Making JAMMA edge connectors easier to use with SCSI cables

[mojo]

I'm working on a new Supergun and always find Jamma edge connectors quite hard to use. They are often very stiff, and are not designed for frequency connection and disconnection. I want to replace them with something easier to use, like a Centronics connector:



50 pin types are used for SCSI and the cables are cheap. I have some nice short ribbon ones (10cm). My plan is to make a JAMMA to Centronics adapter PCB. I would fit one to every game and then I only need to plug in the Centronics cable, which is fairly easy.

Obviously the JAMMA connectors has 56 pins and SCSI has only 50, plus single wires won't carry enough current for the power supply, so I have a few options:

1. Use a separate power cable with +5V, -5V, +12V and GND
2. Remove some signals like the coin counters, mount the service/tilt/test switches on the adapter PCB
3. Use a 68 pin SCSI cable instead, with multiple wires for power

In addition to the JAMMA signals I would like to include a small EEPROM memory on the adapter board, so that when plugged in the Supergun could recognize the game and load the right settings automatically. I want to support Sega Saturn controllers and maybe Playstation.

Has anyone tried anything like this? What do you guys think? Signal integrity should be okay I think, I don't expect any video problems or stuff like that.

[mojo]

I am really the first person to have this idea? Or is it just that I'm the only one who struggles with edge connectors?

[emphatic]

This doesn't sound like a very good solution to me, sorry. The only time I change a game out in my cabinets more than twice a month is if I have a shmup meet, so I don't see how the "problem" with a tight JAMMA connectors in any way that would warrant such a contraption. If anything, you'd want the connector to sit snug on the PCB connector? Also, using a connector where you can't run the power through them sounds awkward as hell.

I think you'd be better off getting a JAMMA switcher to keep a few games in circulation, or just concentrate on one game a month. Or are you using your cabinet to test PCBs mainly?

[cools]

Get one of those protection covers fitted to the harness, it'll make it far easier to remove the connector

[mojo]

Fair points guys. I did look at the edge connector covers, but I have a couple mounted on PCBs that I use with my current home-made supergun and still find it a bugger with some games. Perhaps I just need better edge connectors, because I don't recall having this much trouble with old computer cards or games consoles. I suppose they are designed to go in once and stay in, hence the high retention force.

I only play games for fun, so won't be changing too often I think. It would just be nice for it to be easy.

[kowal]

some problems exist only on Hirose and Suzo connector
both have very strong pins (suzo more stronger)
Hirose looks amazing but housing is very fragile

but all other card connectors hold card easy
especially all molex type and chinna black connector solder type
molex is very smooth to remove from card

I am really the first person to have this idea?

no
cenctronics use Wolf
http://www.wolfsoft.de/shop/product_inf ... sole).html

realy? is very stupid solution JAMMA have good design and pinout
do not be smarter than the Japanese
is well
you should not change this
I use only one modification 6 button on 27 and e on one side- for MAK or cabient

Get one of those protection covers fitted to the harness, it'll make it far easier to remove the connector

exactly

[Ed Oscuro]

JAMMA appears to have a good electrical design and layout, but the mechanical design (coming secondary) is not so great, as the very long connectors can easily warp or require a lot of force on the pins (leading to wear). It is pretty amazing how much wear some old JAMMA connectors have despite likely not having been swapped out as much as a home game cartridge.

Does SCSI handle the same voltages safely?

[mojo]

some problems exist only on Hirose and Suzo connector
both have very strong pins (suzo more stronger)
Hirose looks amazing but housing is very fragile

but all other card connectors hold card easy
especially all molex type and chinna black connector solder type
molex is very smooth to remove from card

That explains a lot as I only have Hirose and Suzo connectors. Do you have a part number for Molex card edge connectors? I can't find them available anywhere.

[mojo]

Does SCSI handle the same voltages safely?

It's more the current you need to worry about. Lines would need to be paralleled up to carry enough.

[kowal]

original Molex is hard to find
molex type 4-5y ago sell Suzo with full harnnes

chinna solder type
http://www.ebay.com/itm/Arcade-JAMMA-Ca ... 3cc9254faf

crimp type
https://www.mikesarcade.com/cgi-bin/store.pl?sku=CECM56

[mojo]

Thanks, I'll order a few and see what they are like.