Here is a schematic I made for an 8 step 4 channel programmable step sequencer for a Make magazine tutorial. I've been waiting till the article is done to post the schematic but it's taking longer than expected soooooo..... here it is now.
<a href="http://casperelectronics.com/wp-content/uploads/casper/Sequencer-schematic.jpg"><img src="http://casperelectronics.com/wp-content/uploads/casper/Sequencer-schematic-767x1024.jpg" alt="" title="Programmable step sequencer" width="400" height="570" class="alignnone size-medium wp-image-793" /></a>