Yamaha DX7 Product Manual - Page 66

Load In the DX7, "Load" describes the process of trans- Parameter In general terms, a parameter is any defin- internal memory (although that is, in fact, a RAM mem- 61 ferring the 32 voices from one bank of a ROM cartridge, able characteristic of a device or system. In the DX syn- ory). Instead, the term refers to an electronic secondary or from a RAM cartridge, into the 32 internal memories. thesizers, "performance parameters" refer to those memory - the EEPROM cartridge - and its size is MIDI This is an acronym for Musical Instrument Digital Interface, a specification which several manufacturers have already agreed to use for designing equipment which is compatible. MIDI is a non-proprietary "language" which allows different (or identical) synthesizers to "talk" to each other. MIDI-compatible instruments made by any one manufacturer should generally be capable of causing other manufacturers' MIDI-compatible instruments to play, and to switch from one voice to the next. Computer or sequencer control of multiple synthesizers will be possible using MIDI. Within a single manufacturer's product line, such as the Yamaha DX series, MIDI can permit extensive programming of one instrument through the controls of another by com- municating so-called "system exclusive" information; characteristics of the instrument that, when adjusted from the FUNCTION mode, affect the overall keyboard - or at least affect more than a single voice. For example, adjusting the keyboard's pressure sensitivity (After Touch) is considered to be a "performance parameter" because it affects any voice which is programmed to be modulation sensitive. "Editing parameters" refer to those characteristics that can be programmed for an individual voice when the instrument is in the EDIT mode (such as the choice of an algorithm). PLAY mode In the DX7, this is the operating mode from which you can select and play voices stored in a cartridge or an internal memory. You select PLAY mode by pressing either [MEMORY SELECT-INTERNAL] OR [MEMORY SELECT-CARTRIDGE]. defined not in bytes, but in voices. The RAM cartridges each hold 32 voices. The RAM cartridges are truly random access memories since each voice can be written to or read from the cartridge independently of the others, or all 32 voices may be moved at once. However, the DX7 RAM cartridges differ from conventional RAM in that the cartridges retain their memory after power is turned off, without the use of backup batteries. Release In a synthesizer, this is the time it takes for the note to die away after you let go of the key In the DX7, rate 4 of the envelope is equivalent to the release rate; the release time will depend on the level at the moment the key is released, since, for a given rate. the time is greater if the level is greater. when dissimilar synthesizers are fed this type of information, they simply ignore it. Modulation This is the process of varying one signal with another. See "Frequency Modulation." Modulation Index This refers to the ratio between the PMD This is an abbreviation for "Pitch Modulation Depth." Higher PMD values apply more LFO modulation toward changing the pitch of a voice when you play a note, provided the [MODULATION SENSITIVITYPITCH] setting is greater than zero. ROM This is an acronym for "Read Only Memory." In computers, ROM is generally provided for storage of small to medium sized, often-used programs such as self-test routines, BASIC language, input/output drivers, and so forth. ROM is generally provided on 1C chips that cannot be altered. In the DX7, the factory "preset" voices output level of a modulator and the level of the carrier Preset A preset is a voice which can be played without are stored in ROM chips inside the ROM cartridges. which it is modulating. The greater the modulation having to be programmed. Some synthesizers force the Each of these cartridges holds 64 voices. Simple ROM index, the more harmonics are produced (the wider the player to program any voice which is to be played. chips can only be programmed at the time of manufac- bandwidth of the FM-generated complex tone). When Other instruments have only factory presets - basically ture, like those in the DX7 voice ROM cartridges. Semi- you turn up the level of a modulator, you increase the fixed, unalterable voices. Still other synthesizers offer a ROM chips can be programmed after their manufacture modulation index. combination of programmable and preset voices. The by using special equipment; these are known as PROMS Modulator In general terms, this is the circuit which allows one signal to modulate another. In the DX synthesizers, a modulator is an operator which sends its signal to another operator (either another modulator or a carrier) rather than directly to the output. The only thing that differentiates a modulator from a carrier is its position within the algorithm; carriers are on the bottom row of the stack(s) and modulators are above them. DX synthesizers go a step further. They offer complete programmability plus presets (in the form of internal and cartridge memories on the DX7), but the presets are, themselves, completely programmable. Because the DX preset voices can be edited, a better term might be "primary voices." Yamaha uses the term "preset" only because it is familiar to synthesists, and the DX series require enough new terminology without coining another new term. (Programmable Read Only Memories). Some PROMs can also be erased (usually by exposure to ultra- violet light) and can then be reprogrammed; these are known as EPROMs (Eraseable Programmable Read Only Memo- ries). Finally, some EPROMs are electrically eraseable so that they can be reprogrammed easily without special equipment; these are called EEPROMs (Electrically Eraseable Progrmmable Read Only Memory) - and Yamaha calls them RAM in the DX7, although they OP This is an abbreviation; see "operator." Operator This is a functional block within the circuitry of the DX synthesizer. An operator can be thought of as an oscillator, but it is somewhat more complex. It is RAM This is an acronym for "Random Access Memory" In computers, RAM is the "main memory" the solid state area where programs are stored while they are active, and where data is temporarily stored until it is trans- differfromconventional RAM(seeRAMdefinition). EEPROMs may also be called EAROMs (Electrically Alterable Read Only Memories). Sample and hold This is a random "waveform." It actually a digital sine wave oscillator which includes a digital envelope generator. The frequency and output level of an operator are adjustable. Operators actually have multiple inputs so that they can be fed signals from ferred to secondary storage such as a floppy disk, hard disk, magnetic bubble memory or magnetic tape. Such computer RAM memories are ususally categorized in terms of how many bytes of 8 bits each they can store; a jumps from one level to another in a non-periodic fashion, unlike the regular, uniform changes in level associated with sine, sawtooth, square or triangle waves. In the DX synthesizers, a sample and hold signal may be more than one source (i.e., an operator serving as a 1K RAM holds about 1,000 bytes (actually 1K is 1,024 selected for use in the LFO section. carrier may accept signals from two or three modulators). The DX7 has 6 operators, all identical. bytes). In the DX synthesizers, RAM does not refer to the