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low_budget

"NES Super 8" project

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The NES Super 8 does have stereo sound and an improved pre-amp. There is no microphone support. I didn't see much point in adding it since only a handful of Japanese games use it.

 

Just tested Super Mario Brothers 3 today and found it didn't work. :(

It plays fine on the Powerpak, but the original game won't boot.

The NES Super 8 needs 100% compatibility, dammit!

 

I'm assuming the extra work RAM on the cartridge is the issue. I know the cart is good because it works on my original NES. I'll be working on this issue this weekend and I have some more parts coming in so I can work on the composite video.

 

The ram I used is 10x faster than the original NES memory and that on the SMB3 cart, could that be a problem?

I'm wondering if I could configure the Super 8's onboard memory to 4k (for CPU and PPU) and disable any extra cart memory, but I'm not sure if that would make some games incompatible that are currently working.

 

I have 2 extra v1.0 NES Super 8 PCBs on hand, if anyone is interested in helping me troubleshoot this issue, I would offer a reward of some kind. I could sell a v1.0 PCB with parts to an electrically inclined individual for $80, and if they are able to help me correct the problem I would refund that cost and offer an extra $30 (negotiable.)

 

I wanted to get as much done on the project as I could on my own, but I'm not afraid to ask for help.

 

I have also started work on v1.1 of the Super 8, but I want everything working correctly on v1.0 before I have v1.1 manufactured.

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I am really interested in your project and would really like to help out but I am in no finacial postion to buy anything at the moment. I really think this pcb would be great for portables and the like. Was wondering tho, if it were possible to get one to test some things on? I have 2 NES boards one has the older ram on it and the other has slimmer ram on it. So maybe I could test to see if that ram actually works with your issue with the actual game cart not working.

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Tested the RGB Super 8 with the Jrok video converter board today and used a LM1881N sync separator. The s-video looked excellent, but the component video out didn't display properly. Only the top half of the screen had an image, the bottom half was garbage. It seems to be an issue with the video converter.

 

I made a slightly less crappy Youtube video showing the RGB video converted to s-video.

 

Super Mario Brothers 3 DOES work with the Super 8. My cart had a dirty connector, and that was the only problem. If only I checked that earlier...

 

I'm going to try to get one game that uses each major mapper for testing. I've tested games using UNROM, MMC1, MMC3, MMC6, and AOROM and found no issues.

 

I'm still having some issues with the composite video output version. One of the CRT TVs I tried it on was in black and white. The LCD TVs work well, just not CRT. Since a CRT TV is the only way to use the Zapper or ROB I want to get this working.

 

I tried a shorter PPU clock line and it had no effect.

I used a 2N3906 transistor for the video amp and 2N3904 transistors in the clock circuit.

I think component TC1 variable capacitor may be an issue causing the black and white picture on some CRT TVs using composite. Adjusting it seems to have no effect.

 

I have an assembled v1.0 Super 8 and one in kit form if anybody is interested. $60 for the kit or $80 assembled. Anybody want to be a beta tester? Version 1.1 will have the issues I mentioned corrected but will cost more.

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If you made this kind of thing just like a Super 8/Tristar that plugged into a SNES with RGB output, that would be the ultimate! I love the feel of Snes controllers, and the fact that the Super 8/Tristan has a famicom cart slot.

 

I am interested in one of these for testing, as I have a Real RGB monitor.

Edited by RGB_Gamer

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Would your project be compatible with the NES Ethernet project? Mixing the two could have really interesting results. :-)

 

There is no room on the PCB for the entire NES expansion connector, but I will try to add tap points on the PCB for possible wiring of one. IF I am able to do this, it will not be a simple mod. The NES and Famicom have very different wiring of the 74HC368 chips, so I'm not sure how I will label these or if I can make the Super 8 compatible with the Famicom accessories that use its 15 pin expansion connector. Either way these connections will have to be manually wired to the correct port.

 

In the coming weeks I will have a better idea of the improvements I can make with the v1.1 Super 8 board. I am running out of room and don't want to make the PCB bigger.

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Still working on making all games display correctly with the composite PPU.

I ordered an oscilloscope, it should be here next week. I think that would help a lot and decided it would be worth it.

 

I made progress on the case while I'm waiting for that.

I cut the cartridge slot and holes for the controller ports. The cart slot has the chamfered edges so the game can only be inserted the right way.

The controller ports are quite long, so the only place I could mount them is near the cartridge slot on the top.

 

The RGB PPU with heatsink in a socket has plenty of clearance.

 

It's looking like this case will work out pretty well.

post-31751-0-96757800-1353567328_thumb.jpg

post-31751-0-50299300-1353567341_thumb.jpg

Edited by low_budget
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Whoa this's the best clone evar! I spy with my big eye a ths7314 rgb amp built right onto the pcb. Personally I prefer using the sony cxa2075 since that chip both amps the rgb and converts it into very nice looking s-video. I built a circuit that divides the system clock circuit down to 1/6 of the system clock speed to drive the colour subcarrier of the cxa2075 producing a very perfect s-video image, I'm sure someone as smart as you can figure out how to make that.

 

By the way getting the heatsink off of the rgb chip is very easy all you need is some vice grips and a strong flat blade screwdriver that fits in that small slit between the ppu and the heatsink.

 

It also looks like you have trimmer resistors on the audio lines I assume for playing with balance levels.

Edited by Drakon

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I have about 3 extra RP2C03B IC chips that I was going to put up on E-Bay. Got them from old boards that were going to the trash when the company I worked for got sold. All have the heat sinks on them and one has "DUCK HUNT" on it with MDS-DH & 2F or 8F, which I believe is the board locations where they would go. Have a 4th one that I was messing with years ago. Got the video out but very dim if I remember correctly. Going to switch it to a top loader someday and play with it some more now that I have more info to do it...

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Thank you for the compliments!

 

That sounds like a good idea to use the Sony cxa2075, but it seems rather hard to locate a supplier. It would also require a rather major PCB redesign and space would be an issue. I've been using the Jrok RGB-component converter with a lm1881 sync separator. I plan to add the voltage regulator and lm1881 on board for v1.1.

Since I just completed a redesign of the video circuit on v1.1, I think I'll leave the video converter external. On assembled units I think I'll use a Genesis 1 pinout RGB video connector.

 

I like leaving heatsinks on ICs when possible. Since the RGB PPU costs around $200 and is nearly 30 years old, I want to get as much life out of it as possible.

 

I have trimmers on the 3 available audio channels for mixing. Audio input to pin 54 of the cart connector (from powerpak or famicom converter) can be mixed with NES audio channels 1 or 2 using a jumper. I used a LM4808 headphone amp and I think it sounds much better than the original NES hex inverter based preamp. The bass effects sound really good.

 

Just tested Castlevania 3 japanese version with the enhanced sound and it sounds great.

 

I tested games using all the major mappers, and they all work.

 

I will probably offer a RGB ready PCB, as well as a cheaper composite PPU only board.

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By the way getting the heatsink off of the rgb chip is very easy all you need is some vice grips and a strong flat blade screwdriver that fits in that small slit between the ppu and the heatsink.

Nonsense, just squeeze the two fins together and it falls off every time...

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I like leaving heatsinks on ICs when possible. Since the RGB PPU costs around $200 and is nearly 30 years old, I want to get as much life out of it as possible.

I suggest removing the sink off the rgb chip before it falls off on its own and shorts out some circuits inside the console!

It's not glued very well.

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Well whatever's easiest I guess

 

I suggest removing the sink off the rgb chip before it falls off on its own and shorts out some circuits inside the console!

It's not glued very well.

 

low budget I got my cxa2075s for cheap from some random ebay seller. When messing around with the rgb ppu in a nes / famicom I noticed that even when amped the further the rgb travels before being converted into s-video the more blurry the image would become. That's why I think building a cxa2075 circuit or something else that amps and gives you component video on the pcb would be good.

Edited by Drakon

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I'm making good progress on version 1.1.

 

The video circuit was redesigned and has provisions for a LM1881 sync separator.

The clock circuit has been improved. The clock lines to CPU and PPU are significantly shorter than on v1.0 and original NES.

Many chips were moved in closer together.

Tap points added to many important data lines for possible expansion port wiring.

Problems present in the version 1.0 PCB like the voltage regulator footprint and need for grounding jumpers fixed.

Diode arrays 1-4 removed from board. I never installed them in v1.0 and controls work fine.

Lots and lots of little fixes.

 

Even though using a CXA2075 is a good idea I will not be using it in version 1.1 because of a lack of room on the PCB in this area.

 

The Super 8 v1.1 circuit board can be assembled to use a composite PPU or a RGB PPU. The RGB PPU requires additional components and a capacitor needs to be swapped to switch from one PPU type to another.

 

I'm also considering ordering pre-cut cases. I'm pretty good at making cutouts in plastic, but it's very time consuming.

 

At the current rate, it will be probably mid-January before I am able to assemble a v1.1 NES Super 8.

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post-31751-0-78610700-1354921481_thumb.jpg

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Looks awesome. I find that case horrendous but hopefully it can be mounted in a more plain box (are there other cases by that company with the same mount points?) Looking forward to 1.1

Edited by Zapf

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Looks awesome would love to see something like a drop in replacement board for a original intellivision case with better video out. :)

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I'm not sure how I've managed t miss this project. This is extremely exciting and I will buy one the moment they go on sale!

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This is superb work low_budget and I would certainly enjoy having one if you begin producing finalized boards.

I personally am not fond of the Polycase at all, but that is a non-issue as I can make my own body for it.

 

I someday hope to see if you create designs for other consoles, even if actually building them is impractical.

Maybe I'm a little crazy, but I personally see an art form in board designs, regardless of any actual units built.

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