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Messages - GadgetUK

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EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 24, 2016, 11:09 AM »
I would start with the Copper tape - it's much less destructive to the board, easier to do and will very likely fix the problem without needing that resistor.

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 24, 2016, 12:18 AM »
Yes, you've described the issues I had with SMB2!   That's good news!!  I did another fix last week that I finally posted today:-

It's a long shot - I am just going off the symptoms described, they seem too similar to the issues I had getting a 72pin N8 working with my Famicom and an adaptor.  I've done an update in the last week which completely solved the remaining issues I had with SMB2 - I added some copper tape and grounded it - the tape covers the traces and vias on the adapter, and it does appear to have completely solved any remaining issues I had previously.  If there are instances where some games and everdrives work with some NT's and not others, I would suspect a similar problem.   Therefore, maybe the resistor might help on the M2 line, but I suspect adding a ground plane with copper tape like I did might help also.  I guess it just needs someone who has an NT whos willing to experiment.   If it wasn't something like this I suspect it would have been fixed already by a firmware update.  Since that seems to have died out as a possibility (from what I've read), my guess is ringing or noise on one or more of the buses.

EDIT: Sorry I didn't answer your question there!  You could add the resistor in series in either place, ie. either at the everdrive end (but that would require a mod to the PCB) or at the NT end.  I would perhaps try the copper tape ground plane mod first, as that's pretty none destructive.  Just stick the tape over the traces, and solder a wire to the nearest ground.   It's just a suggestion, I have no idea whether it will make any difference to the NT.  Wish I had one now to tinker with lol.

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 22, 2016, 01:17 AM »
Test SMB2 & 3 as well - those were glitching as well, resets and lockups.

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 21, 2016, 09:00 PM »
Original Famicom!  I will check Metroid later!

EverDrive N8 / Re: Individual N8 Mapper Updates (unofficial)...
« on: August 17, 2016, 08:56 PM »
Thanks for the info - that's great!!!

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 17, 2016, 03:46 PM »
That's really strange!  I have read about people having the same issue I had when using a 72 pin N8 with one of these adapters!  Very odd, but it is working now.  If I remove my M2 wire with the 100 ohm resistor the glitches come back.  Could be a problem related to my Famicom revisions or something - or maybe a glichy CPU or PPU perhaps.  This system has been re-capped as well.  In any case, your mods work fine =D

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 17, 2016, 01:23 PM »
I did two things - Firstly I lifted the M2 line on the 72 pin connector - so the pin from the 72 pin socket is not connected to the PCB, but I also made a very small cut in the trace (right next to the via on the 60 pin side), then used a wire from the M2 pin on the 72 pin connector, through a 100 ohm resistor and the other end goes to the M2 pin on the 60 pin side.   If you don't cut the trace leading to the 60 pin M2, then the trace runs in parallel with the wire and its the trace that's part of the problem.   So in summary you end up with a wire for the M2 line, running through a 100ohm resistor, and the original PCB trace should not be connected at all.  I've not been able to create any glitches or crashes / lockups since doing this.  Only time will tell whether its a perfect fix but it does seem to be working for me with my 72 pin N8 on the Famicom here.   There are so many variables and really it needs someone more experienced to take a look I think, but it does seem to have solved my problems with my Famicom.

Could someone try adding a 100ohm resistor in series with the M2 pin, and perhaps the system clock pin if you are using a 72 pin socket.  Here's the pinout for reference:-

I've been experimenting and adding a 100ohm resistor on the M2 line brings 100% stability for me when using the N8 NES cart with a Famicom adapter on a Famicom.   I do believe in the case of the adapter its the length of the M2 line and where its routed.  I think there's an impedance problem in some scenarios - in my case the Famicom adapter, but I cannot help but wonder if the same problems with ringing might exist when trying to use one of these carts with the NT.

Worth noting that I removed that cap from the M2 line as it was causing IRQ timing problems, and instead I've been testing with a pull down resistor on the M2 line instead, and it would appear to be working better than the cap did - ie. no IRQ timing issues.  But this doesn't relate to the NT - just me trying to get the N8 to play happy with the Famicom.

EverDrive N8 / Re: Japanese games on everdrive N8
« on: August 14, 2016, 12:06 PM »
I just bought the original Famicom, but that does only output NSTC-J RF as default.  I've modded it to output composite and its pretty good.  I think the easier option is to get the newer Famicom (the one with the rounded grey shell).  The reason you get the graphical glitches or some games just not working is that Nintendo in their infinite wisdom made the PPU and CPU region specific, so the NTSC CPU and PPU run at a different clock speed than the PAL CPU and PPU, and internally they have different timings related to the number of scanlines drawn etc.   So games from one reason can run on another but timing differences mean that code could be running before or after the time when it 'should' run, meaning possible glitches or crashes etc.  For example if you play PAL games on the Famicom the music is much faster, because the CPU is running faster on the NTSC machine, vs code that was designed to run at the slower PAL clock speed.

I am not sure what mappers the multicarts provide tbh - but I believe they work well (minus the fact that some of them don't have save support).

EverDrive N8 / Re: Individual N8 Mapper Updates (unofficial)...
« on: August 14, 2016, 01:00 AM »
I wondered if someone could clarify the process on installing these new mappers.  I understand that just replacing the mapper files is all that's required, or is there another file that needs updating to?  I noticed that some of them have a different name - ie. the mapper name number, rather than just a number plus extension.  Is some renaming required?  Ideally I would like to add all of the new mappers in the earlier part of this thread, but I don't want to lose any other mappers.

EverDrive N8 / Re: Japanese games on everdrive N8
« on: August 14, 2016, 12:58 AM »
Yes - as others have said, you need an NTSC system to play many Japanese and US games properly.  That's why I recently picked up a Famicom - that will run US and JPN games perfectly!

Today I ran into the problems some others have had using the N8 with one of those 72 pin to 60 pin adapters and a Famicom (games hanging, reseting, crashing etc).  I found that adding a 68pF cap to the M2 line brought stability back.  I've yet to test many more games but all the games I tested with worked.   I wonder if a similar mod might help with the N8 on the Analogue NT.  You could try adding the cap to your Everdrive - but obviously will void warranty.  Worth a try as a last ditched attempt.

EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 14, 2016, 12:37 AM »
Just wanted to say thanks for posting this guide!  I did this today, but also added a 68pF cap to the M2 pin, which solved instabilities with my Famicom.  I was having hanging / lockups with games, and resets etc when using an N8.

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