<p> W080/106</p><p>DUBLIN INSTITUTE OF TECHNOLOGY KEVIN STREET, DUBLIN 8</p><p>B. Eng. Tech. Degree in Electronics and Computer Systems</p><p>YEAR 1</p><p>SEMESTER 1 EXAMINATIONS 2006</p><p>MUSIC TECHNOLOGY</p><p>Mr. T. Scarff</p><p>Attempt THREE questions</p><p>33 marks per question W080/106</p><p>1. (a) Describe and explain how the Musical Instrument Digital Interface (MIDI) messages are transmitted as serial data. The MIDI Note On message has a Status Byte of 1001nnnn, where the MIDI channels (nnnn) 1 to 16 are represented in binary as 0000 to 1111. Draw a timing diagram and detail the MIDI message (3 bytes) in binary, and corresponding hexadecimal, if a Note On message for note 60, with a velocity of 64 on channel 16 is generated. [13 marks]</p><p>(b) Explain the purpose and operation of running status in a MIDI system. [7 marks]</p><p>(c) The Pitch-bend MIDI Message has a Status Byte of 1110nnnn. Detail the contents of the complete message including the data bytes. Calculate the length of time it would take to transmit the MIDI data if the pitch-bend wheel is moved from a central to the maximum position (assuming operation in running status mode).</p><p>[13 marks] W080/106</p><p>2. (a) Draw typical circuit diagrams for MIDI hardware In, Out and Thru circuits. What are the advantages of the MIDI current loop system? [10 marks]</p><p>(b) Draw block diagrams, explain and compare the daisy-chain and star methods of MIDI distribution. Explain the problem of slew rate smearing errors in the distribution of MIDI signals. [10 marks]</p><p>(c) Describe the operation of a wavetable synthesiser. Explain the following terms used in wavetable synthesis:</p><p>(i) Looping, (ii) Interpolation, (iii) Oversampling, (iv) Split points. [13 marks]</p><p>3. (a) Draw a block diagram of an analogue subtractive synthesiser. [10 marks]</p><p>(b) Explain the operation of the ADSR section to control the Voltage Controlled Amplifier (VCA) in an analogue subtractive synthesiser.</p><p>[13 marks]</p><p>(c) Detail and draw the frequency components contained in a 100 Hz sawtooth waveform. If the fundamental frequency component of a 100 Hz sawtooth waveform is +5dB, calculate the amplitude of the 9th harmonic when the signal is fed through a first order Low Pass Filter, with a cut-off frequency of 450 Hz, which has a passband gain of 0dBs. W080/106</p><p>[10 marks]</p>