move .macro src,dst,len
if src != dst
 if src ?> dst
  ld hl,src
  ld de,dst
  ld bc,len
  ldir
 else
  ld hl,src+len-1
  ld de,dst+len-1
  ld bc,len
  lddr
 endif
endif
.endm

move $100,$200,$300
move $200,$100,$300
move $100,$100,$300