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+# Toshiba T6W28
+
+an enhanced SN76489 derivative. same 4 channels, but with stereo (soft panning!) and noise frequency being fully independent of channel 3's.
+
+this chip was used in Neo Geo Pocket.
+
+# effects
+
+- `20xx`: set noise mode.
+  - 0: thin pulse.
+  - 1: noise.