Added comment

tools/modelsim/run_modelsim

@@ -46,5 +46,14 @@ else
   exit 1
 fi
 
+# Remarks:
+# - No need for MODELSIM_TCL environment variable and modelsim.tcl, because these are not preferred and instead call commands.do via -do argument.
+# - No need for MODELSIM environment variable to point to a specific modelsim.ini file, because RADIOHDL can use the default modelsim.ini
+# - For RADIOHDL the modelsim project files are created by a Python script.
+# - The paths to the IEEE libraries are defined by the MODELTECH environment variable that gets defined by Modelsim itself when it starts
+# - The paths to the FPGA technology libraries are defined in the [library] section in the modelsim project files using MODEL_TECH_ALTERA_LIB
+#   environment variable that gets defined in quartus_version.sh. Similar paths to generic libraries are defined using their absolute path.
+# - Default modelsim.ini settings can be overruled by project specific settings in the [vsim] section in the modelsim project files.
+
 # Start the Modelsim GUI
 $MODEL_TECH_DIR/linux_x86_64/vsim -do ${RADIOHDL}/tools/modelsim/commands.do

tools/quartus/quartus_generic.sh

@@ -25,7 +25,7 @@ if [ -z "${QUARTUS_GENERIC_SH}" ]; then
 export QUARTUS_GENERIC_SH=true
 echo "Run quartus_generic.sh"
 
-# Derive generic Quartus tool version related paths from $QUARTUS_DIR
+# Derive generic Quartus tool version related paths from $QUARTUS_DIR that gets defined in quartus_version.sh
 # Quartus, SOPC, Nios
 export QUARTUS_ROOTDIR=${QUARTUS_DIR}/quartus
 export QUARTUS_ROOTDIR_OVERRIDE=${QUARTUS_DIR}/quartus