Indirect Data Reference
Instructions tell where the data is, not
what the data is … contents change
One instruction has many effects
   ADDB 10, 16, 20
10
11
12
13
14
15
16
17
18
19
20
21
8
 7
15
...
10
11
12
13
14
15
16
17
18
19
20
21
60
-55
5
...