rename register to risc

seems to fit the layer much better as we really have a very reduced
instruction set

lib/risc/padding.rb

@@ -0,0 +1,22 @@
+# Helper functions to pad memory.
+#
+# Meory is always in lines, chunks of 8 words / 32 bytes
+module Padding
+
+  # objects only come in lengths of multiple of 8 words / 32 bytes
+  # and there is a "hidden" 1 word that is used for debug/check memory corruption
+  def self.padded( len )
+    a = 32 * (1 + (len + 3)/32 )
+    #puts "#{a} for #{len}"
+    a
+  end
+
+  def self.padded_words( words )
+    padded(words*4) # 4 == word length, a constant waiting for a home
+  end
+
+  def self.padding_for( length )
+    pad = padded(length) - length  # for header, type
+    pad
+  end
+end