ATX to Midway 90411 Power Supply Adapter


This adapter allows you to use a standard ATX computer power supply in your Midway cabinet (including Galaga, Bosconian, Gorf, Wizard of Wor, Robby Roto, and others) to replace the stock 90411 power supply. The board includes a power-on reset circuit, as required by some games.

Many games that use this power supply require -5V so newer ATX supplies that lack -5V may not work with this adapter in your specific game.

Price: $20.00

Nintendo Switchers?

So, a long time ago, I made some prototypes for an expandable Nintendo game switcher system where you could daisy-chain multiple switch boards and then use P1+P2 start together to toggle through the installed PCBs. Due to glitches on the power rails when the relays turned games on and off, the switch boards would sometimes lose state and end up with more than one board powered at a time (or none at all), which the power supply didn't particularly like. While these problems are fixable I never felt motivated enough to spend the fat cash needed to do another run of prototype boards, since sales of JAMMA adapters crashed and there were no longer any sure-sale products to subsidize the cost of prototyping boards in large panels.

Since then, however, there seems to have been a decent proliferation of Chinese-made JAMMA PCB switchers at prices too low for me to compete with, but nobody's really used them for Nintendo since they'd need a Nintendo to JAMMA Adapter for each board plugging into the stack and a JAMMA to Nintendo Cabinet Adapter to plug the whole setup into their game, which leads to a rather expensive solution. If all you're doing is playing Nintendo games in a Nintendo cabinet, all of the video inverters and audio amps are really just going to waste, so there's really no reason to pay for putting them on the adapters.

Thus, I'm proposing the following solution: specialized adapters built without these addition circuits expressly for use with switchers. In quantity, I should be able to have these made at a ~$30/adapter price point, so for a 4-game switcher setup, you'd be looking at the cost of the switcher itself, plus $150 in adapters (4 Nintendo to JAMMA + 1 JAMMA to Nintendo).

Comments? Email me at

With a few pre-orders, I could have these shipping within a couple weeks. -- Note that the JAMMA switcher would need to support -5V as most Nintendo boards require it. If the switcher power cycles all the boards, it'd need to support switching the -5V as well. If the switcher leaves all the boards powered, you'll need to upgrade your power supply to one that provides enough juice to run all of the boards you plan to install.

Well the adapter PCB layouts came together nicely, but it looks like the existing switchers on the market may be insufficient for Nintendo -- MultiJAMMA doesn't switch power, and the Y-Plus 6-1 Switcher doesn't even supply -5, let along have relays to switch it (nor does their 2-1). I'm not sure about the Mike's Arcade 2-1, but I'll look into it.

MB12421 Replacement


This plug-in board uses a Xilinx CPLD to replace the functionality of the MB12421 (data shifter) custom ASIC used on many Taito and Midway B&W 8080 PCBs. This plug-in will also replace the stock daughterboard used on some Midway PCBs to replace the MB12421

Price: $20.00


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