Step 4: About the Parts
I'm looking at my schematic now and I'm noticing I left a lot of values out, and some are just out and out wrong. Most notably the buffer ICs themselves. In order to get the kind of performance I have been talking about 74LS245s cannot be used in this circuit. You have to get the AHCT family IC. So that'd make IC1 and IC3 74AHCT245 s
Why I left values out or just have them plain wrong in my schematic is a combination of reasons ranging from it was easier to do, to the diagram would have just been too busy had I included them. So I'll put a partial parts list here to make up for it.
RLED1 &2 330
RFD1 RFD2 4K7
RN1 RN2 100K
Again the 74LS245N is really a 74AHCT245N I also used a different optoisolator but the pinout was the same as the quad opto in the schematic. I used an NTE3221 because I had one lying around. It is a lot of work to make new library elements so I use what is there when I can. That is why the numbers don't always agree. If I can find a device that is close enough physically I use it. You can too.
Here is my Eagle board file.