LittleSoundDj: Microtuning How To ...

from an 8bc post by abrasive:

Idle thought: can LSDJ be retuned to non-standard tunings?
Cue a few minutes in a hex editor and half an hour in Perl...
the result: an LSDJ tuning script.

The script takes an LSDJ ROM, and rewrites the tuning table (and optionally the note names) into a new copy of the ROM. Frequencies can be manually specified (all 108 notes), or generated in equal temperament, cent steps, cent series or ratio series.

The latest version of the script (works with LSDJ 3.9.9) can be found at
http://bur.st/~abrasive/lsdj_tune/

Some examples:
24-tone equal temperament
lsdj_tune --et 24 --base A5 440 --rom lsdj.gb --out lsdj_et24.gb

12-tone ET, manually
lsdj_tune --cents 0,100,200,300,400,500,600,700,800,900,1000,1200 --base A5 440 --rom lsdj.gb --out lsdj_et12.gb

Wendy Carlos' alpha scale
lsdj_tune --cstep 78 --base 0 70 --rom lsdj.gb --out lsdj_alpha.gb

Pythagorean 13-tone
lsdj_tune --ratio 1,256/243,9/8,32/27,81/64,4/3,729/512,1024/729,3/2,128/81,27/16,16/9,243/128,2 --names D,Eb,E,F,F#,G,G#,Ab,A,Bb,B,C,C# --base 0 73.42 --rom lsdj.gb --out lsdj_pyth.gb

Current limitations (1.3):
Base frequency specification is a bit dumb – it won't take custom note names, and sequences (--cents, --ratio) always start on the base note.