detuned notes and the odd tuned frequency. The TIA is not a musical chip unless the composer works within the frequency limits or modulates between two detuned frequencies to create a vibrato tuned note. Audio Control (AUDC0/1) The Audio Control register generates and manipulates a pulse wave to create complex pulses or noise. The following table (with designed duplicates) explains how its tones are generated: References Sources External links ATARI 2600 Programming for Newbies TIA technical information TIA technical manual TIA schematics TIA high resolution die shots Programming the Atari 2600, and Me - Part 1, part 1 of an 8-part series Atari 2600 Development by Joe Decuir Atari 2600 Graphics chips