In lab 7, you need to use an 8 x 1 MUX with a 4-bit counter to transmit a byte across a single wire. You can easily wire this circuit with the 74151 and 74193 chips in your lab kit, as shown in your lab manual.
Simulation is made more complicated by the fact that you do not have models for these 2 chips. So, we'll have to make some!
First, the 74151 MUX. You can do this in one of two ways. One approach would be to simply draw the AND-OR diagram of an 8x1 mux. It's pretty simple, you just need 8 4 input AND's (each of which and's the appropriate input line with the right minterm of the 3 select lines) and an 8-input or function. Hint: Once you place a gate in Digital Works, you can right click on it to increase the number of inputs to 3 or 4.
Another approach would be to take advantage of the 4x1 Mux you made for lab 6. Two 4x1 Muxes can easly be connected to form an 8x1 mux. The circuit diagram below shows you how:
For Additional information on simulating sequential circuits, see Sequential Circuit example and instructions for Digital Works
Good Luck! -Dan