--- a/README	Sat May 16 07:27:31 2020 +0000
+++ b/README	Sat May 16 18:44:01 2020 +0000
@@ -74,8 +74,14 @@
 * ffsagent-fcfam-{irda,modem}.srec version is built with the CONFIG_TARGET_FCFAM
   version of the dev.c table, appropriate for FCDEV3B.
 
-* ffsagent-ti26-{irda,modem}.srec version is built with TI/OM's original version
-  of the dev.c table, appropriate for Tango/Caramel/Luna and for Openmoko GTA0x.
+* ffsagent-ti26-{irda,modem}.srec version is built with TI's original version
+  of the dev.c table with minor additions by OM and FC, appropriate for
+  Tango/Caramel/Luna, for Openmoko GTA0x and for GTM900 modems converted to FC.
+
+  Target name ti26 refers to 26 MHz CLKTCXO input to Calypso, i.e., *not*
+  D-Sample - see below.  If we ever get our hands on a D-Sample C035 board or
+  some other platform with similar needs, it will be easy to create a ti13
+  counterpart.
 
 * compal and pirelli versions correspond to FreeCalypso aftermarket FFS configs
   on those targets, *NOT* Compal's or Pirelli's original FFS!
@@ -86,7 +92,19 @@
 Back in 2015 I (Mother Mychaela) made the decision to define FC aftermarket FFS
 on Mot C139 phones as 64x3 (meaning 3 sectors of 64 KiB each), located at
 0x3C0000.  Right now I am thinking that we should change to a larger FFS config,
-but I have not yet committed on any specific new config.  When and if I make
+but I have not yet committed to any specific new config.  When and if I make
 the big switch, compal-new will be the new config, while compal-old will remain
 the original 2015 config.  At the present moment the two ffsagent-compal-*
 images are identical.
+
+No Calypso C05 target support
+=============================
+
+The present FFS editor application is a stripped-down derivative of FC Selenite
+firmware, still containing Nucleus RTOS, thus it uses interrupts.  Having a
+run-from-RAM (or more precisely, independent of flashed fw) application use
+interrupts requires having Calypso boot ROM version 0300, which is present only
+in Calypso C035 silicon.  (We can still use this ROM for our purpose of
+interrupt redirection even if it is disabled on boot like on Compal phones.)
+Because of this interrupt handling issue, this FFS editor application is not
+available on the Mother's D-Sample C05 board, or any other Calypso C05 target.