It also has a 1 second Slow and a.125 second Fast time constant circuit. Present OSHA requirements specify Slow.

Microcomputer Modes

The M-27 is controlled by a MC146805 CMOS Microcomputer. The system has 8192 bytes of RAM, 6144 bytes of ROM, a 33-segment LCD, 24 programming switches, serial and parallel printer outputs, a V/F converter for continuous dose integration, and power down circuits to retain data when off.

The M-27 operates in one of the following 6 modes.

Reset Mode

The M-27 enters the reset mode when the unit is reset or a battery is installed. In this mode power is applied to the unit, all previous data is cleared, the internal switches are read, the counter is cleared, the pause register is set, three dashes are placed on the display, and the unit enters the wait mode.

Wait Mode

The microcomputer waits for an interrupt to occur. During the wait mode it continues to gather data from the voltage to frequency converter. Otherwise the microcomputer is in a low power state. When the 1/16 second interrupt occurs the unit enters the pause or run mode.

Pause Mode

In this mode, the Slow or Fast time constant sound level is computed and pause time and the elapsed or real time clocks are incremented. At every interrupt the keyboard is checked to see if any key is pressed - unless it is doing a previous calculation such as sound level when it may delay for up to 1 second. If a key is pressed the computer enters the compute mode. Otherwise it returns to the wait mode.

Run Mode

The same as the pause mode except the data necessary to compute Lavg, Leq, Dose, TWA, SEL, Peak, Max, Run Time, Upper Limit, as well as Event data is accumulated.

Compute Mode

If a key has been pressed in the pause or run modes, the M-27 will compute and display the desired function. If the key is held down it will recompute it one second later using the data accumulated during that second. If the data will not compute (as an example, Lavg will not compute if the sound level never exceeds the threshold level) the display will either show three dashes or display LO.

If the print key has been pressed, the processor will compute one line of print and send the data to the printer output. The printer output may be terminated by pressing the ON/OFF key until 0-5 is displayed. Pressing PAUSE will cause the printer to stop. Press PAUSE to continue. When PSE is displayed, the unit draws extra current and should not be left in this state. ON/OFF will exit PSE. The computer continues to accumulate data during a printout. For best results the computer should be placed in the pause mode during a printout.

When computing is completed, the processor returns to the wait mode.

Stop Mode

If the ON/OFF key has been depressed for 5 seconds, the M-27 enters the stop mode. In the stop mode the processor stops accumulating, but does not erase, data. Power is removed from the analog circuitry and the display circuitry. The oscillator is stopped. Only a few microamps of current are drawn from the battery to maintain the microcomputer's memory and to power the ON/OFF key.

When the ON/OFF key is then pressed the computer returns to where it was before it was turned off except it will be in the pause mode.

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AudioQuest M-27 specifications Microcomputer Modes
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M-27 specifications

AudioQuest M-27 is a standout speaker designed for audiophiles who demand high performance and exquisite sound quality. As part of AudioQuest's commitment to providing unparalleled audio experiences, the M-27 blends advanced technologies with premium materials to deliver exceptional musical clarity and accuracy.

One of the key features of the M-27 is its innovative driver design, which utilizes a new-generation ceramic cone. This cone is engineered to minimize distortion while enhancing transient response. The result is a speaker that offers a clear, detailed sound across a wide frequency range. The drivers are also matched with an advanced neodymium magnet system, ensuring efficient energy transfer and improved bass response.

The M-27 is equipped with a sophisticated crossover network that has been meticulously designed to maintain the integrity of the audio signal. By employing high-quality components, including precision resistors and capacitors, the crossover effectively divides the audio signal into specific frequency bands, allowing each driver to perform at its best. This attention to detail not only enhances sound quality but also helps to create a more cohesive listening experience.

Another notable characteristic of the M-27 is its sturdy and well-constructed cabinet. Built from high-density MDF, the cabinet is engineered to minimize resonance and vibration, which can color sound. Moreover, AudioQuest has incorporated internal bracing to further enhance structural integrity. The elegantly finished exterior not only adds to the speaker's aesthetic appeal but also serves to complement various home decors.

Connectivity is made simple with the M-27, thanks to its standard speaker terminals that accommodate a wide range of wire gauges. This flexibility allows audiophiles to use their preferred cables for optimal performance. Additionally, the speaker is designed to work seamlessly with a variety of amplifier configurations, making it an adaptable choice for different audio setups.

Incorporating these advanced technologies and design principles, the AudioQuest M-27 is not just a speaker; it's a gateway to an immersive listening experience. With its ability to reproduce sound with remarkable accuracy, it will appeal to discerning listeners looking to elevate their audio playback and enjoy their favorite music in a whole new light. Overall, the M-27 stands as a testament to AudioQuest's dedication to crafting high-quality audio products that meet the needs of serious music enthusiasts.
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