When does the sign of the target memory location change in a Mix store instruction. For example, suppose register A contains

- 1 2 3 4 5

and memory address 1000 contains

+ 0 0 0 0 0

What is the effect of STA 1000(0:0)? The documentation in "The Art of Computer Programming" says we take the bytes from the right of the register. Are we trying to store +5 into (0:0) of memory address 1000 or -5? i.e. do we get

+ 0 0 0 0 0 or - 0 0 0 0 0?