So last week Lauren and I played at the fifth concert of the Tyndall Assembly series. There were not that many people there when we played- which is unfortunate (for those that weren't there ;). We played two pieces: Black Dog White Dog and Toriton (for one).
You can watch a one minute video containing excerpts from the performance here (mov, 1.2mb). If you are unable to watch it, please let me know and I will convert it to a more friendly format. It is just the same feed as was shown on the TV and the projector, so it is not 'the whole performance' on one screen. Or something.
The idea behind Black Dog White Dog is to have a 'visual score' written on the Vectrex Logo program. The score is comprised of three movements, held in banks 1-3 of the Vec. The Vectrex is then filmed via a video camera, which is on its side to compensate for the machine's unique screen dimensions. The video signal from the camera is then routed to a 51cm TV. The output from the TV was further routed to a projector, so the audience could properly see the Vect animations.
Connected to the TV was a set of twenty-four light dependent resistors (whose resistance lowers the more light is presented to them), each replacing certain buttons in one of four 'recreated' Atari 2600 CX50 control pads. These four matrix sets where plugged into two Atari 2600's each running a copy of Paul Slocum's Synthcart. The catch is that the LDR's are not the standard, cheap 10MΩ or even 1MΩ types. Those cheaper ones could not lower their resistance enough to allow notes on the Synthcarts to trigger. After a quick test, I realised roughly 3-4KΩ is required for the task; however, the 1MΩ model only goes as low as 6-7KΩ when the television is at it's very brightest. In the end, I ordered 0.5MΩ models from interstate. They work very quickly and very well, however the TV must be calibrated properly in terms of having the correct brightness and contrast.
Below you can see the layout of the four pads.
Left Atari Right Atari
Button Pad A Pad B Pad C Pad D
1 X X X
3 X X
4 X X X
5 X X X
7 X X
8 X X X
* X X
0 X X
Both Ataris' visuals where routed to two 34cm TV, and the Synthcart was set to lightshow mode, a simple (yet effective and very cool looking) visualisation based on the notes that each 2600 is playing. Both Ataris had had a direct audio modification performed on them. The audio from the left Atari was played directly through a Marshall guitar amp. The right Atari was through a Behringer bass amp. Both Ataris were set to square and lead voicing.
Here you can view the Logo patches for the three movements.
Below is a picture of me playing the piece for water surface, Toriton (for one).