 Numerous variations of such compilers exist for different environments . For embedded systems , the code may instead be written to another computer , a technique known as cross compilation , over a serial port or even a single TTL bit , while keeping the word names and other non @-@ executing parts of the dictionary in the original compiling computer . The minimum definitions for such a Forth compiler are the words that fetch and store a byte , and the word that commands a Forth word to be executed . Often the most time @-@ consuming part of writing a remote port is constructing the initial program to implement fetch , store and execute , but many modern microprocessors have integrated debugging features ( such as the Motorola CPU32 ) that eliminate this task . 
