--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/Modem-operation	Sun Oct 18 18:08:15 2020 +0000
@@ -0,0 +1,16 @@
+FC Tourmaline stdmodem functional configuration is equivalent to Magnetite
+hybrid.  The only intentional diff from Magnetite to Tourmaline in the modem
+configuration is the change of Nucleus: Magnetite uses the blob version of
+Nucleus which came with TCS211-20070608, whereas Tourmaline uses the source
+version of Nucleus by Comrade XVilka.  It is essentially a change from an
+unknown version of Nucleus to a known one, thus it should generally be
+considered an improvement - but as always with such changes, extensive
+verification and testing needs to be done in order to ensure that nothing got
+broken.
+
+Aside from the one intentional change of Nucleus version, FC Tourmaline is an
+entirely new firmware source tree, thus it is always possible that something
+could have got broken unintentionally, particularly in rarely-tested areas of
+the firmware.  Therefore, extensive testing will need to be done before we can
+declare Tourmaline stdmodem as officially replacing Magnetite hybrid for stable
+modem products.