Portfolio Noah Vawter: TIA Sequencer
by Noah Vawter
TIA is the multimedia chip inside the Atari VCS/2600. The sounds
and music it can make are very attractive to me for two reasons.
Firstly, it is an engineering masterpiece, demonstrating how to get
the most flexible sound with
very few resources. Second, since
so many people my age played Atari, recognize these sounds and
enjoy them, a wide opportunity for
nostalgia exists. Now,
with a sophisticated controller attached to a laptop simulation of this
delightful chip, I can make high quality music.
(Move your mouse over the picture to see it next to my drum machine.)
I wrote this software in my spare time on public transportation.
I use it to write patterns of notes, waveform changes and volume tracks.
Then, I sequence the patterns together to form songs, sometimes
coordinating with other electronic instruments, especially drum machines.
Although there is no MIDI Sync, I took extra time to ensure that
the sequencer timing is accurate. It loses only 1/96th of a beat in
Sequencer User Interface
I always feel very lucky when I write a sequencer, because I
write snappy user interfaces with flexible and innovative
options. TIAseq is based on tracker interfaces, which means
emphasis on the cursor keys for flitting about and
number keys for entering notes. There is also
ample support for editing functions like insert, delete,
home end, etc. And of course you can edit patterns
will they're playing.
The patterns themselves are innovative and flexible, because
there are actually 6 tracks, three tracks per voice. Each
voice has an independent track for note, waveform and volume.
In addition to looping and ping-pong modes, each track can
have its own tempo. The benefit is that
polyrhthmic effects can be composed. For example, one can very
easily beat a three note arpeggiated chord against a
four-step waveform sequence with any ratio of periods.