Expressions of Interest: Synth Building Workshop - Early 2014 in Adelaide

We're considering organising a 'Modular Synth - Electronic Building Workshop' with Elijah Vartto in early 2014 (possible dates: Feb 10 to 21).

The workshop would be run in 3-hour sessions over 5 days  (after hours) (15 hours in total) and would involve building your own synth (similar vein to http://tinyurl.com/weirdsynth) with demonstrations and support by Elijah Vartto.

The workshop would cost around $150 per person with parts synth parts included in the price (students would have to provide their own case)."

If you are interested, can commit the time and money, please let me know at: sebastian.tomczak@adelaide.edu.au 

Places are limited so first in best dress.







More Detail from Elijah:
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I have worked on building electronic analogue instruments and modular synths, from PCB (printed circuit board) kits, in bursts of enthusiasm ever since joining the VICMOD group in Melbourne in 2006-7. VICMOD are an active group of modular synth building aficionados that meet monthly on a Sunday; affectionately termed 'Nerd Club' by some participants, it involves a lot of exchange of ideas and show and tell, bringing all kinds of built and bought instruments such as the AKS-synthi, loads of vintage synths, Doepfer modules and many more.

It was at these meetings that I was shown a glorious instrument built rather modestly into a VCR video case. It was a Weird Sound Generator, built from the Music From Outer Space designed kit. The beauty of the instrument is that it is a stand alone instrument not requiring a plethora of synth modules before a sound of real 'timbre' could be produced. This was rich, possessing six oscillators, two of which are designated to modulate with two other oscillator voices, all subject to the flick of more than one switch. In addition to this modulating aspect, it has a 'Low Pass Filter' with resonance built in. I then went on to build my own in addition to the other modular synth units through VICMOD.

In the course of living abroad I conducted a workshop on building the WSG through Plektrum Festival in Estonia in 2009. Approximately 12 people participated and all finished with a working instrument at the end. This despite the majority having never picked up a soldering iron. I fixed mistakes of soldering, and coached them to successfully complete their instruments.

For this workshop proposed in February, all electronic components, wiring and PCB will be provided, with guidance from myself on techniques of soldering and construction. The novice and naive should not be afraid. A great working instrument with a rich diversity of sonic qualities will be the result, and a realisation that building your own instrument is not the arcane art-form you might have first thought. The only consideration you must make is how would you like to enclose the instrument? Here you can be creative, functional, fancy or modest. VCR case, lunchbox, shoe-box, cigar box, cookie tin, teddy bear, these can all work, or if you like make your own box.

Do A Heaps PhD Graduation

Can You Imagine, It's A Hard-Bound Chipmusic Doctorate Thesis!

Earpoke 2009 Roundup - incl. Video!

We had the annual Earpoke music concert last night, which is basically the end of year show for the Electronic Music Unit. A number of groups performed, but for me the highlights were the two solo performances - one by Stephen Whittington (who did a 'rap') and one by Tristan Louth-Robins (who did live processing using a bare wire as a sound source). All in all, it was a fun and inspirational night.

Below you can see a few pics and a video of when Poppi Doser and I opened the evening with a few tracks from our forthcoming release.

Tomczak speaks at the postgrad forum

I presented at postgraduate forum today for thirty minutes.

Martin Victory and Poppi Doser Present at PG Forum

Martin Victory and Poppi Doser presented at the music postgraduate forum yesterday. I really enjoyed hearing about their respective topics (the role of speech and speec synthesis in computer music (Victory) and acoustic ecology, specifically in a local context (Doser). Both presentations inspired me.

Tomczak Speaks At Forum

I spoke at music technology forum today at university.

The things I spoke about included:

• Electrofringe in Newcastle, 2008
• Sound Bytes Round 1 in Melbourne, 2008
• International Computer Music Conference in Belfast, 2008
• TechFest in Mumbai, 2009
• Arduino
• Arduino Drum Machine
• Arduino Dot Matrix Printer Rhythm Machine
• Arduino VGA Generation
• Arduino VGA Hacking
• Chiptune Technology
• EPROM Music
• Milkcrate Project

It didn't go too badly.

EMU Earpoke 2008 :: This Wednesday

If you are in Adelaide, please come along.

I will be playing some Sega Master System music.

I Presented a Paper and a Piece at ICMC2008

I presented today at the 2008 International Computer Music Conference. The topic of my paper was "Emulation and Authenticity: Chiptune in the Early Twenty-first Century". It is quite a general paper, aimed at a general audience (ie. people that may or may not have heard of chipmusic before).

I also had a piece in this year's ICMC2008 - "Eleven Point Six Milliseconds", which is also known as "The Emphasis on Small Things" from my Automaton EP.

ICMC2008 Highlights

Just my personal picks - a number of presentations that i enjoyed. Of particular interest and inspiration was the keynote presentation by Trevor Wishart.

Highlights Day 1 -
Autonomous Development of Singing-like Intonations By Interacting Babbling Robots (Miranda);
The Cyclotron: A Tool for Playing with Time (Trueman);

Highlights Day 2 -
An Overview of Networked Music (Kim-Boyle);
Playing the Network (Caceres / Renaud);

Highlights Day 3 -
Do Mobile Phones Dream of Electric Orchestras? (Wang / Essl / Penttinen);
Composing and Computers: A Hopeful Traveller's Report (Wishart)

Highlights Day 4 -
Investigating Artistic Potential of the Dream Interface: The Aural Painting (Bukvic / Gracanin / Quek)
Textural Composition: Implementation of an Intermediary Aesthetic (Hagan)

Highlights Day 5 -
The Enigma of Vitruvian Resonating Vases and the Relevance of the Concept for Today (Godman)
What Is An Event? The Event Schema, Circumstances, Metaphor And Gist (Kendal)

ICMC08

I have had a musical work accepted for the International Computer Music Conference 2008.

ICMC08

I have had a peer-reviewed paper accepted for the International Computer Music Conference 2008.

Music Techies @ PG Seminar

So yesterday Poppi Doser and Tyrell Blackburn gave their honours presentations.

It was quite nice to hear some music technology students at the postgraduate forum. The only other student i have heard in this forum is Tristan Louth-Robins.

Well done, people.

Last night's earpoke concert

Last night was the end-of-year Electronic Music Unit concert. I thought it was a relatively interesting evening as it is great for everyone to hear what everyone else is up to. Although i did forget to bring my ear plugs.

Highlights for me included works by Jake Morris, Ben Probert and Luke Harrald (performed with Derek Pascoe).

Protocol 0.01a

I have been working on ways of getting more data into the Vectrex by extending how data is mapped from the computer to the buttons and thus to RAM location $C807.

The main structure of this protocol is as follows:

• Single 8 bit byte
• Bits 2 - 7 form the data part of the byte
• This holds the range of data that should be mapped to some parameter as shown in the command part of the byte
  
• Bits 0 - 1 form the command part of the byte
• This indicates which parameter the data part of the byte should control
• The range of data and types of parameters are listed in the table below
  

This method of data transfer is a little more dangerous than my previous attempts in that more can go wrong in the transmission. However, the rewards far outshine the negative aspects at this point.

• Monophonic ie. only one note can be played at a time (unchanged)
• Choice of 16 steps of volume (unchanged)
• Choice of 1024 different pitches (up from 16 previously)
• Choice of noise or tone (no choice previously)
• Choice of 32 different noise-shaping steps (up from 16 previously)
  

Of course, this protocol requires a different Max/MSP patch in order to convert generic contrl information into the custom protocol 0.01a. This can be seen below.



Below, you can see a video of the protocol 0.01a in use.

Earpoke 2007

Overview of the Interface and Protocol

Introduction
The interface is made up of one hardware component and three software components. The four components operate in accordance to a predetermined, custom protocol for delivering and receiving information relevant to the production of musical material from the host computer system to the Vectrex videogame console. The protocol is a description of the order and method of information flow from one place to another.



Limitations
The current prototype interface is considerably limited. It is restricted in the following ways.

• Monophonic capability (ie. only one note can be played at a time out of a theoretically* possible three)
• Four-bit pitch set (ie. only sixteen different pitches can be played out of a theoretically possible 4096)

However, it should be noted that the system is in its infancy in terms of development. The interface also incorporates some positive aspects. The reaction time of the interface is fast since only one byte of information is required to be sent and received successfully in order to generate a sound or a change in a sound. Secondly, the four-bit volume control allows for complex volume envelopes that are generated by a host computer program (see Software Overview: Host Computer Patch).

A number of data routing and control techniques will be implemented in order to overcome these limitations in the near future.



Software Overview: Host Computer Patch
The host computer patch acts as a mediator between MIDI data and the microcontroller stage (see: Software Overview: Microcontroller). The MIDI data may be played in by the user in real time or may be pre-sequenced or algorithmically generated in some fashion. The Max/MSP patch titled VECENV reacts to note on, note off and certain continuous control messages.

Each note on and note off event contains two important bytes of data – the velocity and the note number (pitch). For a note on event, the velocity will be a number between 1 and 127. For a corresponding note off event, the velocity will be 0. The pitch byte in both cases is a number between 0 and 127.

The patch examines the pitch byte of the incoming MIDI note and takes the modulo 15 value. This value then becomes the 4-bit frequency nibble that is eventually sent to the Vectrex console (see: Protocol Overview).

A non-zero velocity value from the incoming MIDI note triggers a 32-stage, 4-bit custom volume envelope. This envelope is represented graphically to the user in an editable form. A zero velocity value from the incoming MIDI note sets the output to 0. The data from the volume envelope forms the 4-bit volume nibble that is eventually sent to the Vectrex console (see: Protocol Overview).

The VECENV patch includes a set of 16 presets containing information regarding the shape of the volume envelope. These presets can be accessed via the graphic user interface or by using MIDI Continuous Controller number 16 (General Purpose Slider #1). The range of data from 0 to 127 is scaled to a value between 0 and 15. This value sets the preset from 0 to 15. The default envelope shape preset is 0, which contains a value of 15 for the first step of the envelope and 0 for the remaining steps.

The user is able to alter the speed at which the volume envelope is read through. This is expressed in milliseconds per envelope step and a value from 10ms to 220ms is allowed. The speed parameter can be accessed via the graphic user interface or by using MIDI Continuous Controller number 17 (General Purpose Slider #2). The range of data from 0 to 127 is scaled to a value between 10ms and 220ms. The default speed value is 10ms.

The user is able to alter the length of the volume envelope. This parameter sets how many of the 32 steps are read through before either looping or muting occurs and is defined by a value between 0 and 31. The length parameter can be accessed via the graphic user interface or by using MIDI Continuous Controller number 18 (General Purpose Slider #3). The range of data from 0 to 127 is scaled to a value between 0 and 31. The default value for the length parameter is 31 (representing the full length of the volume envelope).

The user is able to set the volume envelope to loop mode. If the envelope is set to loop mode then the steps of the envelope will wrap-around indefinitely, so long as a note-off event has not been received. This allows for longer, held notes. The loop mode toggle can be accessed via the graphic user interface or by using MIDI Continuous Controller number 19 (General Purpose Slider #4). The range of data from 0 to 127 is scaled to either 0 (for values below 64) or 1 (for values above or equal to 64). If the resulting value is 0, then loop mode is set to off. If the resulting value is 1, then the loop mode is turned on. The loop mode is off by default.

The user is able to scale the output of the volume envelope by a number between 0 and 15. This parameter is called volume and allows for effective control over fade-ins, fade-outs and mixing levels for the Vectrex voice that is being played. The volume parameter can be accessed via the graphic user interface or by using MIDI Continuous Controller number 1 (Modulation). The range of data from 0 to 127 is scaled to a value between 0 and 15. The default value for the volume parameter is 15.

The following table summarises the current MIDI implementation of the VECENV patch.




Software Overview: Microcontroller
The microcontroller software acts as a mediator between the host computer Max/MSP patch VECENV and the bridging circuit (see: Hardware Overview: Bridging Circuit). The microcontroller software has been written in the Arduino environment for use with an Arduino NG or similar interfacing board. An Arduino allows for the translation of digital data into electrical signals.

The sketch (Arduino program) takes the data byte from the Max/MSP VECENV patch containing pitch and volume data and transfers it to the Vectrex via the bridging hardware using electrical states. It should be noted that pins 0 and 1 cannot be used within the Arduino program to send the byte to the Vectrex as these pins are used to transfer the information from the host computer. Thus, PORTB (pins 8 to 15) have to be used in conjunction with PORTD (pins 0 – 7), even though only eight bits are being set.

/*
VECENV TO VSOUNDER CONVERTER by Sebastian Tomczak 26 October 2007
*/

byte data;
// set up a space for data to be tranferred
void setup() {
// begin the setup function
Serial.begin(57600);
// open up a serial connection
DDRD = B11111110;
// set the direction of the PORTD pins (0 - 7)
DDRB = B00000011;
// set the direction for the PORTB pins (8 - 15)}
void loop() {
// begin the loop function
if(Serial.available() > 0) {
// if a serial byte has been received in the serial buffer, then...
data = Serial.read();
// read the byte into memory
PORTD = (data << portb =" (data">> 6) & B00000011;
// set the PORTB pins 0 - 1 to the most significant two bits}}

/* END */
Code 1: The Arduino Sketch



Hardware Overview: Bridging Hardware
The bridging hardware acts as a mediator between the micrcontroller software and the Vectrex itself (see Software Overview: Vectrex Binary). In essence, the interfacing hardware allows the Arduino board to send data to the Vectrex console by directly manipulating the controller ports that are usually used for player input. It is a very simple circuit and is summarised in the following table. Each arrow indicates a direct electrical connection.



** All Arduino pins are connected to ground via separate 30kΩ pull-down resistors . Resistors with a power rating of 0.25W and a tolerance of 5% should suffice for this application. Resistance values between 22kΩ and 100kΩ will suffice for this application.

*** Ground (pin 8) of the DB-9 connector 1 is connected to Arduino ground. 5V (pin 7) of the DB-9 connector 1 is connected to Arduino ground. The Arduino power selection jumper should be set to EXT for the use of an external power source.

**** Ground (pin 8) of the DB-9 connector 2 is connected to Arduino ground.


It should be noted that the ATMega168 microcontroller onboard the Arduino is powered via the outlets on the Vectrex controller. However, the FTDI Serial USB microchip onboard the Arduino is powered via the USB connection to the host computer USB bus. This allows for a reliable transmission of data from the host computer to the Arduino board via the incorporated FTDI microchip. This also allows for direct control of the Vectrex controller ports because the same power bus as the analog to digital circuitry inside the Vectrex powers the micrcontroller that is acting as a control mechanism.



Software Overview: Vectrex Binary
The Vectrex binary acts as a mediator between the bridging hardware and the sound chip of the Vectrex. It is a ROM (read-only memory) image titled VSOUNDER and is essentially a piece of software that the Vectrex console is able to use. The software takes the current state of the two controller ports and uses this state to manipulate the sound chip (programmable sound generator or PSG). The state of the two controller ports thus determines the sounds that the Vectrex creates.

The creation of this binary would not have been possible without the hard work of a number of individuals within the Vectrex community. In particular, the tutorials by both Chris Salomon and Christopher Tumber very were useful as was a triggering code example by Manu Pärssinen . Finally, it is only through the VecFlash hardware developed by Richard Hutchinson that the binary can be currently executed on an actual Vectrex machine (as opposed to an emulator). The source code was assembled in the AS09 assembler. Although a number of variants have been explored thus far, the basic structure and format of the assembly code is as follows.

; pulse wave control example
; by sebastian tomczak
; 26 october 2007
;
; setup bios functions as used in the program
waitrecal equ $f192
byte2sndchip equ $f256
clearsound equ $f272
readbuttons equ $f1ba
; header block
org 0 ; set memory position to zero
fcb $67,$20
fcc "gce 2007" ; copyright year
fcb $80 ; end copyright year string
fdb musa,$f850,$30b8 ; play header music
fcc "vsounder ex" ; program display title
fcb $80,$0 ; end program display title string
; initialise program
jsr readbuttons ; read buttons for initial values
jsr clearsound ; stop any sounds that might be playing
; main program
main jsr waitrecal ; resync
jsr readbuttons ; read buttons into ram
ldb $c80f ; retrieve current button state
andb #$0f ; bitmask least sig four bits
lda #$08 ; modify psg register
jsr byte2sndchip ; set psg register
ldb $c80f ; retrieve current button state
andb #$f0 ; bitmask (most sig four bits revealed)
lda #$00 ; modify psg register
jsr byte2sndchip ; set psg register
lda #01 ; modify psg register
ldb #01 ; data to register
jsr byte2sndchip ; set psg register
lda #$07 ; modify psg register 7 (mixer)
ldb $c807 ; get previous value for psg reg 7
andb #$fe ; turn on tone on voice 1
orb #$08 ; turn off noise on voice 1
jsr byte2sndchip ; set psg register
bra main ; branch back to main loop
musa fdb $fee,$fbe6 ; silent music for header block
fcb $0,$80 ; end silent music for header block
; end

Code 2: The VSOUNDER Source Code

In order to achieve the results heard in the work Extraction Point, a total of five Vectrex binaries were assembled and explored musically via MIDI data from the ProTools environment. Each variant introduced a different set of notes of noise shaping values.



Protocol Overview
The overall structure of the control flow is as follows.

• MIDI data is sent to the Max/MSP patch VECENV
• The Max/MSP patch VECENV generates the pitch and volume data that is sent to the Arduino board
• The Arduino board sets the state of the interfacing hardware that is manipulating the controller ports on the Vectrex
• The VSOUNDER Vectrex binary measures the state of the controller ports on the Vectrex.
• The VSOUNDER Vectrex binary controls the sound chip of the Vectrex as determined by the controller ports

MIDI data is transformed into two four-bit nibbles (see: Software Overview: Host Computer Patch). These two nibbles form a byte as follows.


The high nibble (frequency) corresponds to the controller 2 buttons in the hardware tranfer of data. Button 1 corresponds to bit 4, button 2 corresponds to bit 5, button 3 corresponds to bit 6 and button 4 corresponds to bit 7.

The low nibble (volume) corresponds to the controller 1 buttons in the hardware tranfer of data. Button 1 corresponds to bit 0, button 2 corresponds to bit 1, button 3 corresponds to bit 2 and button 4 corresponds to bit 3.

The state of the controllers is read into a memory location $C80F. The data is represented as follows within this location.

The memory location $C80F is bitmasked† against $0F (00001111) in order to retrieve only the volume nibble. This value is then written to PSG (programmable sound generator) register†† eight. The lower four bits of this register set the volume of the voice one output of the Vectrex.

The memory location $C80F is bitmasked against $F0 (11110000) in order to retrieve only the frequency nibble. This value is then written to PSG register nine. The upper four bits of this register help to determine the frequency which is played by voice one of the Vectrex. Each of the three Vectrex voices can play 4096 different possible pitches. This is controlled by a twelve-bit number held in two registers. For voice one of the PSG, register one is the coarse-tuning register (most significant four bits of the twelve-bit value) and register zero is the fine-tuning register (the eight least significant bits of the twelve-bit value). Acceptable frequency ranges can be achieved by changing the four most significant bits of register zero in tandem with setting certain bits within register one.



Bibliography
Richard Hutchinson. “The VecFlash Multi Cart”. http://www.richard.hutchinson.dsl.pipex.com/new_page_1.htm. (Accessed 28 October 2007).

Manu Pärssinen. “Sound Triggering Example”. http://www.pelikonepeijoonit.net/vec/sound5.as9. (Accessed 28 October 2007).

Kevin Ross. “The Basics – Very Basic Circuits: The Pull-Up Resistor”. http://www.seattlerobotics.org/encoder/mar97/basics.html. (Accessed 28 October 2007).

Chris Salomon. “List of Vectrex ROM Function – Functionally Ordered”. http://playvectrex.com/designit/chrissalo/appendixa.htm#Functionally. (Accessed 28 October 2007).

Chris Salomon. “Vectrex Programming Tutorial”. http://playvectrex.com/designit/chrissalo/toc.htm. (Accessed 28 October 2007).

Christopher Tumber. “Introduction to Vectrex Programming”. http://playvectrex.com/designit/christumber/tutorial.htm. (Accessed 28 October 2007).

"Extraction Point"

"Extraction Point" (featuring Vectrex and Gameboy)
Download it here (3.8MB).

MIDI controlled vectrex: custom volume envelopes

The sound of a Vectrex videogame console is controlled via MIDI information within ProTools.

In this example, a number of custom volume envelopes are used. The MIDI information contains directions as to when the envelope should change its shape.

More coming soon.

Video URL: http://www.youtube.com/watch?v=QfbMPwMZn8w

Tomczak speaks at the postgrad forum

Well, i did my little presentation yesterday at the postgraduate forum. It was received better than anticipated (this is good news).