Cartridge ports and other pin adapters?


#1

Probably a question that has risen it’s ugly head before, but I have not been fortunate enough to come across anything that makes sense to me because I’m apparently not very bright.

I’ve been able to find the CONN_ pinouts just fine, but that doesn’t exactly help me with what I need. Let’s say for instance, I’m trying to make an adapter that plugs directly in to the serial port of a Sega Dreamcast. Or, for that matter, maybe a game cartridge for an Atari 800. Or a PCIE card.

All the CONN_ connectors I’ve seen listed are all through-hole pads for pins. Am I missing something?

I understand the Dreamcast Serial port is a non-standard 10-pin (0.5mm???) port and that’s not likely to be something included right off the bat. But, something like a PCIE card or an ISA bus should be doable? Right?

I’m sure my inexperience isn’t helping here and I’m probably not looking in the right place or I’m unfamiliar with the nomenclature, but is this the kind of thing I have to do manually?


#2

The CONN_ symbols have footprint filters activated. (These filters are set such that they show only pin headers. I will ask the library maintainers if we should change that. Edit: i created an issue over at the github repo)
When using cvpcb to assign a footprint you need to set the filters accordingly. (use filter by “number of pins”[blue] only instead of by “symbol defined filter”[magenta]; [color]: the color i used to mark the buttons in my screenshot.)

You could also reduce the results further by selecting a Connectors_ library in the leftmost column and activate the filter by library option.

To be honest i’m not sure if the footprint you need is already in the library. It might be necessary to design the footprint yourself. (If you do that it might be nice if you could add it to the kicad library. Have a look at the KLC and FAQ before starting. Without more details i don’t know which library would be the correct one.)


#3

There are stock footprints for PCI, ISA etc. Obviously game cartridges are highly specific and unlikely to be there, unless they happen to use a common footprint.
You mentioned 5 different connectors seemingly randomly, I can’t see a pattern. A good place to start is “Connectors”. A handy tip is turn on footprint view, then you can just zip through with arrow down key until you find something.


#4

Ah, yes, I can see where the disconnect is there. I think I was aiming more for a theme. I do a lot of retro gaming repairs and modifications, and so, rather than solder wires directly to the board of, let’s say an Xbox or a Playstation 2, I’d rather make a board that plugs directly in to whatever ports are already available on these, or even PC type connectors. If that makes more sense?

I figured it this way, many of these ports are more or less standard pin widths and depths. I used the Dreamcast Serial adapter as a good example because it’s a straight 10-pin, single sided connector that I should be able to plug a PCB directly in to given the pads match up. Honestly, I still don’t know if I’m making any sense here, but I hope that’s a little more clear?

Thank you, by the by, for the information. It is greatly appreciated!


#5

facepalm You know… This is one of those occasions where RTFM really applies. I was not aware of the defaults, as you pointed out. Something I probably should have investigated more thoroughly. The information you have provided to me is, nonetheless, extremely appreciated and invaluable.

Once I start creating new footprints, I’ll gladly upload them to wherever they need to go. I’m sure I’m not the only one doing what I’m doing and they’d be helpful to retro gaming mod designers in the future. I hope. Maybe? Or possibly I’m just deranged and in need of some form of prolonged therapy.


#6

I’m sure others might appreciate if this footprints are in the library. Just be warned. We are quite strict when it comes to accepting footprints, symbols or 3d models in the library.
Be sure you read the KLC and maybe ask if you do not understand something. You can ask in this forum or you could create an issue over at the github repo for the kicad library. Or worst case: create a pull request and just fix any issues that arise with it.

We get a question related to misunderstanding cvpcb at least once a month here, so don’t feel bad about it you are not alone. (Why do you think i have a screenshot prepared?)

You got me thinking about the footprint filter settings for the conn_ symbols. If we find a way to make them better this might help other users. (So you are already contributing to making the library better ;))


#7

Ok, I see the link now. Connectors like this
https://www.surplussales.com/Images/ComputerAccess/EdgeConnectors/CPC-225-21521-404-117_lg.jpg
where the mating half is a PCB edge. These connectors have inward facing terminals, and are designed so a typical 1.6mm PCB slots in neatly.

The Dreamcast serial appears to be a different sort of connector, the terminals are on the outside of a central bar. What makes you think a PCB would plug in there? There are not many connectors that can use a PCB like that, USB A is about the only one I can think of.

Anyway, there isn’t a set of “general purpose edge connectors”, they just aren’t commonly used like 2.54" pin headers. They are easy enough to create from scratch, provided you can find dimensions.

It’s quite possible you are leading the field, I don’t recall any similar discussion.


#8

Hah! Glad I could help? Thank you so much, once again. I genuinely appreciate it.


#9

Indeed! This is exactly what I was trying to explain, except that I’m apparently not words-ing today, lol.

I was thinking with the DC Serial that I could 3D print a connector that would hold the PCB in the correct orientation to neatly sit atop the pins, provided there’s just enough solder on the pads to elevate them to a thickness of maybe 0.2mm or thereabouts. I dunno, I’m rolling the dice here, but I’d like to make modifications of this ilk as painless as possible for the lay person to implement.


#10

I think that definitely has potential, worth a try anyway.