Hello, This is my first ever attempt at schematic capture and PCB layout.  It would be great if I could get some feedback, critique or any helpful comments about errors, etc.  I'm not sure if I got the grounding right and also not sure if leaving unused pins unconnected is ok (though several threads in the forum seem to say it is). Can the board be made simpler? (only for 8031's).  FYI, I've not built a breadboard version, but the schematics I used for reference look correct on paper. Here's the project: [https://easyeda.com/skip.tavakkolian/8031sbc](https://easyeda.com/skip.tavakkolian/8031sbc) It is not my design; it's actually a modification of the following two designs I found on the net: [https://www.dos4ever.com/8031board/schema.pdf](https://www.dos4ever.com/8031board/schema.pdf) [http://sfprime.net/i8031/8031dip.pdf](http://sfprime.net/i8031/8031dip.pdf) Background: I salvaged a number of 8031's a while back and would like to build a few SBC's with them (primarily to run Forth).  I initially searched EasyEDA hoping somebody had already done it but, as far as I could tell, no one has.  I found the above two designs -- which are fairly similar -- and used them to create the schematic. I used the Auto Router.  I found a couple of EasyEDA tutorials on YouTube that were very helpful (Great Scott was one).  My end goal is to build a few Forth SBC's. Thanks, -Skip