MAME Project: extending the harness


As I mentioned, the wires on the provided harness are no where near long enough to reach the interface board when mounted in any spot other than just behind the keyboard (and that’s where the monitor needs to live).  So, I had to extend them.  This involved 22 gage wire, shrink-wrap tubing, and 22 gage female spade-lug connectors (red plastic sleeves, blue are 14 gage).

This was very tedious, but worthwhile, as now I can mount the board in a more convenient location.  Also, I can now wire up both of the pinball “flipper” buttons which are on the front of the control panel.

I extended the harness by cutting off the molex connectors on the PCB end with small pigtails of wire left on them, then spliced in longer wire.  If I could have found a convenient source for those particular molex connectors, it would have been quicker to just make all new harnesses.

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To make these splices, strip the wires, and don’t forget to slip a piece of shrink-wrap tubing over the longer wire.  Slide this down away from where you are soldering as it’s easy to accidentally heat it and have it shrink where you don’t want it shrunk!  Twist the wires together and solder them, then fold the joint flush against the wire.  Slide the shrink wrap tube up the wire and over the splice then heat the tube to shrink it:

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Here’s a close-up of the panel.  You can see in this shot what I was talking about with separating the common wire for a group of switches for ease of routing:

 

 

 

With the panel mounted back in place with a couple of screws to temporarily hold it, I was able to neaten up the cable harness (cable ties are your friend, remember!)  To the right you can see the Player 1 / Player 2 start buttons.

When rewiring this whole mess to extend the harness, I decided to put Player 1 on the left and Player 2 on the right, rather than my swapped setup.  It really wasn’t much different for single player use, and for games like Robotron, the controls are backwards which is really a mind-trip.  So, enough of my cleverness, we’ll go back to a conventional layout.

Here is a close-up of the interface board with the spliced wiring:

I popped the monitor in place to test, and everything worked fine.  I did have to take the panel off one more time to tweak one of the micro switches on the left (Player 1) joystick as it would not switch off with the stick centered.

Next up: Mounting the monitor

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By Tim Posted in MAME Tagged

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