diff --git a/doc/7-systems/x1-010.md b/doc/7-systems/x1-010.md
index 94223a2c0..110fed13e 100644
--- a/doc/7-systems/x1-010.md
+++ b/doc/7-systems/x1-010.md
@@ -7,7 +7,9 @@ the sample frequency resolution is pretty bad in the low end though...
 
 even though this chip has stereo output, no board (as far as we know) uses the two outputs that it has... instead, only one output is connected, effectively being used as a mono chip.
 
-the chip also has some (complicated) volume envelope capabilities, with some of its memory being usable for that purpose.
+the chip also has some (complicated) hardware volume envelope capabilities, with half of its memory being usable for that purpose. Volume envelope shape is defined via 4-bit (16 step high), 128 byte waveform.
+
+the chip can store up to 32 nominal sound waveforms and envelope waveforms at once (plz fact check)
 
 this chip was the inspiration for Organya/PxTone (the former being used in a well-known game called Cave Story).