> Please find it attached. The command I'm using is: Thanks Chengyu. The code is very different from what you started the thread with, and seems correct to me: // x19 == n, x21 == next ldr x8, [x21, #8] stp x21, x8, [x19] stlr x19, [x8] str x19, [x21, #8] Can you confirm that this has the same bug when you try to use it? Cheers. Tim.