Now let's look at indirect addressing in the CSC-1 in some detail. The two instructions that implement indirect addressing are

LDS   -- load from memory using the Secondary register's
         contents as the address; put value into A

STS   -- store A's value into memory using the Secondary
         register's contents as the address

This section will lead you through the details of how the LDS and STS instructions work, using the CSC-1 block diagram repeatedly, as was done in Section 7.6.