DIY

Master System 2 Power Led Mod

Posted by admin on January 06, 2022
DIY, General / No Comments

Since we started modding the Master System 2 on the previous post, I thought I should go ahead and fix another omission of the system. A freaking power led! How would you know when the system is on without one? Well, that’s an easy fix but, since I already mentioned in the previous post that I don’t like modifying these old consoles in a irreversible way, I decided to go the extra mile and 3d print a new power button with the necessary space to let a led shine through it, so I could save the original part.
Link here: https://www.thingiverse.com/thing:4915513

So first thing is first. I already had a bunch of color cycling 5mm leds lying around from my NES mod, so I decided to use one of these as my power led for the SMS2. These are quite fun, since they automatically cycle through many different colors when power is applied.

The way you connect the led is by using 2 pins of this little thingy (which is a Voltage Regulator), which is accessible inside the Master System 2 even without removing the metal shield:

I used a red wire for the positive and the black one for the negative pin of the led. I also used a 75Ohm resistor to connect the positive side (you can see it above inside the red heat shrink).

The led fits nicely inside the 3d printed power button that replaced the original one and the pins and wire come out of the side, so it does not affect its usage which is to actually, well, power the system on and on by flipping the switch below it.

And that is all you need to do. Here is a video of the result, in real life it does not shine so brightly and it looks very nice when powered on.

https://www.youtube.com/watch?v=mJxivBAIsXU

Master System 2 video out

Posted by admin on January 06, 2022
DIY / No Comments

The Master System was SEGA’s answer to the Nintendo Entertainment System’s success but in the early 1980s. While it had some success, especially in Europe, the NES prevailed mostly due to more iconic characters and game designs but also due to the fact that it arrived a bit earlier in most markets. The second iteration of the Master System hardware, the Master System 2, was a cheaper version that lacked a couple of things compared to the original, namely the Sega Card and, most importantly, it could only output video using an RF output. Not ideal. Far from it actually. Funnily enough, the hardware inside can produce the signals needed for composite video and even RGB, but the necessary plugs and wiring were removed from this version.

But today we will fix that! I have all of my retro consoles connected using composite video, with a huge composite video-stereo audio switch and I wanted my newly acquired Master System 2 to be the same. Most mods I saw though required drilling holes in the original plastic body, which I did not want to do (I never do irreversible mods to these old systems). Instead, I decided to use an external small plastic hobby box, attach it on the back of the machine and keep my composite and audio outputs there. The SMS does not produce stereo sound, but I installed 2 RCA jacks connected together so I at least have the option of outputting the same audio from both.

The mod itself is pretty easy to pull off. All you need are the aforementioned RCA female plugs, one 220 uF capacitor, one 100 ohm resistor and a few wires. You need to open up the SMS2 and find the chip marked below:

We will be using one of the pins for ground (pin 1), one for the audio signal (pin 9) and one for the composite video signal (pin 20). The numbers start counting from the bottom left (marked 1) and continue counter-clockwise around the chip around the last one (marked 24).

I have used a white cable for ground, a yellow for audio and a red for video. The white cable is connected to all 3 of the RCA plugs inside the little box, the yellow to the two audio inside and the red, through the resistor and the capacitor to the video RCA as shown below:

For the capacitor, make sure that the negative touches the RCA internal while the positive goes to the motherboard (again, you also need the resistor, which I have on the chip leg itself. You can also choose to do the soldering on the back of the motherboard, where the chip sits.

You can get the cables out using the RF hole, it’s big enough. I will most likely never use RF anyway.

This is how the final system looks from the back. Works and plays great (much better than RF of course).

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Modding an NES – PAL-E console controller support hack

Posted by admin on June 05, 2021
DIY, General / No Comments

A little known fact about the NES is that there are versions of the console that do not support all the controllers out there. The PAL version that came with controllers that have the NES-004E engraved on the back ONLY support controllers with this engraving and nothing else. Controllers from the NTSC version will not work and nor will any knock-off controllers from China.

I recently replaced my controller’s insides with the excellent DIY kit from 8BitDo that turns the original controller into a wireless version that works just as well.

I am using this with the also excellent NES retro receiver and works flawlessly. Since I am using the original chassis and buttons, the feeling is almost identical to the original controller sans the cable. The system worked fine on my PAL NES-E console as well.

But all that changed when I bought a couple of (admittedly very nicely built) knock-off controllers from China. I plugged both on either port on my NES and nothing seemed to work. It would be a huge coincidence for both the controllers to be faulty (I knew the console and both ports worked) so I investigated further.

It turns out that my console only supported NES-004E controllers (the 8bitdo receiver obviously is handling the issue fine). By disassembling the console, I noticed that each controller port was connected to some kind of board which in turn was connected to the main board. These boards had several diodes that obviously prevented other versions of the NES controller to work.

The solution turned out to be surprisingly easy. All one needs to do is bridge all the diodes (essentially bypassing them). You could also remove the whole board and connect the cables directly on the port but I felt this solution was easier to do and more elegant.

This modification is only useful if your NES has this board between each controller port and the main board and you have controllers you want to use that are not recognized. It can also be done in the same way on both ports. Doing this mod does not have any drawbacks, the original controller work just fine. But now, your NES is controller-region-free!