; Hijack the BELL1 monitor routine to do our bidding. ; BELL1 implements the beep sound heard on reset or ; Ctrl-G, etc. It starts with ; LDA #$40 ; JSR WAIT ; delay .1 sec ; followed by code to actually beep the speaker ; In our case, BELL1 always loads the accumulator with ; a fixed number, and executes a 3-byte instruction ; Well, it turns out that to switch banks we need ; 3 bytes, and as luck would have it the other bank ; is empty here. ; So the routine on the other side is the ROM 5X ; dispatcher. It will take what is in the accumulator ; and use that to determine the next action. ; Obviously, $40 should beep the speaker, anything ; else can do whatever we want. .code .org $fbdf sta $c028