* updated

rtl/README

@@ -8,14 +8,27 @@ The main makefile is located ABOVE the RTL tree. It uses the FPC
 makefile.fpc to guess reasonable defaults for everything it needs.
 (these files can be found in base.zip on the FTP site)
 
-Some variables that you may want to set (using 'make <variable>="value"') are:
-
-  FPC             - What compiler to use. Use an absolute path.
-                    (default is ppc386)
-  UNITINSTALLDIR  - Where to install the RTL units
-  OPT             - any special options you want to set for the compiler.
+The only variable that you may want to set are
+PP              - What compiler to use. Use an absolute path. 
+                  (default is ppc386)
+UNITINSTALLDIR  - Where to install the RTL units 
+OPT             - any special options you want to set for the compiler.
 
 In principle, you can also descend into the subdirectory of your OS, and
-type 'make' there, that will also compile everything.
+type 'make' there, that should also compile everything.
+
+The tree contains subdirectories for all the supported operating systems,
+as well as all processor architectures. The processor directories contain
+low-level routines which are required for the system unit (if they are not 
+available in high-level language form), as well as optimized versions of
+the pascal generic routines (the generic routine source code is localed in
+the inc subdirectory).
+
+The following directories are not supported officially and may not work
+correctly with FreePascal v1.0:
+
+go32v1 - The DJGPP go32v1 DOS extender (no longer supported)
+palmos - The PalmOS directory for the Dragonball (incomplete)
+
 
 Enjoy.