Hard to say offhand, but I would suggest doing a bit of cleanup to make it easier to follow. Rather than physically connecting all the grounds with wires, you can ground various sections on the schematic using the Ground symbol. Same with Vcc to each chip, you can use a Vcc symbol to imply they are all connected together and the software will know to connect the netlist. Also don't forget decoupling capacitors, typically you'll want 100nF between Vcc and ground close to each IC, on the schematic I often draw them all together off to the side but that's a matter of preference.
Have you tried breadboarding the circuit? It's not a bad idea to do that, at least with parts of it. It looks simple enough that you could build it up on a solderless breadboard in a couple of hours.