The notation used for memory resembles arrays in a high level programming language like C. m[3570] means the memory word addressed by 3570. Addresses in the CSC-1 go from 0 up to 4095, since there are 12 bits in addresses. In the RTL statement above, the memory operation is read and the WR wire would be set to low since m[3570] appears on the right hand side of the assignment arrow.

Here is what the STD 2148 instruction would be encoded as:

m[2148] <- A

Since m[2148] is on the left side of the arrow, the memory operation is write and the WR wire would be 1, while MA is set to 1.