This is a redesign of the Apple II Pi (http://schmenk.is-a-geek.com/wordpress/?cat=10), with the following goals:
- Keep the design in files with an open format, editable with freely-available design software.
- Replace through-hole components with surface-mount components to the extent that it's possible to do so.
- Enable future improvements to the design by anybody interested in doing so (item 1 helps considerably with this).
Recent discussion in comp.sys.apple2 (https://groups.google.com/forum/#!topic/comp.sys.apple2/ogb335ww8-w) has already led to one change: provision has been made to clock the 6551 with either a crystal (and, if needed, an extra capacitor) or the GPIO4 line from the Raspberry Pi. Also, I had originally planned on using the WDC W65C51N in the LQFP-32 package, but (1) the current datasheet indicates that part might not be widely available and (2) there are some bugs in the W65C51N that indicate it might be a better idea to use new-old-stock 6551s from other suppliers. That is why the 6551 is still using the old DIP-28 footprint.
This design depends on symbols and footprints I have modified and/or created. You'll want to check out these companion repositories and make sure they're where your gschem and pcb can see them: