Here is a perfectly working 2-byte (8 x 2-bit) memory interfacing circuit.
The keys from top to bottom are:
1) 1 Chip Select switch (ON/OFF),
2) 3 Address bus (A2 A1 A0, in order),
3) 2 Data bus (D1 D0, in order),
4) Read/Write Control, and
5) Clock (Manual Input).
-> Switch ON the topmost key.
-> Select the address (000 to 111).
-> Select Data to write (00 to 11).
-> Turn ON (1) control switch to write.
-> Given a pulse at Clock (0-1-0).
-> Turn OFF (0) control switch to read.
Notice the bulbs or simulation graph (top-to-bottom) which gives the data in that addressed register. Repeat the process from '2nd step' to write data at that or other locations. (No need to further switch OFF the Chip Select.)
