Update README.md

README.md

@@ -42,9 +42,7 @@ CMake tests are used to confirm a handful of sample programs will run successful
 uVM is a _stack machine_. That is, it gets all of it's arguments from the stack, and returns the result
 of the computation back to the stack when it's done.
 
-There are some exceptions to this. In particular the current version of uvm supports a single variable,
-called `t0`, that can be written to using `xpop0` where x is the datatype of the thing getting taken off
-the stack.
+There are some exceptions to this. In particular the current version of uvm supports registers. 
 
 Additionally the contents of `t0` can be placed on the top of the stack using `xload0`.