diff --git a/papers/doc/7-systems/bubblesystem.md b/papers/doc/7-systems/bubblesystem.md
index 0c363163..7b14e90e 100644
--- a/papers/doc/7-systems/bubblesystem.md
+++ b/papers/doc/7-systems/bubblesystem.md
@@ -1,14 +1,12 @@
 # Bubble System WSG
 
-a Konami's 2 channel wavetable sound generator logic used at their arcade hardware Bubble System.
+a Konami-made 2 channel wavetable sound generator logic used on the Bubble System arcade board, configured with K005289, a 4-bit PROM and DAC.
 
-It's configured with K005289, 4 bit PROM and DAC.
+however, the K005289 is just part of the logic used for pitch and wavetable ROM address.
+waveform select and volume control are tied with single AY-3-8910 IO for both channels.
+another AY-3-8910 IO is used for reading sound hardware status.
 
-Also known as K005289, but that's just part of the logic used for pitch and wavetable ROM address.
-Waveform select and Volume control are tied with single AY-3-8910 IO for both channels.
-Another AY-3-8910 IO is used for reading sound hardware status.
-
-Furnace emulates this configurations as single system, waveform format is 15 level and 32 width.
+Furnace emulates this configuration as single system with 32x16 wavetables.
 
 # effects
 
diff --git a/papers/doc/7-systems/segapcm.md b/papers/doc/7-systems/segapcm.md
index 1b3ed63f..36462633 100644
--- a/papers/doc/7-systems/segapcm.md
+++ b/papers/doc/7-systems/segapcm.md
@@ -4,7 +4,7 @@
 
 yep, that's right! 16 channels of PCM!
 
-a chip used in the Sega OutRun/X/Y arcade boards. eventually the MultiPCM surpassed it with 24 channels, and later they joined the software mixing gang.
+a chip used in the Sega OutRun/X/Y arcade boards. eventually the MultiPCM surpassed it with 28 channels, and later they joined the software mixing gang.
 
 # effects
 - `20xx`: set PCM frequency.