2600 in 2006 - BTP2 Music Specs (as seen in Stella's Stocking)

RSS Bot · March 10, 2008

In case anyone is curious about the exact specs for the music in Stella's Stocking (BTP2 music driver):

4 independent voices; two are output to each sound channel. The voices are otherwise isomorphic.
Two wave tables, which are used for "loud" and "soft". Normally most voices are shaped to start soft and get loud, or start loud and get soft, or something. In the "Echo Carol" (last tune at fireplace) there's a spot where loud and soft can be heard for a solid stretch.
Five octave range--61 note chromatic from 65.5Hz to 2096Hz (C3 to C8). Notes in the C diatonic scale are well in tune. Some others not so well, but all pitches are recognizable.
Subharmonic distortion only exists at pitches one or two octaves down from the target pitch, not at other pitches (e.g. the C8 has some distortion at 1048Hz, but since that's also a C, it's not particularly objectionable).
All music processing is done by the 6507 processor; it takes 46 cycles every 76 (just over 60%).
No exotic hardware required for the music, though exotic banking may improve the graphics that I can perform while playing the music.
If I get Magic Zeepy banking or some similar scheme working, the EBTBTP2 driver will allow for up to 24 or 32 wave tables instead of two, which should allow for much more varied dynamics and instrumentation. That might be considered 'hardware support' for music, but the CPU would still be doing all the real work.