Sellam, Just from looking at the disassembly you provided, it appears that the & command will pass control to address $03F5, which is a three-byte space expected to contain a JMP instruction to a handler. The jump to $03F5 is done in such a way that when the handler is reached the accumulator will contain the character in the BASIC program text immediately following the &. On return, BASIC parses the next statement beginning at TXTPTR. It stands to reason, then, that your "&" handling routine needs to advance TXTPTR by calling CHRGET until an end-of-statement is reached. So the basic (no pun intended) rules of engagement seem to be: load your handler's code into memory, poke a $4C (JMP) into $03F5, and your handler's entrypoint address into $03F6 and 7. The simplest handler should make sure that the character in the accumulator is an end-of-statement (colon character, or end of line $00 I believe) when called (perhaps JMP to SYNERR if not, or just ignore). If you parse, or decide to just ignore whatever follows the "&", make sure you call CHRGET ($00B1) until you get an end-of-statement, so BASIC is armed to parse the next command in the text when you return. You could also just set Y to the number of characters you wish to ignore and jump to ADDON ($D998). Anyway, that's all from a quick code review. In practice, I'm sure I've missed some details, but maybe that will get you rolling in the right direction. I'm sure more Apple-knowledgable folks will chime in, too. Handy that the implementation not only gave you a jump vector, but also provided enough context to allow you to parse whatever followed. I remember using some DOS extensions that let you do things like &COPY "fromfile","tofile". I wished for that on the PET many times (wouldn't that have made for nicer disk handling than that OPEN 15,8,15 mumble?). Patrick