Installing Mark Spaeth’s Jr. Pac-man Toggle Speed Chip Kit

Took me over a month to finish installing Mark Spaeth’s Jr. Pac-man speed up kit, but I can finally rest easy know that my switch is no longer hanging out of my coin door. There was a couple page thread about the kit on the klov forums, mostly people looking to make their Jr. Pac-man gameplay faster. But, towards the end of the thread, there were some good photos and some advice as people started to get the chip replacements in the mail.

After I read about the different ways that people installed their kits, and how they mounted them in their cabinets, I had a hard time trying to figure out how to mount mine. The one set of photos I saw, was of an individual who has a Jr. Pac-man conversion in a Pac-man cabinet. 2PacMan also had wisely bought a switch from K-Mart that was threaded and this made it fairly simple to mount his switch on a shim right inside the coin door. But, after asking questions about what type of simple switch to buy from Radio Shack, I still managed to buy one that made my life harder.

So, here are the installation and mounting steps I went through to ready my Jr. Pac-man speed up kit for use.

1. The Kit Arrives

As you can see, there is plenty of slack in the wires coming off the speed up chip to run to your switch on the front of the Jr. Pac-man cabinet, wherever you want. And the brilliant part for guys like me and for a better way of explaining it, the wires are double wrapped around the bottom of the chip’s frame to prevent someone from pulling the wires off and breaking the solder connection.

Here’s a photo of the Jr. Pac-man chip with the simple toggle switch soldered and ready to go. For those of you who are really interested, the part number of the toggle switch that I got at Radio Shack is;

Toggle Switch
DPDT Micromini
275-626A
Contacts rated 3A at 125VAC/1A at 250VAC

Now, it’s time to install the switch on the Jr. Pac-man PCB.

2. Pry the old chip off the PCB board.

There is a row of 5 RAM chips marked at “8D” on the PCB including 8E, 8H, 8J etc. etc. You are going to be replacing the 8D chip, if you haven’t found this bank of chips yet, one of these two photos should help you locate them on either the Jr. Pac-man field board or the original PCB.

Take a small screwdriver, or a chip puller, and slowly pry or pull that Jr. Pac-man 8D chip out of there. I won’t cover the details in this tutorial on how to careful extract a chip without bending the pins. There are many sites out there that talk about this, and all you really need are a pair and some practice.

Now, take the new Jr. Pac-man Speed Up chip, and press it firmly into the socket. Always remember to match the orientation and don’t insert it backwards. A couple of ways to check chip orientation, make sure that the half circle insert on the chip matches the insert on the socket. Or, you can look at the orientation (usually) of the other chips.

This is what your kit should look like once it is installed;

This is where I got hung up. I put the board back in the game, powered it up, and the game played fine, but the toggle switch wasn’t working the way I had it soldered. I soldered the wires to the first two connections, there were three pairs, six connections in all on this toggle switch. I had read somewhere that maybe the connection had to be open, so I unsoldered one of the wires to test that theory. Nothing.

Here is the blurry photo that 2PacMan took of his nice, two connection, threaded slide switch he got from K-Mart.

This doesn’t help me choose which leads to solder to on my toggle switch, and taking an accurate ohm reading on the connections is also giving me fits. It wasn’t until I posted again on the groups just before I left for Michigan that DogP was able to help me out. He said I needed to solder one wire to the first connection, and then one wire to one of the middle connections, which are a little bit taller.

Made the solder changes, fired up the game, and my switch was working! Now, onto mounting it in the Jr. Pac-man cabinet.

Mark Spaeth had suggested making a shin, (a small rectangular piece of wood) drilling a hole, mounting the switch and then mounting the shim on the inside of the coinbox. But, I wasn’t crazy about this idea for a couple of reasons;

1. I could get a thicker piece of wood, but this idea didn’t seem too sturdy to me since it was really only fastened on one end.
2. I wasn’t sure how to mount my unthreaded toggle switch in the shim

I had this idea for a different wooden structure, with a hole in the middle for the switch with no idea how to mount the switch.I had a friend down after Christmas who is much better with tools, fabrication and working with her hands. She suggested getting some sort of rubber O-ring or grommet from the hardware or auto parts store. Good idea, let’s build the housing and then I find something to work for the toggle switch.

3. Build the toggle switch housing

I had one of those thin separator boards that you found in Midway cabs, like the Pac-man’s, between the coin box and the PCB and Power Supply. As you can see, I had used it when I stripped the paint from my old Pac-man cab earlier this year. Since I didn’t have a saw that I could get a nice cut, I decided to use an exacto knife and cut the board into thin pieces.

I measured in 3/4″ for the thickness of the strips. The wood isn’t that strong, and I have to put screws through it, so I didn’t want it too thin and then splitting under pressure. I cut three of those strips. I figured I would be cutting a 5 x 4″ face piece where the toggle switch would actually mount. That meant that each of my little strips would be five inches, and I planned on stacking them four tall.

Each thin cut strip was 16″, so I got (3) 5″ pieces out of each, a total of 9 with one left over.

Here’s what I had after everything was cut, my 5″ strips, and my face plate to mount the toggle switch;

And here is what I am envisioning the housing to look like once it is glued. It gives me a little lift for the back side connections of the toggle switch.

Time to glue the pieces. I didn’t score them, the one side of the wood had a smooth finish, but I figured I would be letting the glue sit for a couple of days, so I should be fine. Titebond II Premium Wood Glue is strong and hasn’t failed me yet.

The final elevated strips glued together. I would have liked to have everything look nice, even though it is going inside the machine. But I was limited on my tools, and didn’t want to draw things out by borrowing some to do the job “perfect” Besides, these are on the underside of the faceplate, so if their edges are uneven and rough with glue and pencil markings on them, it’s no big deal.

I don’t plan on gluing these with the Titebond to the faceplate, I think the screws will be good enough to hold everything in place and it gives me more options for starting over if I did something wrong, even on this simple project.

I looked at Lowe’s, they didn’t have anything but metal grommets. I needed an opening of 3/8″ for the base of the toggle switch to slide through, give or take. So, I asked a buddy who does auto repair to see what he had, and after looking through a plastic box of different parts and pieces, I found just what I needed.

Here is the rubber grommet / gasket I found that perfectly fit the toggle switch, 3/8″, and the hole I drilled in the faceplate to fit it. My buddy told me later, that he thinks this is a rubber gasket grommet for a Volvo or BMW. If I find a part number or some other identifier, I will post it here

And the rubber grommet hot glued to the board. This didn’t end up holding after I tried to push in the toggle switch. I had to reglue it with super glue.

I bought 1″ sheet metal screws from Lowe’s to hold everything together.

The final photos of the switch mounted on the inside of the Jr. Pac-man. Originally, I thought I was going to mount the toggle switch and housing the the exact board I made the mount out of, the separator board between the coin door and power supply. But after I started to screw everything together, I realized that this wasn’t going to hold, and I had a much thicker board to work with right below behind the coin box.

Granted, the switch is a little low for how I was originally picturing it. I don’t think anyone else would know when they open the coin door that this was anything but my intention, but everything worked out ok. I would have probably used 1 1/4″ screws if I had to do it again since that bottom composite board is thicker and that size would hold everything together better. I just liked out it turned out, almost looks like it is factory, if it wasn’t so rough, but it blends right in minus the loose wire.

The whole process for a lot of people is probably overkill for mounting the Speed Up Kit in the Jr. Pac-man. Overkill in the way I mounted it, and that I wrote this long tutorial on it. But, if this is at all helpful to one other person, someone else like me, then it was all worth it.

Here are some similar arcade posts

• Sanding Pac-man cabinet, wiring Mr. Do!
• Putting WG4700 Series monitor in R-Type
• How do I get the Pengo Sound Control Panel Out?
• Pengo board arriving today.
• Re-attached harness connector to Dig Dug

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