Talking of interesting phenomena, I also have one: #define ALU(m,i) ld a,(m) \ i \ ld (m),a This is a funny macro: TASM can handle it, but AS cannot. The problems arise when I use it a bit "advanced" way, e. g. ALU(MyVar,inc a \ inc a) Also, if a macro is embedded in another macro, it is thrown back with an "unrecognized instruction" error. PG