 by James E. ClaytonClayton, James E. (1983)Low-cost, high-density memory packaging: A 64K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and Magnetic tape data storage, magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. In today's technology, random-access memory takes the form of integrated circuit (IC) chips with MOSFET, MOS (metal–oxide–semiconductor) Memory cell (computing), memory cells. RAM is normally associated with Volatile memory, volatile types of memory where s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
