codong RegisterSlot with reg and slot

lib/risc/instructions/reg_to_slot.rb

@@ -5,7 +5,7 @@ module Risc
   # Both use a base memory (a register)
 
   # This is because that is what cpu's can do. In programming terms this would be accessing
-  #  an element in an array, in the case of RegToSlot setting the register in the array.
+  # an element in an array, in the case of RegToSlot setting the register in the array.
 
   # btw: to move data between registers, use Transfer
 
@@ -16,6 +16,8 @@ module Risc
   # Produce a RegToSlot instruction.
   # From and to are registers
   # index may be a Symbol in which case is resolves with resolve_index.
+  #
+  # The slot is ultimately a memory location, so no new register is created
   def self.reg_to_slot( source , from , to , index )
     raise "Not register #{to}" unless RegisterValue.look_like_reg(to)
     index = to.resolve_index(index) if index.is_a?(Symbol)

lib/risc/instructions/slot_to_reg.rb

@@ -14,8 +14,9 @@ module Risc
   end
 
   # Produce a SlotToReg instruction.
-  # Array and to are registers
+  # Array is a register
   # index may be a Symbol in which case is resolves with resolve_index.
+  # a new regsister will be created as the result, ie the reg part for slot_to_reg
   def self.slot_to_reg( source , array , index )
     raise "Register #{array}" if RegisterValue.look_like_reg(array.symbol)
     index = array.resolve_index(index) if index.is_a?(Symbol)