Very cool! And bravo for making this open source

Awesome, thanks. They tag you a bit on shipping, but the cost is still under $2.50 a board.

Applauding you for doing this and keeping it open source!

That's a nice free gesture. I thought of creating some DIP adapter nvram boards and putting them out for free a few years back, but I'm pretty unclear of how support and liability would work on open sourced designs in general. I figured regardless if you offer something for FREE or $100.. if it can be tied back to you, it increases your exposure since you were the person that put it out there. Not really a settling thought to me, so I never went down that free path heavily. There's simple diagnostic tools I'd have put out for free otherwise. It's all exposure though if people misuse the stuff, at least that's how I see it.

Maybe open source hardware doesn't work that way. But take a more extreme example of a design that works with mains voltage & makes it easier for someone to injure themselves or their property -- and it can be tied back to the designer. I'd think there'd be some liability concern there.

Just some thoughts I've had a long the way. Kudos for offering something up for free like this, hopefully you don't find the support or liability aspect to be an issue. As I said, I really don't have a clear idea of either -- just assumptions. Uncharted territory for me and I'll probably keep it that way.

Well good luck It's nice to have other DIY options out there for sure.

For people building these boards, better to get the "2.54 round machine pin male headers" than use 2.54 square pin headers. The square pins will be harder to insert into the socket & stretch the IC socket contacts out to the point a normal DIP chip would then just fall out. The round pin headers are much thinner in diameter.

Just a suggestion, I'd keep the copper fills away from the through-hole pads a bit more.. or not have them running between pads at all. They look very close to pads, even at pin #28 for the +5V to the RAMTRON. A small scrape on the filled zone could easily then cause a short to GND (top-side). Assuming there's a fill on the bottom side, same issue.

IMHO copper fills seem like a great idea, but I've seen them cause problems. One case was a small regulator that had a fill near the mounting screw-hole.. and star washer bit into the filled area, along with a nearby trace & created a short.

I use copper planes ("fills" or "pours" depending on specific software being used) for all boards. They greatly improve connectivity to signals connected to the planes (usually ground) and can work great as a 'built in heatsink' for certain parts. However, their spacing does look pretty small on this board. Appears to be in <10mil and maybe about 6mil spacing for that one. For the issue with the star washer hitting into the plane - that was somebody's design or implementation flaw. The pad should have been larger or the star washer should have been smaller or an insulator (e.g. mica insulating washer) should have been added.

The only thing I would recommend on this one --> square 0.025" posts are not great for mounting this sort of thing. If you don't think so - ask ANYBODY that has worked on a Gottlieb System 80B CPU board. Use round 0.019 pin strips and plug these into standard DIP sockets. Costs a bit more but very well worth it.

Finally put one of these together and put it in my Fire!, works great. Thanks @lyonsden!

All of my parts finally arrived. I assembled and installed in my #F-14 Tomcat. Everything works perfectly. Thanks Professor!

Bump.