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115-521: The P70 model was released in Japan as PS/55 5545-T with the same specs, but with different keyboard layout. 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

230-520: A 3 μm process . The Hitachi HM6147 chip was able to match the performance (55/70   ns access) of the Intel 2147 HMOS chip, while the HM6147 also consumed significantly less power (15   mA ) than the 2147 (110   mA). With comparable performance and much less power consumption, the twin-well CMOS process eventually overtook NMOS as the most common semiconductor manufacturing process for computers in

345-419: A 350   nm CMOS process, while Hitachi and NEC commercialized 250   nm CMOS. Hitachi introduced a 160   nm CMOS process in 1995, then Mitsubishi introduced 150   nm CMOS in 1996, and then Samsung Electronics introduced 140   nm in 1999. In 2000, Gurtej Singh Sandhu and Trung T. Doan at Micron Technology invented atomic layer deposition High-κ dielectric films , leading to

460-532: A UNIX operating system for PS/2 models with Intel 386 or later processors. IBM's initial PS/2 computers were popular with target market corporate buyers, and by September 1988, IBM reported that it had sold 3 million PS/2 machines in the past 18 months. However, the PS/2 was unsuccessful in the consumer market since IBM failed to establish a link in the consumer's mind between the PS/2 MicroChannel architecture and

575-457: A 160 MB SCSI hard disk drive (model 8573-161) or a 400 MB SCSI (model 8573-401), with the onboard SCSI controller being capable of handling drives up to 1GB. The IBM P75 supports up to 16 megabytes of Random-access memory through 4 SIMM slots on the motherboard, each of which can accept a 2 MB or 4 MB 70 nanosecond SIMM. The SIMM must be manufactured by IBM for the computer to accept them – non-IBM SIMMs or generic SIMMs that do not utilise

690-466: A 20   μm semiconductor manufacturing process before gradually scaling to a 10 μm process over the next several years. CMOS technology was initially overlooked by the American semiconductor industry in favour of NMOS, which was more powerful at the time. However, CMOS was quickly adopted and further advanced by Japanese semiconductor manufacturers due to its low power consumption, leading to

805-545: A CMOS IC chip for a Seiko quartz watch in 1969, and began mass-production with the launch of the Seiko Analog Quartz 38SQW watch in 1971. The first mass-produced CMOS consumer electronic product was the Hamilton Pulsar "Wrist Computer" digital watch, released in 1970. Due to low power consumption, CMOS logic has been widely used for calculators and watches since the 1970s. The earliest microprocessors in

920-460: A CMOS circuit. This example shows a NAND logic device drawn as a physical representation as it would be manufactured. The physical layout perspective is a "bird's eye view" of a stack of layers. The circuit is constructed on a P-type substrate. The polysilicon , diffusion, and n-well are referred to as "base layers" and are actually inserted into trenches of the P-type substrate. (See steps 1 to 6 in

1035-482: A CMOS device: P = 0.5 C V 2 f {\displaystyle P=0.5CV^{2}f} . Since most gates do not operate/switch at every clock cycle , they are often accompanied by a factor α {\displaystyle \alpha } , called the activity factor. Now, the dynamic power dissipation may be re-written as P = α C V 2 f {\displaystyle P=\alpha CV^{2}f} . A clock in

1150-443: A PMOS transistor creates low resistance between its source and drain contacts when a low gate voltage is applied and high resistance when a high gate voltage is applied. On the other hand, the composition of an NMOS transistor creates high resistance between source and drain when a low gate voltage is applied and low resistance when a high gate voltage is applied. CMOS accomplishes current reduction by complementing every nMOSFET with

1265-401: A brief spike in power consumption and becomes a serious issue at high frequencies. The adjacent image shows what happens when an input is connected to both a PMOS transistor (top of diagram) and an NMOS transistor (bottom of diagram). Vdd is some positive voltage connected to a power supply and Vss is ground. A is the input and Q is the output. When the voltage of A is low (i.e. close to Vss),

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1380-456: A close relative of CMOS. He invented complementary flip-flop and inverter circuits, but did no work in a more complex complementary logic. He was the first person able to put p-channel and n-channel TFTs in a circuit on the same substrate. Three years earlier, John T. Wallmark and Sanford M. Marcus published a variety of complex logic functions implemented as integrated circuits using JFETs , including complementary memory circuits. Frank Wanlass

1495-507: A complex called the Power Platform. The PS/2 Models 90 (IBM 8590/9590) and 95 (IBM 8595/9595/9595A) used Processor Complex daughterboards holding the CPU , memory controller, MCA interface, and other system components. The available Processor Complex options ranged from the 20 MHz Intel 486 to the 90 MHz Pentium and were fully interchangeable. The IBM PC Server 500 , which has

1610-574: A full AT-class machine and support up to 4 MB of RAM. Later ISA PS/2 models comprised the Model 30 286 (a Model 30 with an Intel 286 CPU), Model 35 (IBM 8535) and Model 40 (IBM 8540) with Intel 386SX or IBM 386SLC processors. The higher-numbered models (above 50) were equipped with the Micro Channel bus and mostly ESDI or SCSI hard drives (models 60-041 and 80-041 had MFM hard drives). PS/2 Models 50 (IBM 8550) and 60 (IBM 8560) used

1725-458: A high density of logic functions on a chip. It was primarily for this reason that CMOS became the most widely used technology to be implemented in VLSI chips. The phrase "metal–oxide–semiconductor" is a reference to the physical structure of MOS field-effect transistors , having a metal gate electrode placed on top of an oxide insulator, which in turn is on top of a semiconductor material . Aluminium

1840-499: A high of 10,000 employees in Boca Raton before the PS/2 came out, only seven years later, IBM had $ 600 million in unsold inventory and was laying off staff by the thousands. After the failure of the PS/2 line to establish a new standard, IBM was forced to revert to building ISA PCs—following the industry it had once led—with the low-end PS/1 line and later with the more compatible Aptiva and PS/ValuePoint lines. Still,

1955-454: A link in the consumer's mind between the PS/2 MicroChannel architecture and the immature OS/2 1.x operating system; the more capable OS/2 version 2.0 was not released until 1992. The firm suffered massive financial losses for the remainder of the 1980s, forfeiting its previously unquestioned position as the industry leader, and eventually lost its status as the largest manufacturer of personal computers, first to Compaq and then to Dell . From

2070-484: A more finely graduated range (powers of 2, instead of powers of 4). Many PS/2 models also used proprietary IBM SIMMs and could not be fitted with commonly available types. However industry standard SIMMs could be modified to work in PS/2 machines if the SIMM-presence and SIMM-type detection bridges, or associated contacts, were correctly rewired. At launch, the PS/2 family comprised the Model 30 , 50 , 60 and 80 ;

2185-533: A motherboard identical to the 9595A, also uses Processor Complexes. Other later Micro Channel PS/2 models included the Model 65SX with a 16 MHz 386SX; various Model 53 (IBM 9553), 56 (IBM 8556) and 57 (IBM 8557) variants with 386SX, 386SLC or 486SLC2 processors; the Models 76 and 77 (IBM 9576/9577) with 486SX or 486DX2 processors respectively; and the 486-based Model 85 (IBM 9585). The IBM PS/2E (IBM 9533)

2300-431: A pMOSFET and connecting both gates and both drains together. A high voltage on the gates will cause the nMOSFET to conduct and the pMOSFET not to conduct, while a low voltage on the gates causes the reverse. This arrangement greatly reduces power consumption and heat generation. However, during the switching time, both pMOS and nMOS MOSFETs conduct briefly as the gate voltage transitions from one state to another. This induces

2415-631: A portable. It features an Intel i486-DX 33 CPU that is housed on a processor complex card separate from the motherboard. The computer uses IBM's Micro Channel architecture (MCA) bus and has 4 internal bus slots: one 32-bit AVE, one 32-bit MME, and two 16-bit short slots. The internal gas plasma display of the IBM P75 is XGA /VGA, EGA , MCGA , CGA compatible, and operates at a maximum 640×480 in 16 shades of grey in VGA mode. The IBM P75 can drive its internal monitor and an external monitor simultaneously. When driving

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2530-415: A printer, could now function as a high-speed data transfer interface. This allowed the use of new hardware such as parallel port scanners , CD-ROM drives, and also enhanced the capabilities of printers by allowing them to communicate with the host PC and send back signals instead of simply being a passive output device. Most of the initial range of PS/2 models were equipped with a new frame buffer known as

2645-458: A production life span that took them into the late 1990s, within a few years of IBM selling off the division. CMOS Complementary metal–oxide–semiconductor ( CMOS , pronounced "sea-moss ", / s iː m ɑː s / , /- ɒ s / ) is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology

2760-512: A rectangular piece of silicon of often between 10 and 400 mm . CMOS always uses all enhancement-mode MOSFETs (in other words, a zero gate-to-source voltage turns the transistor off). CMOS circuits are constructed in such a way that all P-type metal–oxide–semiconductor (PMOS) transistors must have either an input from the voltage source or from another PMOS transistor. Similarly, all NMOS transistors must have either an input from ground or from another NMOS transistor. The composition of

2875-553: A result of this a 720 KB floppy could be formatted to 1440 KB in a PS/2, but the resulting floppy would only be readable by a PS/2 machine. PS/2s primarily used Mitsubishi floppy drives and did not use a separate Molex power connector; the data cable also contained the power supply lines. As the hardware aged the drives often malfunctioned due to bad quality capacitors . The PS/2 used several different types of internal hard drives. Early models used MFM or ESDI drives. Some desktop models used combo power/data cables similar to

2990-413: A small period of time in which current will find a path directly from V DD to ground, hence creating a short-circuit current , sometimes called a crowbar current. Short-circuit power dissipation increases with the rise and fall time of the transistors. This form of power consumption became significant in the 1990s as wires on chip became narrower and the long wires became more resistive. CMOS gates at

3105-419: A somewhat standardized capacity of 2880 KB. The PS/2 floppy drives lacked a capacity detector. 1440 KB floppies had a hole so that drives could distinguish them from 720 KB floppies, preventing users from formatting the smaller capacity disks to the higher capacity (doing so would work, but with a higher tendency of data loss). Clone manufacturers implemented the hole detection, but IBM did not. As

3220-425: A system has an activity factor α=1, since it rises and falls every cycle. Most data has an activity factor of 0.1. If correct load capacitance is estimated on a node together with its activity factor, the dynamic power dissipation at that node can be calculated effectively. Since there is a finite rise/fall time for both pMOS and nMOS, during transition, for example, from off to on, both the transistors will be on for

3335-443: A trade-off for devices to become slower. To speed up designs, manufacturers have switched to constructions that have lower voltage thresholds but because of this a modern NMOS transistor with a V th of 200 mV has a significant subthreshold leakage current. Designs (e.g. desktop processors) which include vast numbers of circuits which are not actively switching still consume power because of this leakage current. Leakage power

3450-549: A version of BSD UNIX for the ROMP that was only available to select colleges and universities. The RISC Adapter Card contained the ROMP-C microprocessor (an enhanced version of the ROMP that first appeared in the IBM RT PC workstations), a memory management unit (the ROMP had virtual memory ), a floating-point coprocessor , and up to 8   MB of memory for use by the ROMP. The 6152

3565-523: A year, and the largest such account review in the history of business. Overall, the PS/2 line was largely unsuccessful with the consumer market, even though the PC-based Models 30 and 25 were an attempt to address that. With what was widely seen as a technically competent but cynical attempt to gain undisputed control of the market, IBM unleashed an industry backlash, which went on to standardize VESA, EISA and PCI. In large part, IBM failed to establish

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3680-474: Is a feature of the PCI-X bus format. Bus mastering capability, bus arbitration, and a primitive form of plug-and-play management of hardware were all benefits of MCA. Gilbert Held in his 2000 book Server Management observes: "MCA used an early (and user-hostile) version of what we know now as 'Plug-N′-Play', requiring a special setup disk for each machine and each card." MCA never gained wide acceptance outside of

3795-471: Is a significant portion of the total power consumed by such designs. Multi-threshold CMOS (MTCMOS), now available from foundries, is one approach to managing leakage power. With MTCMOS, high V th transistors are used when switching speed is not critical, while low V th transistors are used in speed sensitive paths. Further technology advances that use even thinner gate dielectrics have an additional leakage component because of current tunnelling through

3910-405: Is connected to V SS and an N-type n-well tap is connected to V DD to prevent latchup . CMOS logic dissipates less power than NMOS logic circuits because CMOS dissipates power only when switching ("dynamic power"). On a typical ASIC in a modern 90 nanometer process, switching the output might take 120 picoseconds, and happens once every ten nanoseconds. NMOS logic dissipates power whenever

4025-457: Is connected together in metal (illustrated in cyan coloring). Connections between metal and polysilicon or diffusion are made through contacts (illustrated as black squares). The physical layout example matches the NAND logic circuit given in the previous example. The N device is manufactured on a P-type substrate while the P device is manufactured in an N-type well (n-well). A P-type substrate "tap"

4140-652: Is fully compatible with OS/2 , AIX , MS-DOS , IBM PC DOS and Microsoft Windows . IBM Personal System The Personal System/2 or PS/2 is IBM 's second generation of personal computers . Released in 1987, it officially replaced the IBM PC , XT , AT , and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART (serial port), 1440 KB 3.5-inch floppy disk format, 72-pin SIMMs , PS/2 port , and VGA video standard , went on to become standards in

4255-478: Is maintained through an internal non-rechargeable 6V battery. Should the internal 6V battery run low, the computer may not POST successfully as the internal CMOS contents are corrupted. The reference diskette also includes basic diagnostic software. If the computer is booted without an operating system and/or hard disk, the P75 will boot into IBM Cassette BASIC . IBM did not ship with any additional operating system, but

4370-647: Is not true of the 95xx models (and some unlisted 85xx's), which are specialist workstation displays designed for use with the XGA-2 or Image Adapter/A cards, and whose fixed frequencies all exceed that of basic VGA – the lowest of their commonly available modes instead being 640 × 480 at 75 Hz, if not something much higher still. It is also worth noting that these were still merely dual- or "multiple-frequency" monitors, not variable-frequency (also known as multisync); in particular, despite running happily at 640 × 480 , 720 × 400 and 1024 × 768 , an (e.g.) 8514 cannot sync

4485-465: Is that both low-to-high and high-to-low output transitions are fast since the (PMOS) pull-up transistors have low resistance when switched on, unlike the load resistors in NMOS logic. In addition, the output signal swings the full voltage between the low and high rails. This strong, more nearly symmetric response also makes CMOS more resistant to noise. See Logical effort for a method of calculating delay in

4600-447: Is the duality that exists between its PMOS transistors and NMOS transistors. A CMOS circuit is created to allow a path always to exist from the output to either the power source or ground. To accomplish this, the set of all paths to the voltage source must be the complement of the set of all paths to ground. This can be easily accomplished by defining one in terms of the NOT of the other. Due to

4715-518: Is used for constructing integrated circuit (IC) chips, including microprocessors , microcontrollers , memory chips (including CMOS BIOS ), and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors ( CMOS sensors ), 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

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4830-456: Is very small compared to sub threshold and tunnelling currents, so these may be neglected during power calculations. If the ratios do not match, then there might be different currents of PMOS and NMOS; this may lead to imbalance and thus improper current causes the CMOS to heat up and dissipate power unnecessarily. Furthermore, recent studies have shown that leakage power reduces due to aging effects as

4945-590: The Intel 286 processor, the PS/2 Models 70 386 (IBM 8570) and 80 used the 386DX , while the mid-range PS/2 Model 55 SX (IBM 8555–081) and used the 16/32-bit 386SX processor. The Model 50 was revised to the Model 50 Z still with 10 MHz 80286 processor, but with memory run at zero wait state, and a switch to ESDI hard drives. Later Model 70 486 and 80 variants (B-xx) also used 25 MHz Intel 486 processors, in

5060-524: The Model 25 was launched a few months later. The PS/2 Models 25 and 30 (IBM 8525 and 8530, respectively) were the lowest-end models in the lineup and meant to replace the IBM PC and XT. Model 25s came with either an 8086 CPU running at 8 MHz, 512 KB of RAM, and 720 KB floppy disks, or 80286 CPU. The 8086s had ISA expansion slots and a built-in MCGA monitor, which could be either color or monochrome, while

5175-540: The PC Convertible . In addition, they could be had as an optional feature on the XT and AT. The PS/2 line used entirely 3.5" drives which assisted in their quick adoption by the industry, although the lack of 5.25" drive bays in the computers created problems later on in the 1990s as they could not accommodate internal CD-ROM drives. In addition, the lack of built-in 5.25" floppy drives meant that PS/2 users could not immediately run

5290-521: The Video Graphics Array , or VGA for short. This effectively replaced the previous EGA standard. VGA increased graphics memory to 256 KB and provided for resolutions of 640×480 with 16 colors, and 320 × 200 with 256 colors. VGA also provided a palette of 262,144 colors (as opposed to the EGA palette of 64 colors). The IBM 8514 and later XGA computer display standards were also introduced on

5405-431: The "presence detect" feature cannot be used unless modified. The stock configuration of RAM on IBM P75 is 8 MB. The IBM P75 featured numerous ports, including an external SCSI connector, a parallel port , a serial port , a PS/2 mouse port , an external 5.25" floppy disk port, and a VGA port . The ports are housed behind a door on the rear of the unit which allows for them to be hidden when not in use. The recess behind

5520-431: The 1970s. The Intel 5101 (1   kb SRAM ) CMOS memory chip (1974) had an access time of 800   ns , whereas the fastest NMOS chip at the time, the Intel 2147 (4   kb SRAM) HMOS memory chip (1976), had an access time of 55/70   ns. In 1978, a Hitachi research team led by Toshiaki Masuhara introduced the twin-well Hi-CMOS process, with its HM6147 (4   kb SRAM) memory chip, manufactured with

5635-485: The 1980s. In the 1980s, CMOS microprocessors overtook NMOS microprocessors. NASA 's Galileo spacecraft, sent to orbit Jupiter in 1989, used the RCA 1802 CMOS microprocessor due to low power consumption. Intel introduced a 1.5 μm process for CMOS semiconductor device fabrication in 1983. In the mid-1980s, Bijan Davari of IBM developed high-performance, low-voltage, deep sub-micron CMOS technology, which enabled

5750-580: The 80286 models came with VGA monitor and ISA expansion slots. A cut-down Model M keyboard with no numeric keypad was standard, with the normal keyboard being an extra-cost option. There was a very rare later model called the PS/2 Model 25-SX which sported either a 16 MHz or 20 MHz 386 CPU, up to 12 MB of memory, IDE hard drive, VGA Monitor and 16 bit ISA slots making it the highest available model 25 available denoted by model number 8525-L41. The Model 30 had either an 8086 or 286 CPU and sported

5865-462: The A or B inputs is low, one of the NMOS transistors will not conduct, one of the PMOS transistors will, and a conductive path will be established between the output and V dd (voltage source), bringing the output high. As the only configuration of the two inputs that results in a low output is when both are high, this circuit implements a NAND (NOT AND) logic gate. An advantage of CMOS over NMOS logic

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5980-456: The CMOS device. Clamp diodes are included in CMOS circuits to deal with these signals. Manufacturers' data sheets specify the maximum permitted current that may flow through the diodes. Besides digital applications, CMOS technology is also used in analog applications. For example, there are CMOS operational amplifier ICs available in the market. Transmission gates may be used as analog multiplexers instead of signal relays . CMOS technology

6095-451: The MOSFET pair is always off, the series combination draws significant power only momentarily during switching between on and off states. Consequently, CMOS devices do not produce as much waste heat as other forms of logic, like NMOS logic or transistor–transistor logic (TTL), which normally have some standing current even when not changing state. These characteristics allow CMOS to integrate

6210-450: The NMOS transistor's channel is in a high resistance state, disconnecting Vss from Q. The PMOS transistor's channel is in a low resistance state, connecting Vdd to Q. Q, therefore, registers Vdd. On the other hand, when the voltage of A is high (i.e. close to Vdd), the PMOS transistor is in a high resistance state, disconnecting Vdd from Q. The NMOS transistor is in a low resistance state, connecting Vss to Q. Now, Q registers Vss. In short,

6325-409: The P75 were sold, with the only difference between the two being hard drive capacity: The IBM P75 in its travelling configuration resembles a briefcase with a carrying handle - all components such as the screen, floppy disk drive and keyboard are stowed away behind the keyboard during transport. To use the computer, one places the computer on a desk and opens the latches at either side of the front of

6440-661: The PC/XT/AT. CBIOS was so compatible that it even included Cassette BASIC . While IBM did not publish the BIOS source code, it did promise to publish BIOS entry points . With certain models to the IBM PS/2 line, Micro Channel Architecture (MCA) was also introduced. MCA was conceptually similar to the channel architecture of the IBM System/360 mainframes. MCA was technically superior to ISA and allowed for higher-speed communications within

6555-416: The PMOS transistors (top half) will conduct, and a conductive path will be established between the output and V ss (ground), bringing the output low. If both of the A and B inputs are low, then neither of the NMOS transistors will conduct, while both of the PMOS transistors will conduct, establishing a conductive path between the output and V dd (voltage source), bringing the output high. If either of

6670-567: The PS/2 introduced a new software data area known as the Extended BIOS Data Area (EBDA). Its primary use was to add a new buffer area for the dedicated mouse port. This also required making a change to the "traditional" BIOS Data Area (BDA) which was then required to point to the base address of the EBDA. Another new PS/2 innovation was the introduction of bidirectional parallel ports which, in addition to their traditional use for connecting

6785-460: The PS/2 line in July 1995. IBM's PS/2 was designed to remain software compatible with their PC/AT/XT line of computers upon which the large PC clone market was built, but the hardware was quite different. PS/2 had two BIOSes : one named ABIOS (Advanced BIOS) which provided a new protected mode interface and was used by OS/2, and CBIOS (Compatible BIOS) which was included to be software compatible with

6900-483: The PS/2 line. Key monitors and their maximum resolutions: In truth, all XGA 1024 × 768 monitors are multimode, as XGA works as an add-on card to a built-in VGA and transparently passes the VGA signal through when not operating in a high-resolution mode. All of the listed 85xx displays can therefore sync 640×480 at 60 Hz (or 720 × 400 at 70 Hz) in addition to any higher mode they may also be capable of. This however

7015-433: The PS/2 platform experienced some success in the corporate sector where the reliability, ease of maintenance and strong corporate support from IBM offset the rather daunting cost of the machines. Also, many people still lived with the motto " Nobody ever got fired for buying an IBM ". In the mid-range desktop market, the models 55SX and later 56SX were the leading sellers for almost their entire lifetimes. Later PS/2 models saw

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7130-454: The PS/2. When setting up the card with its disk, all choices for interrupts and other changes were accomplished automatically by the PC reading the old configuration from the floppy disk. This made necessary changes, then recorded the new configuration to the floppy disk. This meant that the user must keep that same floppy disk matched to that particular PC. For a small organization with a few PCs, this

7245-408: The addition of an extra key to the right of the left Shift key. PS/2 systems introduced a new specification for the keyboard and mouse interfaces, which are still in use today (though increasingly supplanted by USB devices) and are thus called "PS/2" interfaces. The PS/2 keyboard interface, inspired by Apple's ADB interface, was electronically identical to the long-established AT interface, but

7360-537: The basis of CMOS technology today. The CMOS process was presented by Fairchild Semiconductor 's Frank Wanlass and Chih-Tang Sah at the International Solid-State Circuits Conference in 1963. Wanlass later filed US patent 3,356,858 for CMOS circuitry and it was granted in 1967. RCA commercialized the technology with the trademark "COS-MOS" in the late 1960s, forcing other manufacturers to find another name, leading to "CMOS" becoming

7475-414: The best performance per watt each year have been CMOS static logic since 1976. As of 2019, planar CMOS technology is still the most common form of semiconductor device fabrication, but is gradually being replaced by non-planar FinFET technology, which is capable of manufacturing semiconductor nodes smaller than 20   nm . "CMOS" refers to both a particular style of digital circuitry design and

7590-574: The bottom-rung 8086-based Model 25 and 30, which had a cut-down version of VGA referred to as MCGA ; the 286 models came with VGA. This supported CGA graphics modes, VGA 320 × 200 256 color and 640 × 480 monochrome mode, but not EGA or color 640 × 480 . All of the new PS/2 graphics systems (whether MCGA, VGA, 8514, or later XGA) used a 15-pin D-sub connector for video out. This used analog RGB signals, rather than four or six digital color signals as on previous CGA and EGA monitors. The digital signals limited

7705-494: The broader PC market. The PS/2 line was created by IBM partly in an attempt to recapture control of the PC market by introducing the advanced yet proprietary Micro Channel architecture (MCA) on higher-end models. These models were in the strange position of being incompatible with the hardware standards previously established by IBM and adopted in the IBM PC compatible industry. Most major PC manufacturers balked at IBM's licensing terms for MCA-compatible hardware, particularly

7820-562: The cable connector was changed from the 5-pin DIN connector to the smaller 6-pin mini-DIN interface. The same connector and a similar synchronous serial interface was used for the PS/2 mouse port. The initial desktop Model 50 and Model 70 also featured a new cableless internal design, based on use of interposer circuit boards to link the internal drives to the planar (motherboard). Additionally, these machines could be largely disassembled and reassembled for service without tools. Additionally,

7935-545: The case, featured MCA and a 486SLC CPU. The 6152 Academic System was a workstation computer developed by IBM's Academic Information Systems (ACIS) division for the university market introduced in February 1988. The 6152 was based on the PS/2 Model 60, adding a RISC Adapter Card on the Micro Channel bus. This card was a co-processor that enabled the 6152 to run ROMP software compiled for IBM's Academic Operating System (AOS),

8050-417: The color gamut to a fixed 16- or 64-color palette with no room for expansion. In contrast, any color depth (bits per primary) can be encoded into the analog RGB signals so the color gamut can be increased arbitrarily by using wider (more bits per sample) DACs and a more sensitive monitor. The connector was also compatible with analog grayscale displays. Unlike earlier systems such as MDA and Hercules , this

8165-433: The computer to release the keyboard, which swings down. The keyboard can then be fully released from the main unit and height adjusted for comfort. The screen viewing angle can also be adjusted by pulling on tabs on either side of the screen. To access the floppy drive, one pushes on a raised square on the floppy drive disk cover to release it. The IBM P75 has similar specifications to an IBM model 90, but has been made into

8280-412: The concept of an inversion layer, forms the basis of CMOS technology today. A new type of MOSFET logic combining both the PMOS and NMOS processes was developed, called complementary MOS (CMOS), by Chih-Tang Sah and Frank Wanlass at Fairchild. In February 1963, they published the invention in a research paper . In both the research paper and the patent filed by Wanlass, the fabrication of CMOS devices

8395-430: The corresponding supply voltage, modelling an AND. When a path consists of two transistors in parallel, either one or both of the transistors must have low resistance to connect the supply voltage to the output, modelling an OR. Shown on the right is a circuit diagram of a NAND gate in CMOS logic. If both of the A and B inputs are high, then both the NMOS transistors (bottom half of the diagram) will conduct, neither of

8510-433: The development of a cost-effective 90 nm CMOS process. Toshiba and Sony developed a 65 nm CMOS process in 2002, and then TSMC initiated the development of 45 nm CMOS logic in 2004. The development of pitch double patterning by Gurtej Singh Sandhu at Micron Technology led to the development of 30   nm class CMOS in the 2000s. CMOS is used in most modern LSI and VLSI devices. As of 2010, CPUs with

8625-416: The development of faster computers as well as portable computers and battery-powered handheld electronics . In 1988, Davari led an IBM team that demonstrated a high-performance 250 nanometer CMOS process. Fujitsu commercialized a 700   nm CMOS process in 1987, and then Hitachi, Mitsubishi Electric , NEC and Toshiba commercialized 500   nm CMOS in 1989. In 1993, Sony commercialized

8740-477: The device; M. O. Thurston, L. A. D'Asaro, and J. R. Ligenza who developed the diffusion processes, and H. K. Gummel and R. Lindner who characterized the device. There were originally two types of MOSFET logic, PMOS ( p-type MOS) and NMOS ( n-type MOS). Both types were developed by Frosch and Derrick in 1957 at Bell Labs. In 1948, Bardeen and Brattain patented the progenitor of MOSFET, an insulated-gate FET (IGFET) with an inversion layer. Bardeen's patent, and

8855-579: The door can also be used to store a power cable during transit. Power is supplied to the IBM P75 through an IEC C14 socket, the PSU accepts 100-240v 3.0A The IBM P75, like other contemporary PS/2 computers of the period, utilises reference diskettes to make any changes to system settings such as the installed memory size, the assignment of the built-in connectors, and installed options with their location and assignments. System settings are stored in CMOS and data integrity

8970-478: The early 1970s were PMOS processors, which initially dominated the early microprocessor industry. By the late 1970s, NMOS microprocessors had overtaken PMOS processors. CMOS microprocessors were introduced in 1975, with the Intersil 6100 , and RCA CDP 1801 . However, CMOS processors did not become dominant until the 1980s. CMOS was initially slower than NMOS logic , thus NMOS was more widely used for computers in

9085-444: The end of those resistive wires see slow input transitions. Careful design which avoids weakly driven long skinny wires reduces this effect, but crowbar power can be a substantial part of dynamic CMOS power. Parasitic transistors that are inherent in the CMOS structure may be turned on by input signals outside the normal operating range, e.g. electrostatic discharges or line reflections . The resulting latch-up may damage or destroy

9200-469: The external monitor only, it can operate at 800x600 resolution in 16-bit ( high-colour ) in Windows 95 using third party drivers. The keyboard is a 101 key, full size and full travel IBM keyboard and serves as both the keyboard of the unit and the cover of the unit when being transported. It is attached to the computer through a 14-inch rolled-coil cable. Hard disk configurations were available in 2 varieties,

9315-585: The extremely thin gate dielectric. Using high-κ dielectrics instead of silicon dioxide that is the conventional gate dielectric allows similar device performance, but with a thicker gate insulator, thus avoiding this current. Leakage power reduction using new material and system designs is critical to sustaining scaling of CMOS. CMOS circuits dissipate power by charging the various load capacitances (mostly gate and wire capacitance, but also drain and some source capacitances) whenever they are switched. In one complete cycle of CMOS logic, current flows from V DD to

9430-411: The family of processes used to implement that circuitry on integrated circuits (chips). CMOS circuitry dissipates less power than logic families with resistive loads. Since this advantage has increased and grown more important, CMOS processes and variants have come to dominate, thus the vast majority of modern integrated circuit manufacturing is on CMOS processes. CMOS logic consumes around one seventh

9545-468: The first few years the PS/2 was available, and they were very commonly purchased with lower-end models. The VGA connector became the de facto standard for connecting monitors and projectors on both PC and non-PC hardware over the course of the early 1990s, replacing a variety of earlier connectors. Apple had first popularized the 3.5" floppy on the Macintosh line and IBM brought them to the PC in 1986 with

9660-575: The floppy drives. Later models used DBA ESDI or Parallel SCSI . Typically, desktop PS/2 models only permitted use of one hard drive inside the computer case. Additional storage could be attached externally using the optional SCSI interface. Later PS/2 models introduced the 72-pin SIMM which became the de facto standard for RAM modules by the mid-1990s in mid-to-late 486 and nearly all Pentium desktop systems. The 72-pin SIMMs were 32/36 bits wide and replaced

9775-403: The full 101-key keyboard and standalone monitor along with three 8-bit ISA expansion slots. 8086 models had 720 KB floppies while 286 models had 1440 KB ones. Both the Model 25 and 30 could have an optional 20 MB ST-506 hard disk (which in the Model 25 took the place of the second floppy drive if so equipped and used a proprietary 3.5" form factor). 286-based Model 30s are otherwise

9890-411: The immature OS/2 1.x operating system (the more capable OS/2 version 2.0 was not released until 1992) to justify the PS/2's price premium, in contrast to rival IBM PC compatibles that stuck with industry-wide standard hardware while running Microsoft Windows . In 1992, Macworld stated that "IBM lost control of its own market and became a minor player with its own technology." IBM officially retired

10005-522: The input. The transistors' resistances are never exactly equal to zero or infinity, so Q will never exactly equal Vss or Vdd, but Q will always be closer to Vss than A was to Vdd (or vice versa if A were close to Vss). Without this amplification, there would be a very low limit to the number of logic gates that could be chained together in series, and CMOS logic with billions of transistors would be impossible. The power supply pins for CMOS are called V DD and V SS , or V CC and Ground(GND) depending on

10120-412: The large body of existing IBM-compatible software. However IBM made available optional external 5.25" drives, with internal adapters for the early PS/2 models, to enable data transfer. In the initial lineup, IBM used 720 KB double density (DD) capacity drives on the 8086-based models and 1440 KB high density (HD) on the 80286-based and higher models. By the end of the PS/2 line they had moved to

10235-425: The load capacitance to charge it and then flows from the charged load capacitance (C L ) to ground during discharge. Therefore, in one complete charge/discharge cycle, a total of Q=C L V DD is thus transferred from V DD to ground. Multiply by the switching frequency on the load capacitances to get the current used, and multiply by the average voltage again to get the characteristic switching power dissipated by

10350-444: The logic based on De Morgan's laws , the PMOS transistors in parallel have corresponding NMOS transistors in series while the PMOS transistors in series have corresponding NMOS transistors in parallel. More complex logic functions such as those involving AND and OR gates require manipulating the paths between gates to represent the logic. When a path consists of two transistors in series, both transistors must have low resistance to

10465-408: The manufacturer. V DD and V SS are carryovers from conventional MOS circuits and stand for the drain and source supplies. These do not apply directly to CMOS, since both supplies are really source supplies. V CC and Ground are carryovers from TTL logic and that nomenclature has been retained with the introduction of the 54C/74C line of CMOS. An important characteristic of a CMOS circuit

10580-633: The old 30-pin SIMM (8/9-bit) standard. The older SIMMs were much less convenient because they had to be installed in sets of two or four to match the width of the CPU's 16-bit (Intel 80286 and 80386SX ) or 32-bit (80386 and 80486 ) data bus, and would have been extremely inconvenient to use in Pentium systems (which featured a 64-bit memory bus). The 72-pin SIMMs were also made with greater capacities (starting at 1 MB and ultimately reaching 128 MB, instead of 256 KB to 16 MB (and usually no more than 4 MB) for 30-pin) and in

10695-408: The otherwise common intermediate 800 × 600 SVGA resolution, even at the relatively low 50 to 56 Hz refresh rates initially used. Although the design of these adapters did not become an industry standard as VGA did, their 1024 × 768 pixel resolution was subsequently widely adopted as a standard by other manufacturers, and XGA became a synonym for this screen resolution. The only exceptions were

10810-401: The outputs of the PMOS and NMOS transistors are complementary such that when the input is low, the output is high, and when the input is high, the output is low. No matter what the input is, the output is never left floating (charge is never stored due to wire capacitance and lack of electrical drain/ground). Because of this behavior of input and output, the CMOS circuit's output is the inverse of

10925-412: The per-machine royalties. The OS/2 operating system was announced at the same time as the PS/2 line and was intended to be the primary operating system for models with Intel 80286 or later processors. However, at the time of the first shipments, only IBM PC DOS 3.3 was available. OS/2 1.0 (text-mode only) and Microsoft's Windows 2.0 became available several months later. IBM also released AIX PS/2,

11040-583: The power consumption per unit area of the chip has risen tremendously. Broadly classifying, power dissipation in CMOS circuits occurs because of two components, static and dynamic: Both NMOS and PMOS transistors have a gate–source threshold voltage (V th ), below which the current (called sub threshold current) through the device will drop exponentially. Historically, CMOS circuits operated at supply voltages much larger than their threshold voltages (V dd might have been 5 V, and V th for both NMOS and PMOS might have been 700 mV). A special type of

11155-479: The power of NMOS logic , and about 10 million times less power than bipolar transistor-transistor logic (TTL). CMOS circuits use a combination of p-type and n-type metal–oxide–semiconductor field-effect transistor (MOSFETs) to implement logic gates and other digital circuits. Although CMOS logic can be implemented with discrete devices for demonstrations, commercial CMOS products are integrated circuits composed of up to billions of transistors of both types, on

11270-512: The process diagram below right) The contacts penetrate an insulating layer between the base layers and the first layer of metal (metal1) making a connection. The inputs to the NAND (illustrated in green color) are in polysilicon. The transistors (devices) are formed by the intersection of the polysilicon and diffusion; N diffusion for the N device & P diffusion for the P device (illustrated in salmon and yellow coloring respectively). The output ("out")

11385-479: The rise of the Japanese semiconductor industry. Toshiba developed C MOS (Clocked CMOS), a circuit technology with lower power consumption and faster operating speed than ordinary CMOS, in 1969. Toshiba used its C MOS technology to develop a large-scale integration (LSI) chip for Sharp 's Elsi Mini LED pocket calculator , developed in 1971 and released in 1972. Suwa Seikosha (now Seiko Epson ) began developing

11500-632: The standard name for the technology by the early 1970s. CMOS overtook NMOS logic as the dominant MOSFET fabrication process for very large-scale integration (VLSI) chips in the 1980s, also replacing earlier transistor–transistor logic (TTL) technology. CMOS has since remained the standard fabrication process for MOSFET semiconductor devices in VLSI chips. As of 2011 , 99% of IC chips, including most digital , analog and mixed-signal ICs, were fabricated using CMOS technology. Two important characteristics of CMOS devices are high noise immunity and low static power consumption . Since one transistor of

11615-452: The system. The majority of MCA's features would be seen in later buses with the exception of: streaming-data procedure, channel-check reporting, error logging and internal bus-level video pass-through for devices like the IBM 8514 . Transfer speeds were on par with the much later PCI standard. MCA allowed one-to-one, card-to-card, and multi-card to processor simultaneous transaction management which

11730-588: The television show M*A*S*H playing the staff of a contemporary (i.e. late-1980s) business in roles reminiscent of their characters' roles from the series. Harry Morgan, Larry Linville, William Christopher, Wayne Rogers, Gary Burghoff, Jamie Farr, and Loretta Swit were in from the beginning, whereas Alan Alda joined the campaign later. The profound lack of success of these advertising campaigns led, in part, to IBM's termination of its relationships with its global advertising agencies ; these accounts were reported by Wired magazine to have been worth over $ 500 million

11845-438: 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

11960-434: The transistor is on, because there is a current path from V dd to V ss through the load resistor and the n-type network. Static CMOS gates are very power efficient because they dissipate nearly zero power when idle. Earlier, the power consumption of CMOS devices was not the major concern while designing chips. Factors like speed and area dominated the design parameters. As the CMOS technology moved below sub-micron levels

12075-659: The transistor used in some CMOS circuits is the native transistor , with near zero threshold voltage . SiO 2 is a good insulator, but at very small thickness levels electrons can tunnel across the very thin insulation; the probability drops off exponentially with oxide thickness. Tunnelling current becomes very important for transistors below 130 nm technology with gate oxides of 20 Å or thinner. Small reverse leakage currents are formed due to formation of reverse bias between diffusion regions and wells (for e.g., p-type diffusion vs. n-well), wells and substrate (for e.g., n-well vs. p-substrate). In modern process diode leakage

12190-413: The wafer. J.R. Ligenza and W.G. Spitzer studied the mechanism of thermally grown oxides and fabricated a high quality Si/ SiO 2 stack in 1960. Following this research, Mohamed Atalla and Dawon Kahng proposed a silicon MOS transistor in 1959 and successfully demonstrated a working MOS device with their Bell Labs team in 1960. Their team included E. E. LaBate and E. I. Povilonis who fabricated

12305-472: Was annoying, but less expensive and time-consuming than bringing in a PC technician to do installation. But for large organizations with hundreds or even thousands of PCs, permanently matching each PC with its own floppy disk was a logistical nightmare. Without the original, (and correctly updated) floppy disk, no changes could be made to the PC's cards. In addition to the technical setup, legally, royalties were required for each MCA-compatible machine sold. There

12420-442: Was familiar with work done by Weimer at RCA. In 1955, Carl Frosch and Lincoln Derick accidentally grew a layer of silicon dioxide over the silicon wafer, for which they observed surface passivation effects. By 1957 Frosch and Derrick, using masking and predeposition, were able to manufacture silicon dioxide transistors and showed that silicon dioxide insulated, protected silicon wafers and prevented dopants from diffusing into

12535-459: Was nothing unique in IBM insisting on payment of royalties on the use of its patents applied to Micro Channel-based machines. Up until that time, some companies had failed to pay IBM for the use of its patents on the earlier generation of Personal Computer. The PS/2 IBM Model M keyboard used the same 101-key layout of the previous IBM PC/AT Extended keyboard, itself derived from the original IBM PC keyboard . European variants had 102 keys with

12650-489: Was once used but now the material is polysilicon . Other metal gates have made a comeback with the advent of high-κ dielectric materials in the CMOS process, as announced by IBM and Intel for the 45 nanometer node and smaller sizes. The principle of complementary symmetry was first introduced by George Sziklai in 1953 who then discussed several complementary bipolar circuits. Paul Weimer , also at RCA , invented in 1962 thin-film transistor (TFT) complementary circuits,

12765-488: Was outlined, on the basis of thermal oxidation of a silicon substrate to yield a layer of silicon dioxide located between the drain contact and the source contact. CMOS was commercialised by RCA in the late 1960s. RCA adopted CMOS for the design of integrated circuits (ICs), developing CMOS circuits for an Air Force computer in 1965 and then a 288- bit CMOS SRAM memory chip in 1968. RCA also used CMOS for its 4000-series integrated circuits in 1968, starting with

12880-639: Was the first Energy Star compliant personal computer. It had a 50 MHz IBM 486SLC processor, an ISA bus, four PC card slots, and an IDE hard drive interface. The environmentally friendly PC borrowed many components from the ThinkPad line and was composed of recycled plastics, designed to be easily recycled at the end of its life, and used very little power. The IBM PS/2 Server 195 and 295 (IBM 8600) were 486-based dual-bus MCA network servers supporting asymmetric multiprocessing , designed by Parallan Computer Inc . The IBM PC Server 720 (IBM 8642)

12995-442: Was the first computer to use the ROMP-C, which would later be introduced in new RT PC models. During the 1980s, IBM's advertising of the original PC and its other product lines had frequently used the likeness of Charlie Chaplin . For the PS/2, however, IBM augmented this character with the following jingle: How ya gonna do it? PS/2 it! It's as easy as IBM. (Or, "The solution is IBM.") Another campaign featured actors from

13110-709: Was the largest MCA-based server made by IBM, although it was not, strictly speaking, a PS/2 model. It could be fitted with up to six Intel Pentium processors interconnected by the Corollary C-bus and up to eighteen SCSI hard disks. This model was equipped with seven combination MCA/ PCI slots. IBM also produced several portable and laptop PS/2s , including the Model L40 (ISA-bus 386SX), N33 (IBM's first notebook-format computer from year 1991, Model 8533, 386SX), N51 (386SX/SLC), P70 (386DX) and P75 (486DX2). The IBM ThinkPad 700C , aside from being labeled "700C PS/2" on

13225-429: Was transparent to software, so all programs supporting the new standards could run unmodified whichever type of display was attached. On the other hand, whether the display was color or monochrome was undetectable to software, so selection between application displays optimized for color or monochrome, in applications that supported both, required user intervention. These grayscale displays were relatively inexpensive during

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