little-scale — Overclocked Game Boy (2008)

Four lines and three audio clips, but they close a question the 2009 underclocking posts left open and they attribute the ProSound mod.

Key claims#

• The machine: "Overclocked to 8MHz instead of 4.19MHz (i.e. almost twice the speed, almost twice the pitch)", a green power LED, "Internal, post-potentiometer ProSound using the headphone jack", and the speaker removed.
• Clock speed changes are again credited to Gieskes' underclocking/overclocking tutorial — the same page cited a year later for the 2 MHz mod (s-little-scale-underclocking-and-retuning).
• ProSound attribution: "The ProSound modification was invented by Timothy Lamb (Trash80). I believe that Nanogrrl was the first person to use the ProSound modification on an old grey Game Boy, but I could be mistaken." Documentation at littlesounddj.com/lsd/prosound/.
• Three recordings of the same riff — unmodified, ProSound, and ProSound + overclocked — are offered as the comparison (audio only; not fetched).

Practical takeaways#

• 8 MHz is the mirror of the 2 MHz underclock: the clock roughly doubles, so pitch and tempo roughly double. 8.000000 ÷ 4.194304 = 1.9073, which is an octave minus 82 cents — the same 82-cent error as the 2 MHz crystal, in the other direction. A retuned ROM fixes it the same way, by computing the pitch table for half the fitted crystal (rom-retuning).
• Post-potentiometer ProSound taps the signal after the volume wheel, so the knob still works; the speaker comes out because it is fed from the same amplifier.

Relevance to the wiki#

Answers a To verify on s-little-scale-underclocking-and-retuning: asked in 2009 whether his replacement pitch table would work for an 8 MHz crystal, little-scale said "in theory… because I haven't actually tried it out with an overclocked GB". He had in fact built an 8 MHz machine a year earlier — the post says nothing about retuning it, so the table question stays open, but the overclock itself is documented and its pitch effect stated.

To verify#

• He does not say what crystal value he fitted (8.000000 MHz is assumed from "8MHz"), nor whether the machine was reliable at that speed.
• The exact interval an 8 MHz machine plays is computed here from the ratio, not stated by him — he says only "almost twice the pitch".
• The ProSound attribution to Trash80, and Nanogrrl as first on a DMG, are his own recollection and he flags the second himself ("but I could be mistaken").

Pages touched#

game-boy · rom-retuning · alternative-tunings · recording-samples · little-scale