 After the fetch and store operations are redefined for the code space , the compiler , assembler , etc. are recompiled using the new definitions of fetch and store . This effectively reuses all the code of the compiler and interpreter . Then , the Forth system 's code is compiled , but this version is stored in the buffer . The buffer in memory is written to disk , and ways are provided to load it temporarily into memory for testing . When the new version appears to work , it is written over the previous version . 
