In computing, a waveform buffer is a technique for digital synthesis of repeating waveforms. It is common in PC sound cards.
Computing is any activity that uses computers to manage, process, and communicate information for various purposes. It includes development of both hardware and software. Computing is a critical, integral component of modern industrial technology. Major computing disciplines include computer engineering, software engineering, computer science, information systems, and information technology.
Repeating waveforms is a technique for digital synthesis common in PC sound cards.
A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large costly minicomputer and mainframes, time-sharing by many people at the same time is not used with personal computers.
The waveform amplitude values are stored in a buffer memory, which is addressed from a phase generator, with the retrieved value then used as the basis of the synthesized signal. In the phase generator, a value proportional to the desired signal frequence is periodically added to an accumulator. The high order bits of the accumulator form the output address, while the typically larger number of bits in the accumulator and addition value results in an arbitrarily high frequency resolution.
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. Most radio systems in the 20th century used frequency modulation (FM) or amplitude modulation (AM) for radio broadcast.
A signal generator is an electronic device that generates repeating or non-repeating electronic signals in either the analog or the digital domain. It is generally used in designing, testing, troubleshooting, and repairing electronic or electroacoustic devices, though it often has artistic uses as well.
In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time.
The Intel 8085 ("eighty-eighty-five") is an 8-bit microprocessor produced by Intel and introduced in 1976. It is a 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 MOS Technology 6581/8580 SID is the built-in programmable sound generator chip of Commodore's CBM-II, Commodore 64, Commodore 128 and Commodore MAX Machine home computers. It was one of the first sound chips of its kind to be included in a home computer prior to the digital sound revolution.
A numerically controlled oscillator (NCO) is a digital signal generator which creates a synchronous, discrete-time, discrete-valued representation of a waveform, usually sinusoidal. NCOs are often used in conjunction with a digital-to-analog converter (DAC) at the output to create a direct digital synthesizer (DDS).
A voltage-controlled oscillator (VCO) is an electronic oscillator whose oscillation frequency is controlled by a voltage input. The applied input voltage determines the instantaneous oscillation frequency. Consequently, a VCO can be used for frequency modulation (FM) or phase modulation (PM) by applying a modulating signal to the control input. A VCO is also an integral part of a phase-locked loop.
Continuous phase modulation (CPM) is a method for modulation of data commonly used in wireless modems. In contrast to other coherent digital phase modulation techniques where the carrier phase abruptly resets to zero at the start of every symbol, with CPM the carrier phase is modulated in a continuous manner. For instance, with QPSK the carrier instantaneously jumps from a sine to a cosine whenever one of the two message bits of the current symbol differs from the two message bits of the previous symbol. This discontinuity requires a relatively large percentage of the power to occur outside of the intended band, leading to poor spectral efficiency. Furthermore, CPM is typically implemented as a constant-envelope waveform, i.e., the transmitted carrier power is constant. Therefore, CPM is attractive because the phase continuity yields high spectral efficiency, and the constant envelope yields excellent power efficiency. The primary drawback is the high implementation complexity required for an optimal receiver.
The Motorola 6845, or MC6845, is a display controller that was widely used in 8-bit computers during the 1980s. Although intended for designs based on the Motorola 6800 CPU and given a related part number, it was more widely used alongside various other processors, and was most commonly found in machines based on the Zilog Z80 and MOS 6502.
A memory buffer register (MBR), commonly referred to as a memory data recogniser (MDR) is the register in a computer's processor, or central processing unit, CPU, that stores the data being transferred to and from the immediate access storage. It contains the copy of designated memory locations specified by the memory address register. It acts as a buffer allowing the processor and memory units to act independently without being affected by minor differences in operation. A data item will be copied to the MBR ready for use at the next clock cycle, when it can be either used by the processor for reading or writing or stored in main memory after being written.
Direct digital synthesis (DDS) is a method employed by frequency synthesizers used for creating arbitrary waveforms from a single, fixed-frequency reference clock. DDS is used in applications such as signal generation, local oscillators in communication systems, function generators, mixers, modulators, sound synthesizers and as part of a digital phase-locked loop.
A function generator is usually a piece of electronic test equipment or software used to generate different types of electrical waveforms over a wide range of frequencies. Some of the most common waveforms produced by the function generator are the sine wave, square wave, triangular wave and sawtooth shapes. These waveforms can be either repetitive or single-shot. Integrated circuits used to generate waveforms may also be described as function generator ICs.
The UNIVAC 418 was a transistorized, 18-bit word core memory machine made by Sperry Univac. The name came from its 4-microsecond memory cycle time and 18-bit word. The assembly language for this class of computers was TRIM III and ART418.
Delta-sigma modulation is a method for encoding analog signals into digital signals as found in an analog-to-digital converter (ADC). It is also used to convert high bit-count, low-frequency digital signals into lower bit-count, higher-frequency digital signals as part of the process to convert digital signals into analog as part of a digital-to-analog converter (DAC).
The HuC6280 8-bit microprocessor is Japanese company Hudson Soft's improved version of the WDC 65C02 CPU, an upgraded CMOS version of the popular NMOS-based MOS Technology 6502 8-bit CPU manufactured for Hudson by Seiko Epson. The most notable product using the HuC6280 is NEC's TurboGrafx-16 video game console.
An arbitrary waveform generator (AWG) is a piece of electronic test equipment used to generate electrical waveforms. These waveforms can be either repetitive or single-shot in which case some kind of triggering source is required. The resulting waveforms can be injected into a device under test and analyzed as they progress through it, confirming the proper operation of the device or pinpointing a fault in it.
The Coupland Digital Music Synthesizer is a 16-voice polyphonic real-time instrument with a full 88 key keyboard, developed in the 1970s but never released commercially.
A digital signal is a signal that is being used to represent data as a sequence of discrete values; at any given time it can only take on one of a finite number of values. This contrasts with an analog signal, which represents continuous values; at any given time it represents a real number within a continuous range of values.
PicoScope is computer software for real-time signal acquisition of Pico Technology oscilloscopes. PicoScope is supported on Microsoft Windows, Mac OS X, Debian and Ubuntu platforms. PicoScope is primarily used to view and analyze real-time signals from PicoScope oscilloscopes and data loggers. PicoScope software enables analysis using FFT, a spectrum analyser, voltage-based triggers, and the ability to save/load waveforms to disk. PicoScope is compatible with parallel port oscilloscopes and the newer USB oscilloscopes.