Hi,

I've never used that chip (or MC28AD-16) before.
But looking at the datasheets, it should be pretty easy to do with the SHIFTOUT statement.

Maybe something like this un-tested code, which if I got it right, should turn each output on one at a time for 1/2 second each ...
Code:
<font color="#008000"><b>DEFINE </b></font><b>OSC </b><font color="#800000"><b>4

</b></font><font color="#008000"><b>INCLUDE </b></font><font color="#FF0000">&quot;AllDigital.pbp&quot;

</font><b>SClk       </b><font color="#008000"><b>VAR </b></font><b>PORTC</b>.<font color="#800000"><b>3           </b></font><font color="#0000FF"><b><i>; synchronous serial clock pin
</i></b></font><b>SDout      </b><font color="#008000"><b>VAR </b></font><b>PORTC</b>.<font color="#800000"><b>4           </b></font><font color="#0000FF"><b><i>;      &quot;        &quot;    data   &quot;
</i></b></font><b>Strobe     </b><font color="#008000"><b>VAR </b></font><b>PORTC</b>.<font color="#800000"><b>5           </b></font><font color="#0000FF"><b><i>;      &quot;        &quot;    strobe &quot;
</i></b></font><b>OutEnable  </b><font color="#008000"><b>VAR </b></font><b>PORTA</b>.<font color="#800000"><b>4           </b></font><font color="#0000FF"><b><i>;      &quot;        &quot;    output enable

</i></b></font><b>OutData    </b><font color="#008000"><b>VAR WORD              </b></font><font color="#0000FF"><b><i>; 16-bit output state variable
</i></b></font><b>LoopCount  </b><font color="#008000"><b>VAR BYTE

</b></font><font color="#0000FF"><b><i>;----[Initialize the shift register]----------------------------------------
</i></b></font><b>ShiftInit</b>:
    <font color="#008000"><b>HIGH </b></font><b>OutEnable               </b><font color="#0000FF"><b><i>; shift register outputs disabled
    </i></b></font><font color="#008000"><b>LOW  </b></font><b>Strobe                  </b><font color="#0000FF"><b><i>; Strobe idles LOW (active HIGH)
    </i></b></font><b>OutData </b>= <font color="#800000"><b>0            
    </b></font><font color="#008000"><b>GOSUB </b></font><b>SyncSend               </b><font color="#0000FF"><b><i>; clear the shift registers
    </i></b></font><font color="#008000"><b>LOW  </b></font><b>OutEnable               </b><font color="#0000FF"><b><i>; enable shift registers outputs

;----[The Main Loop]--------------------------------------------------------
</i></b></font><b>Main</b>:
    <font color="#008000"><b>FOR </b></font><b>LoopCount </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>to </b></font><font color="#800000"><b>15      </b></font><font color="#0000FF"><b><i>; loop thru all output channels
        </i></b></font><b>OutData </b>= <font color="#008000"><b>DCD </b></font><b>LoopCount  </b><font color="#0000FF"><b><i>;   set a single bit according to LoopCount
        </i></b></font><font color="#008000"><b>GOSUB </b></font><b>SyncSend           </b><font color="#0000FF"><b><i>;   send the data
        </i></b></font><font color="#008000"><b>PAUSE </b></font><font color="#800000"><b>500                </b></font><font color="#0000FF"><b><i>;   wait half a second
    </i></b></font><font color="#008000"><b>NEXT </b></font><b>LoopCount               </b><font color="#0000FF"><b><i>; do next output channel
</i></b></font><font color="#008000"><b>GOTO </b></font><b>Main

</b><font color="#0000FF"><b><i>;----[Send synchronous data]------------------------------------------------
</i></b></font><b>SyncSend</b>:
    <font color="#008000"><b>SHIFTOUT  </b></font><b>SDout</b>, <b>SClk</b>, <font color="#800000"><b>1</b></font>,[<b>OutData</b>\<font color="#800000"><b>16</b></font>]
    <font color="#008000"><b>HIGH </b></font><b>Strobe                  </b><font color="#0000FF"><b><i>; strobe the shift registers latches
    </i></b></font>@ <b>NOP                        </b><font color="#0000FF"><b><i>; hold Strobe for 1uS
    </i></b></font><font color="#008000"><b>LOW </b></font><b>Strobe                   </b><font color="#0000FF"><b><i>; Strobe idles LOW
</i></b></font><font color="#008000"><b>RETURN
</b></font>
HTH,