# Connector footprint JAMMA

JAMMA connectors are card edge slots that were common in arcade games before cheap SBCs. They are designed for fairly high current (5A) and are robust and cheap in a range of sizes from 8 to 72 pin.

I can't find a KiCAD footprint for any size of JAMMA connector. This doesn't surprise me, but I also can't find a comprehensive physical specification.

I know there is 3.96mm centre to centre for the pins, and 3.96mm between the rows. They use a flat pin with a hole designed for attaching a heavy wire, with an interstitial gap of 1.8mm. This implies a pin width of 2.16mm requiring a 2.2mm hole and a pad at least 2.5mm wide leaving 1.46mm pad edge to pad edge.

However, JAMMA connectors come in two flavours, the other one having wire pins. The diameter of the wire pins I do not know, and Chinese suppliers have not responded with diagrams. Centre to centre they have to be 3.96mm same as the flat pins with the holes. At a guess the pin diameter is about 1mm but it's hard to be certain until I receive them and use calipers.

I've never created a KiCAD component and it looks like a fair bit of work to do a good job of it. Any information, guidance, encouragement or assistance with KicAD would be appreciated, with the outcome being contributed to the KiCAD libraries.

In particular, can board makers do slots? It crossed my mind you could do a series of 13 0.9mm holes at 0.305mm intervals but I don't know how well the drilling machine would cope.

Even can it be done, slots may not be worth the bother. There isn't a lot of room for the heavy tracks associated with these big pins to escape between the pads (gap of 1.4mm) so I'm going to have to make heavy use of vias and layers anyway.

• JAMMA refers to a standards group, so presumably there is a paper spec somewhere may be in Japanese. I see there are plenty of hobby boards for home arcades using this connector so parts should be available . It is possible that the wire terminated mating connectors have MFG specific pin inserts and not standardized. Board makers can do reasonable slots no problem, but it will usually come with an added cost per board. Note the smallest router bits are typically in the 0.5mm range (smallest drill ~0.1mm), below that it is laser drilling and pricey Apr 11 '19 at 0:38
• You've answered the only part of this question that isn't opinion and I'd accept this as an answer if I could. Spehro on the other hand may have set me on a better path. Apr 11 '19 at 0:50
• If you can't find the standards, you could always get a connector and go to town with calipers. Not the best way of doing things, but it gets results! Apr 11 '19 at 1:18

I am going to ignore all parts of the question that center around if you should use this part at all and concentrate on answering how you could do it using kicad.

I've never created a KiCAD component and it looks like a fair bit of work to do a good job of it. Any information, guidance, encouragement or assistance with KicAD would be appreciated, with the outcome being contributed to the KiCAD libraries.

I have written up an extensive guide on how to make a footprint found here (This includes a lot of tips to reduce points of errors and increase efficiency): https://forum.kicad.info/t/tutorial-how-to-make-a-footprint-from-scratch/11092/ This also shows how to arrive at through hole sizes (including for slots) if there is no suggestion in the datasheet.

In particular, can board makers do slots?

Not all manufactures can do it. The ones that can do it might charge extra for it. Additionally not every manufacturer understands the way how kicad defines them. So make sure you talk to them about this before starting your design.

I know that Oshpark had trouble in the past with the kicad definition but i think they said they solved it recently. Their workaround they proposed in the past would no longer be viable in v5 as edge-cut drawings are now respected by DRC.

• I'd like to say I'm very impressed with all the responses I've had, both answers and comments. This is how Stack Overflow was in its first couple of years, with people actually trying to help each other. Apr 13 '19 at 10:38

It sounds like you're trying to mount a 0.156" pitch edge connector designed for wires into a PCB. That's not going to be very pleasant. Yes, most PCB makers can make plated-through slots down to about 0.6mm wide.

I suggest you confirm that these are just ordinary edge connectors, and if so then use ones that are designed for through-hole mounting. For example EDAC 305-036-520-202 which just requires 0.05" holes. The polarizing key is an accessory.

• As for everything the design is cost driven. I want removable daughterboards and I need at least 40 pins. Most of the pins are signal only but some of them are shared power rails that may drive things like servomotors. Your thoughts and suggestions are appreciated. I see your suggested part is good for 5A, that will do nicely if it's cheap. Apr 11 '19 at 0:44
• What should I search for? The only thing I'm finding for EDAC is power bricks. DigiKey has them … for ten dollars each. That's way too expensive. Apr 11 '19 at 0:53
• Go to a distributor such as Digikey. Search for card edge connectors. 0.156" pitch. Through-hole. Number of positions you want. There are other manufacturers. Apr 11 '19 at 0:55
• I agree about finding something suited to through holes but I can't find anything cheap enough with big contacts. I'm going to buy a couple of the wire pin type JAMMA connectors and measure them. I can get those for 2.2AUD instead of ten. Apr 11 '19 at 1:22
• @PeterWone if there is a connector you need but it is just a little too expensive or needs a small tweak or adjustment, you should contact the MFG or their local rep directly to see what they can do on volume or custom parts. If you rig an imperfect solution you may pay through the nose on PCB assembly. Any hand solder step is  and process reliability is key. Soldering a standard TH is maybe 10 minutes billed, hand inserting wires and delicate solder work maybe 1hr and special jig. This kills throughput and yield . A bespoke connector at a slightly higher price point may be worth it. Apr 11 '19 at 19:31