Hello everyone!

Two things:

1) What things do you find important to be included on the silkscreen? EX: Part ID's, polarity checks, etc?

2) I have some left over space for more silkscreen. How could I fill it efficiently? Jumper settings, installation tips, bill of materials, possible confusions and quirks, logos, etc?

Currently I am labeling EACH through hole, polarity checks on diodes, caps, and LED's, putting part ID's and part names next to each component, including a full bill of materials, and explaining a few quirks in my system. I feel like I have a lot of good info there, maybe too much, but if there is something that you find particular helpful, let me know!

I remember watching one of Adrian Black's videos and he said, "The silkscreen is free, just fill it up with stuff!" essentially. So that's what I intend on doing

Thanks for any input!

Chad

I have attached a design I did a few years ago which has some of the densest Silkscreen I've done, might give you some ideas.

One thing I will particularly draw your attention to is the Layer Check box. This allows you to check, at a glance, that each layer has been implemented without any silly mistakes (like the fab getting one of the layers mirrored or something like that). Each number is a layer - silkscreen front, solder mask front, copper front, copper back, soldermask back, silkscreen back. Then the 'C' on the end is all of those on top of each other so you can see if they've been misaligned.

Note: this is not a 6502-design, just an example of what you might want to do with your silkscreen.

_________________
Want to design a PCB for your project? I strongly recommend KiCad. Its free, its multiplatform, and its easy to learn!
Also, I maintain KiCad libraries of Retro Computing and Arduino components you might find useful.

I don't bother with things that aren't useful, as it takes too much time to decide what to write! Also my layouts have tended to be quite cramped, as I'm trying to reduce board size/cost, so there's no room for more than just an ID next to each component. Maybe when the design is working well it's worth adding more in future revisions though.

I do put a github link, version number, and issue number (in case there are minor revisions or bugfixes that aren't substantially different). The notion is that the software/firmware corresponds to the version number, and supports all issues of that version number; but version number changes are less compatible and may require radically different software.

Anything user-facing needs labeling too - jumper positions and what they do, test points, connector pins. When you need to debug something it's good to know easily which pin is which!

Regarding test points, it's a separate issue but having a decent grounded test point is very helpful for clipping oscilloscope probes to, and if you anticipate having to debug something a lot then adding a single connector with the relevant pins on it makes it very easy to plug and unplug the debugger. In this regard with the 6502 if you supply the data bus, clock, and ground, that's enough to run hoglet's logic analyser, so if you put them all in a line you can make a combined plug for all those signals and easily plug it and unplug it - I'm planning to do this for a board I'm iterating on at the moment, and labeling these pins for clarity in case I also want to probe them directly. Possibly including SYNC and RWB as well as that helps the protocol decoder a bit.

> I do put a github link, version number, and issue number

Excellent idea!

Anime and memes. Nuff said

I try and put enough information onto the silkscreen so that I don't have to refer back to the schematic when soldering. The complete part number for large ICs and 'obvious' detail for smaller things like caps, resistors and TSSOP-5s etc...

Also memes!

IF you should chance to come across my cat feeder, and just happen to pull the processor board out, you will find inscribed thereon "My name is Ozymandias, King of Kings: Look upon my works, oh ye mighty, and despair!"

Seemed like a good idea at the time, and the boss liked it

Neil

Well, since y'all are posting pictures, I'll do likewise. I know mine is blurry, but the idea is there: I'm trying to fill up the whole back side of the board with text.

These are good suggestions! I like putting those part names on there as well, I won't go without them! Github link was a great idea, I just put that on there. Anime for sure

Alarm Siren, how do you make your projects Open Source Hardware? Is there anything to it besides just slapping a label on it? I put on my board and in my code "public domain". I'm a picky guy and CC3 is just not enough for me, I go all the way

Thanks everyone, any other ideas are welcome.

Chad

I'm impressed by the low via density on your Acolyte board, Chad! I struggle with placing part numbers and other information such that it won't get swiss cheesed.

The pin names on the reverse side should be great for debugging or other feature hacking. Along with that memory map info and parts list.

Thank you Clyde. I actually did each of those traces by hand. I had auto-router do it's thing, and I was dissatisfied with how it ran traces in weird places to just save a single via. So I started over completely, first with address and data lines, and worked out from there. It was a 3 day process, many hours, but definitely paid off. I got only a few more vias than the auto-router in the end, but at least I won't have the clock line running silly all over the board now.

Thank you, I appreciate the comment.

Chad

If you want to go down the public domain route, I direct you to the CC0 license. This is superior to simply stating that you put it in the public domain, because in many jurisdictions that isn't actually something you can do. The CC0 license works by putting it in the public domain if possible, but if not offers a license to the user that grants effectively the same rights as being in public domain. It also disclaims warranties and thus gives you some measure of protection against potential disgruntled users.

For the actual PCB, if you're using KiCad, it has suitable silkscreen symbols built-in. You can go to the "Symbol" library and find them in there. As you have lots of space and want to go public domain, I would recommend the "Symbol_CreativeCommonsPublicDomain_SilkScreenTop_Small" symbol. The "Open Source Hardware" symbols are also in there, in a variety of sizes. As you want it to be open source then a github link (or equivalent) is obviously also a must, otherwise how will they find the source files?

In the actual repository, you'll want to do two things: 1. add a note in the README file that states you're putting it out under CC0 and link to the CC0 license. 2. add a LICENSE file which contains a copy of the full legal text of the CC0 license. The former makes it easy for users of your repository to see the license at a glance, the latter triggers a thing in GitHub so it knows what license you've used and can categorise your repository appropriately. As an example, you can see I've done both (though for a different CC license) in this repository of mine.

However, a word of caution first: putting out under the CC0/Public Domain really does mean you lose all control over it, forever. Users of your work don't even have to credit you. If you're OK with that then go for it, but personally I usually use CC-BY-SA. That way at least my original work gets some exposure via attribution, and users of derived works are guaranteed the same rights.

_________________
Want to design a PCB for your project? I strongly recommend KiCad. Its free, its multiplatform, and its easy to learn!
Also, I maintain KiCad libraries of Retro Computing and Arduino components you might find useful.

I will have to think about this. I'm happy that "creative commons" does stuff like this, but I'm even opposed to organizations making claims one way or the other. I have extremely radical views on copyright/licensing.



I haven't put the "open hardware" logo on there because I don't want it to be attached to yet another license of some kind. It most certainly is open! But I just don't know enough about it yet, will be reading more soon.

As for that particular logo, it looks really crummy, so I found a "public domain" logo from Wikipedia and slapped it on there just now.



Thank you for the word of caution. I really really do not like attribution requirements at all. Again, I'm super extreme, I admit it. I will generally/always give credit to whoever created the public domain stuff in the first place, but I do that because I appreciate their putting it in the public domain in the first place.

I put my name, the year, and "public domain" in ASCII in my ROM code as well just now. Might as well. I plan on putting all of this on github eventually when I finally decide to get it printed.

Thank you for the info. I'll be thinking it over a bit more, particularly the CC0 stuff.

Chad

The Open Source Hardware logo doesn't apply a license of its own. You're allowed to use it if the license you choose meets the minimum requirements of the OSHA, which putting it into public domain/CC0 certainly would.



You're entitled to your views and I respect them - I have no especial love for the modern copyright regime - but I would strongly advise you to make use of the CC0 if your intent is to put it in the public domain, because just saying you're putting it in the public domain doesn't actually work in some jurisdictions, or can be ambiguous about which rights, exactly, you're disclaiming. The CC0 handles these complexities for you.



Well, the CC0 logo I suggested would only be appropriate if you ultimately decide to use the CC0 anyway. Also, silly question perhaps, but what license is the public domain logo you found released under? It would make sense if it is itself public domain, but most things on Wikipedia are CC-BY or CC-BY-SA, hence the concern...

_________________
Want to design a PCB for your project? I strongly recommend KiCad. Its free, its multiplatform, and its easy to learn!
Also, I maintain KiCad libraries of Retro Computing and Arduino components you might find useful.

Oh, the CC0 logo, yeah that one looks good. The public domain one was like some weird line-art to make it looks like a zero.

Wikipedia had that particular public domain logo, which they said, "it itself is in the public domain". Kind of funny, it would be ironic otherwise

I will consider the CC0 stuff, thank you.

Chad

With apologies for the advertising (hard to see without it!) here's my favourite PCB design ever:
- two vias
- two components
- no battery
- costs only pence
- credit card sized
It lights up in the presence of low frequency RFID signals; the company gives 'em away at trade shows or to help customers check their equipment but I basically designed it so we could see where the fields were around test kit in the lab.

Neil