--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/aud-fcdev3b/README	Sat Oct 09 04:26:59 2021 +0000
@@ -0,0 +1,13 @@
+spkr0 is the new (as of 2021-10) audio mode config for FCDEV3B
+loudspeaker+microphone voice call kit.  The other two configs are historical
+and should no longer be used:
+
+spkrmax config was my (Mother Mychaela's) concoction at the time when I tried
+to use tiny cellphone-sized speakers, which were too quiet in the absence of
+special mechanics and acoustics.  It needs to be noted that setting a positive
+speaker "calibration" gain in the Iota ABB with the volume control set to max
+and with the waveform at full scale produces clipping instead of more Vpp
+output, hence this approach is not really a solution.
+
+mcsi config was an early method of entering MCSI digital voice mode, but this
+method should no longer be used, as it is broken - use AT@VSEL=1 instead.