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8253
The Intel 8253 and 8254 are programmable interval timers (PITs), which perform timing and counting functions using three 16-bit counters. The 825x family was primarily designed for the Intel 8080/8085-processors, but were later used in x86 compatible systems. The 825x chips, or an equivalent circuit embedded in a larger chip, are found in all IBM PC compatibles and Soviet computers like the Vector-06C. In PC compatibles, Timer Channel 0 is assigned to IRQ-0 (the highest priority hardware interrupt). Timer Channel 1 is assigned to DRAM refresh (at least in early models before the 80386). Timer Channel 2 is assigned to the PC speaker. The Intel 82c54 (c for CMOS logic) variant handles up to 10 MHz clock signals. History The 8253 is described in the 1980 Intel "Component Data Catalog" publication. The 8254, described as a superset of the 8253 with higher clock speed ratings, has a "preliminary" data sheet in the 1982 Intel "Component Data Catalog". The 8254 is implement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8085
The Intel 8085 ("''eighty-eighty-five''") is an 8-bit microprocessor produced by Intel and introduced in March 1976. It is software-binary compatible with the more-famous Intel 8080 with only two minor instructions added to support its added interrupt and serial input/output features. However, it requires less support circuitry, allowing simpler and less expensive microcomputer systems to be built. The "5" in the part number highlighted the fact that the 8085 uses a single +5-volt (V) power supply by using depletion-mode transistors, rather than requiring the +5 V, −5 V and +12 V supplies needed by the 8080. This capability matched that of the competing Z80, a popular 8080-derived CPU introduced the year before. These processors could be used in computers running the CP/M operating system. The 8085 is supplied in a 40-pin DIP package. To maximise the functions on the available pins, the 8085 uses a multiplexed address/data (AD0-AD7) bus. However, an 8085 circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PC Speaker
A PC speaker is a loudspeaker built into some IBM PC compatible computers. The first IBM Personal Computer, model 5150, employed a standard 2.25 inch magnetic driven (dynamic) speaker. More recent computers use a tiny moving-iron or piezo speaker instead. The speaker allows software and firmware to provide auditory feedback to a user, such as to report a hardware fault. A PC speaker generates waveforms using the programmable interval timer, an Intel 8253 or 8254 chip. Use cases BIOS/UEFI error codes The PC speaker is used during the power-on self-test (POST) sequence to indicate errors during the boot process. Since it is active before the graphics card, it can be used to communicate "beep codes" related to problems that prevent the much more complex initialization of the graphics card to take place. For example, the Video BIOS usually cannot activate a graphics card unless working RAM is present in the system while beeping the speaker is possible with just R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8080
The Intel 8080 (''"eighty-eighty"'') is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility.'' Electronic News'' was a weekly trade newspaper. The same advertisement appeared in the May 2, 1974 issue of ''Electronics'' magazine. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 (sometimes referred to as the 8080B) and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively. The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. It is implemented in N-type metal-oxide-semiconductor logic (NMOS) usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM PC Compatible
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. The term "IBM PC compatible" is now a historical description only, since IBM no longer sells personal computers after it sold its personal computer division in 2005 to Chinese technology company Lenovo. The designation "PC", as used in much of personal computer history, has not meant "personal computer" generally, but rather an x86 computer capable of running the same software that a contemporary IBM PC could. The term was initially in contrast to the variety of home computer systems available in the early 1980s, such as the Apple II, TRS-80, and Commodore 64. Later, the term was primarily used in contrast to Apple's Macintosh computers. These "clones" duplicated almost all the significant features of the original IBM PC architectures. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector-06C
Vector-06C (russian: Вектор-06Ц) is a home computer with unique graphics capabilities that was designed and mass-produced in USSR in the late 1980s. History Vector-06C was created by Soviet engineers Donat Temirazov and Alexander Sokolov from Kishinev, Moldovan SSR. On 33rd National Radio Exhibition the design was honoured with the grand prize. Shortly after that several factories started production of Vector-06C. In 1988 Vector was honoured a prize on Exhibition of Achievements of the National Economy. There were modifications adopting Zilog Z80 CPU or the unique Soviet KR580VM1 CPU. A commercial project called Vector Turbo+ with a Z80 CPU, clock frequency increased to 6 or 12 MHz, RAM sized up to 2 MiB and a variety of other improvements was in development. However, according to the InVector e-zine, a prototype of this system never left the work bench due to economical reasons. Vector has gradually become less popular with the increasing flow of IBM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local APIC
In computing, Intel's Advanced Programmable Interrupt Controller (APIC) is a family of interrupt controllers. As its name suggests, the APIC is more advanced than Intel's 8259 Programmable Interrupt Controller (PIC), particularly enabling the construction of multiprocessor systems. It is one of several architectural designs intended to solve interrupt routing efficiency issues in multiprocessor computer systems. The APIC is a split architecture design, with a local component (LAPIC) usually integrated into the processor itself, and an optional I/O APIC on a system bus. The first APIC was the 82489DX it was a discrete chip that functioned both as local and I/O APIC. The 82489DX enabled construction of symmetric multiprocessor (SMP) systems with the Intel 486 and early Pentium processors; for example, the reference two-way 486 SMP system used three 82489DX chips, two as local APICs and one as I/O APIC. Starting with the P54C processor, the local APIC functionality was integrated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorburst
Colorburst is an analog video, composite video signal generated by a video-signal generator used to keep the chrominance subcarrier synchronized in a color television signal. By synchronizing an oscillator with the colorburst at the back porch (beginning) of each scan line, a television receiver is able to restore the suppressed carrier of the chrominance (color) signals, and in turn decode the color information. The most common use of colorburst is to genlock equipment together as a common reference with a vision mixer in a television studio using a multi-camera setup. Explanation In NTSC, its frequency is exactly 315/88 = 3.579 MHz with a phase of 180°. PAL uses a frequency of exactly 4.43361875 MHz, with its phase alternating between 135° and 225° from line to line. Since the colorburst signal has a known amplitude, it is sometimes used as a reference level when compensating for amplitude variations in the overall signal. SECAM is unique in not having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 series of instruction sets, the instruction sets found in most personal computers (PCs). Incorporated in Delaware, Intel ranked No. 45 in the 2020 ''Fortune'' 500 list of the largest United States corporations by total revenue for nearly a decade, from 2007 to 2016 fiscal years. Intel supplies microprocessors for computer system manufacturers such as Acer, Lenovo, HP, and Dell. Intel also manufactures motherboard chipsets, network interface controllers and integrated circuits, flash memory, graphics chips, embedded processors and other devices related to communications and computing. Intel (''int''egrated and ''el''ectronics) was founded on July 18, 1968, by semiconductor pioneers Gordon Moore (of Moore's law) and Robert Noyce ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Interval Timer
In computing and in embedded systems, a programmable interval timer (PIT) is a counter that generates an output signal when it reaches a programmed count. The output signal may trigger an interrupt. Common features PITs may be one-shot or periodic. One-shot timers will signal only once and then stop counting. Periodic timers signal every time they reach a specific value and then restart, thus producing a signal at periodic intervals. Periodic timers are typically used to invoke activities that must be performed at regular intervals. Counters are usually programmed with fixed intervals that determine how long the counter will count before it will output a signal. IBM PC compatible The Intel 8253 PIT was the original timing device used on IBM PC compatibles. It used a 1.193182 MHz clock signal (one third of the color burst frequency used by NTSC, one twelfth of the system clock crystal oscillator, therefore one quarter of the 4.77 MHz CPU clock) and contains three timers. Timer 0 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8253 And 8254
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 series of instruction sets, the instruction sets found in most personal computers (PCs). Incorporated in Delaware, Intel ranked No. 45 in the 2020 ''Fortune'' 500 list of the largest United States corporations by total revenue for nearly a decade, from 2007 to 2016 fiscal years. Intel supplies microprocessors for computer system manufacturers such as Acer, Lenovo, HP, and Dell. Intel also manufactures motherboard chipsets, network interface controllers and integrated circuits, flash memory, graphics chips, embedded processors and other devices related to communications and computing. Intel (''int''egrated and ''el''ectronics) was founded on July 18, 1968, by semiconductor pioneers Gordon Moore (of Moore's law) and Robert Noyce (1927–1990) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8253 Block Diagram
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 series of instruction sets, the instruction sets found in most personal computers (PCs). Incorporated in Delaware, Intel ranked No. 45 in the 2020 ''Fortune'' 500 list of the largest United States corporations by total revenue for nearly a decade, from 2007 to 2016 fiscal years. Intel supplies microprocessors for computer system manufacturers such as Acer, Lenovo, HP, and Dell. Intel also manufactures motherboard chipsets, network interface controllers and integrated circuits, flash memory, graphics chips, embedded processors and other devices related to communications and computing. Intel (''int''egrated and ''el''ectronics) was founded on July 18, 1968, by semiconductor pioneers Gordon Moore (of Moore's law) and Robert Noyce (1927–1990) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monostable Multivibrator
A multivibrator is an electronic circuit used to implement a variety of simple two-state devices such as relaxation oscillators, timers, and flip-flops. The first multivibrator circuit, the astable multivibrator oscillator, was invented by Henri Abraham and Eugene Bloch during World War I. It consisted of two vacuum tube amplifiers cross-coupled by a resistor-capacitor network. They called their circuit a "multivibrator" because its output waveform was rich in harmonics. A variety of active devices can be used to implement multivibrators that produce similar harmonic-rich wave forms; these include transistors, neon lamps, tunnel diodes and others. Although cross-coupled devices are a common form, single-element multivibrator oscillators are also common. The three types of multivibrator circuits are: * Astable multivibrator, in which the circuit is not stable in either state —it continually switches from one state to the other. It functions as a relaxation oscillator. * Monos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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