Copying something here that I posted over at Lost Levels. I'm curious how this thing works, and what it's looking at in that initial test that fails in emulators. It may very well have a simple explanation, but I'm not exactly technically inclined! I dunno if it's ok to post the rom here, but there's a link in the thread I started at Lost Levels. The original post is below:
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I'm sure some of you have messed around with the Port Test Cart before. It's been dumped for ages, but it doesn't do much of anything in emulators. When you load it up, it just stops with this error message:
On a real system, the cart needs a special peripheral to complete its tests. This peripheral, as far as I know, isn't supported in any emulator, so it's impossible for the test to pass on an emulated system.
I've owned one of these dual controller setups for a while, and using it with a copy of the test cart rom loaded on a Powerpak, I was able to get video of the test cart running to completion. I admit it's not the most thrilling thing to watch, but it's an interesting little bit of NES trivia that was relatively unknown, and completely undocumented.
Here's a closeup of the board inside the controller. This is all that differentiates the peripheral from a pair of regular controllers.
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I'm sure some of you have messed around with the Port Test Cart before. It's been dumped for ages, but it doesn't do much of anything in emulators. When you load it up, it just stops with this error message:
On a real system, the cart needs a special peripheral to complete its tests. This peripheral, as far as I know, isn't supported in any emulator, so it's impossible for the test to pass on an emulated system.
I've owned one of these dual controller setups for a while, and using it with a copy of the test cart rom loaded on a Powerpak, I was able to get video of the test cart running to completion. I admit it's not the most thrilling thing to watch, but it's an interesting little bit of NES trivia that was relatively unknown, and completely undocumented.
Here's a closeup of the board inside the controller. This is all that differentiates the peripheral from a pair of regular controllers.