shmups.system11.org

Shmups Forum
 
* FAQ    * Search
 * Register  * Login 
It is currently Thu Jan 17, 2019 1:58 pm View unanswered posts
View active topics



Post new topic Reply to topic  [ 352 posts ]  Go to page Previous  1 ... 8, 9, 10, 11, 12
Author Message
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sun Dec 16, 2018 5:13 pm 



Joined: 02 Sep 2016
Posts: 88
Thanks very much for the information.

If I have any more questions I'll post another reply. I'm going to be using an NESRGB board in the NES (with the dejitter board) and Voultar's SNES RGB amp in my 1CHIP03 (with the CSYNC lines restored on the motherboard).


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Wed Dec 19, 2018 7:26 pm 



Joined: 02 Sep 2016
Posts: 88
Does anybody have any pictures of wiring a shielded coax cable to the MCLK_o and NES PPU?

Even the smaller (RJ59?) coax cable is very thick and it seems very difficult to wire onto the small pads/pins unless I'm not understanding something?

Image

Also, is it recommend to use any coax wires for the SNES dejitter mod?


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Wed Dec 19, 2018 8:49 pm 



Joined: 08 Mar 2017
Posts: 650
"Coax" became a term most often associated with the kind of cable you pictured.
The term just means that you have an inner conductor for the signal, and an outer conductor that shields it.
The cable can be much thinner, and for this task, it should probably be the smallest type you can find.

Make it a small and flexible cable and keep it short :)


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Thu Dec 20, 2018 1:26 am 



Joined: 02 Sep 2016
Posts: 88
Thanks for the information.

Do you see anything on Amazon (or Mouser/Digikey?) that fits the criteria? It seems difficult to find...


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Thu Dec 20, 2018 1:39 am 


User avatar

Joined: 05 Mar 2018
Posts: 387
sofakng wrote:
Thanks for the information.

Do you see anything on Amazon (or Mouser/Digikey?) that fits the criteria? It seems difficult to find...

There are many types of coax smaller than rg-59

Search for "mini coax" :wink:


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Thu Dec 20, 2018 2:26 am 



Joined: 02 Sep 2016
Posts: 88
Great, thanks! I've order this one from Amazon: C2G 27227 Velocity Mini-Coax F-Type. Supposedly it has 26 AWG wires inside.

Should I use a shielded cable (coax) for the SNES MCLK_o line too?


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Fri Dec 21, 2018 6:45 pm 



Joined: 02 Sep 2016
Posts: 88
Sorry, one more question about the NES csync output and termination (ie. resistors).

The Retro Modding Wiki instructions say to connect NESRGB CS# (J8 open; TTL sync output) to the Dejitter CSYNC_i pad.

If my SCART cable doesn't have a 470 ohm resistor, do I need to add one between the dejitter CSYNC_o and the multi-av output connector? The dejitter GitHub page says it outputs 2.5vpp unterminated and ~1.1vpp @ 75 ohm when terminated?

Similar question for my SNES. I'm using Voultar's RGB amp with my 1CHIP-03 (with csync restored on motherboard because 1CHIP-03 was missing parts for csync). If my SCART cables does have the 470 ohm resistor, then I'm guessing I don't need to do anything here?


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Fri Dec 21, 2018 7:04 pm 



Joined: 21 Aug 2016
Posts: 398
sofakng wrote:
Sorry, one more question about the NES csync output and termination (ie. resistors).

The Retro Modding Wiki instructions say to connect NESRGB CS# (J8 open; TTL sync output) to the Dejitter CSYNC_i pad.

If my SCART cable doesn't have a 470 ohm resistor, do I need to add one between the dejitter CSYNC_o and the multi-av output connector? The dejitter GitHub page says it outputs 2.5vpp unterminated and ~1.1vpp @ 75 ohm when terminated?

Similar question for my SNES. I'm using Voultar's RGB amp with my 1CHIP-03 (with csync restored on motherboard because 1CHIP-03 was missing parts for csync). If my SCART cables does have the 470 ohm resistor, then I'm guessing I don't need to do anything here?


So a few things. That coax cable you linked to before is going to be huge. I didn't use any coax cable on my install and I have had no issues. I just used some high-quality wire from a Mogami mic snake because I happened to have it lying around, but that's really the main thing is to make sure you are using quality wire.

Regarding the NES, I am not entirely sure what you want to do there, but it does seem like having the resistor inline is not a bad idea. I used a standard SNES cable in my install as that was kinda the point (for me) of using the multiout, so I can't really speak to that.

With the SNES, I believe you are good to go there but someone can correct me if I am wrong.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Fri Dec 21, 2018 9:44 pm 


User avatar

Joined: 15 Dec 2012
Posts: 598
Location: Finland
A cheap way to obtain a decent coax is to cut a leftover composite or audio cable. The reason why coax was mentioned only with NES is because the required distance is longer, making the clock line more prone to EMI & noise. I haven't either had issues with an unshielded cable but there was a few reports some pages back where certain setups (e.g. specific games using Everdrive) apparently generated noise bad enough to infer glitches on clock line until it was shielded.

As for CSYNC_o, you may add the series resistor but it's not strictly necessary, 1.1Vpp is still a safe level for 75ohm terminated video/sync inputs.


Top
 Offline Profile  
 
 Post subject: NES/SNES 240p dejitter mod
PostPosted: Fri Dec 28, 2018 2:31 pm 


User avatar

Joined: 17 Jan 2016
Posts: 243
Maybe a stupid question but if I have a sync on Luma cable, will this mod work for me as I am not using csync


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sat Dec 29, 2018 1:08 am 


User avatar

Joined: 07 May 2018
Posts: 318
You have to either:

route the dejitter board output to the luma pin. Possibly sever the circuit to that pin, if it's a console with s-video enabled. Of course, that will disable s-video.

Or

Rewire the cable, at the console end. May not be possible.

Maybe some way to inject the sync upstream into the luma circuit. The smarter guys around here will know.

Sent from my SM-G955U using Tapatalk


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sat Dec 29, 2018 9:40 am 


User avatar

Joined: 17 Jan 2016
Posts: 243
Thanks

I have 1chip03 and a nes rgb. I am finding the documentation/instructions for installation to be a little sparse on both sides so I am very wary of starting something until I am ready. I may have to buy a csync cable


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Mon Jan 07, 2019 1:04 am 



Joined: 02 Jan 2016
Posts: 80
How would one go about installing the dejitter board alongside borti's superCIC multi-region board in a SNES Mini/Jr.? Each board has its own circuitry using a 21.47727Mhz crystal which replaces X1. The dejitter board requires the removal of c3 but the superCIC board leaves it alone.

Image


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Tue Jan 08, 2019 5:37 pm 


User avatar

Joined: 15 Dec 2012
Posts: 598
Location: Finland
unmaker wrote:
How would one go about installing the dejitter board alongside borti's superCIC multi-region board in a SNES Mini/Jr.? Each board has its own circuitry using a 21.47727Mhz crystal which replaces X1. The dejitter board requires the removal of c3 but the superCIC board leaves it alone.
You should be able to put snes_dejitter board in between there. First disconnect that green wire from SNES mainboard and connect it to MCLK_EXT_i of snes_dejitter instead. Then hook up Mode pin of superCIC board to snes_dejitter CLK_SEL_i. Rest of the snes_dejitter signals you should wire as usual, and you can probably leave C3 there as is.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Thu Jan 10, 2019 9:46 am 



Joined: 02 Jan 2016
Posts: 80
marqs wrote:
unmaker wrote:
How would one go about installing the dejitter board alongside borti's superCIC multi-region board in a SNES Mini/Jr.? Each board has its own circuitry using a 21.47727Mhz crystal which replaces X1. The dejitter board requires the removal of c3 but the superCIC board leaves it alone.
You should be able to put snes_dejitter board in between there. First disconnect that green wire from SNES mainboard and connect it to MCLK_EXT_i of snes_dejitter instead. Then hook up Mode pin of superCIC board to snes_dejitter CLK_SEL_i. Rest of the snes_dejitter signals you should wire as usual, and you can probably leave C3 there as is.


I appreciate the reply. This is actually not my install. I wanted to know if the two boards were compatible with each other before trying this out.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Fri Jan 11, 2019 8:25 am 



Joined: 05 Jul 2016
Posts: 20
I would appreciate if you can send some detailed pictures in this thread after you have done the modding? Same thing needs to be done for my console.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sat Jan 12, 2019 2:23 am 


User avatar

Joined: 02 Feb 2016
Posts: 29
Anyone here successfully installed a disable switch for the version 1.3 board (for NTSC system)?

According to the GitHub, the last paragraph under FAQ states:

Quote:
Is it possible to disable de-jitter functionality after installation?
When the board is installed so that MCLK_EXT_i and CLK_SEL_i are not used, a simple bypass can be added without firmware modifications. To do that, connect MCLK_EXT_i to CPLD pin 34 (MCLK_XTAL_o) and add a ON-OFF switch that connects MCLK_SEL_i to 5V.


2 questions:
1) CPLD pin 34 is the pin that leads to R7 pads on the version 1.3 PCB. Is that correct?
2) Is CLK_SEL_i same as MCLK_SEL_i? Was the later a typo on the quoted FAQ?


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sat Jan 12, 2019 4:12 pm 


User avatar

Joined: 15 Dec 2012
Posts: 598
Location: Finland
BuffaloWing wrote:
2 questions:
1) CPLD pin 34 is the pin that leads to R7 pads on the version 1.3 PCB. Is that correct?
2) Is CLK_SEL_i same as MCLK_SEL_i? Was the later a typo on the quoted FAQ?
Yes and yes.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Sun Jan 13, 2019 2:03 pm 


User avatar

Joined: 21 May 2013
Posts: 128
Is it possible to use the dejitter board on a SNES 1CHIP and output dejittered Composite/S-Video as well as 75ohm CSYNC? Perhaps by lifting the S-RGB video encoder CSYNC input (pin 7) and connecting the dejitter boards CSYNC input and output to both pad and pin? Or would the dejitter board CSYNC levels not be suitable for this?
(All my SCART cables are wired for sync on luma, and although I could rewire them to use MULTI OUT pin 3 this seems risky as I sometimes switch between PAL/NTSC SNES systems, and stock PAL systems have +9-12V on the same pin as CSYNC on NTSC systems)

Also, is anyone working on a design that combines the dejitter board with the 1CHIP 50/60Hz board?
https://oshpark.com/shared_projects/Brpg2thK
Just thought it would make for an easier installation with less wires.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Mon Jan 14, 2019 12:52 am 


User avatar

Joined: 02 Feb 2016
Posts: 29
Thanks for the confirmations.

marqs wrote:
BuffaloWing wrote:
2 questions:
1) CPLD pin 34 is the pin that leads to R7 pads on the version 1.3 PCB. Is that correct?
2) Is CLK_SEL_i same as MCLK_SEL_i? Was the later a typo on the quoted FAQ?
Yes and yes.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Mon Jan 14, 2019 4:33 am 



Joined: 02 Jan 2016
Posts: 80
Decoryah wrote:
I would appreciate if you can send some detailed pictures in this thread after you have done the modding? Same thing needs to be done for my console.


No problem. I just don't know when that will be as I don't even have the parts yet.


Top
 Offline Profile  
 
 Post subject: Re: NES/SNES 240p dejitter mod
PostPosted: Mon Jan 14, 2019 5:17 pm 


User avatar

Joined: 15 Dec 2012
Posts: 598
Location: Finland
Link83 wrote:
Is it possible to use the dejitter board on a SNES 1CHIP and output dejittered Composite/S-Video as well as 75ohm CSYNC? Perhaps by lifting the S-RGB video encoder CSYNC input (pin 7) and connecting the dejitter boards CSYNC input and output to both pad and pin? Or would the dejitter board CSYNC levels not be suitable for this?
(All my SCART cables are wired for sync on luma, and although I could rewire them to use MULTI OUT pin 3 this seems risky as I sometimes switch between PAL/NTSC SNES systems, and stock PAL systems have +9-12V on the same pin as CSYNC on NTSC systems)

It's possible like you said, but for lifted S-RGB pin 7 you should tap c-sync right from snes_dejitter CPLD (pin 15) instead of CSYNC_o pad which is after a transistor driver and series resistor. If you are planning to use the setup with OSSC, it's also possible to leave S-RGB as is and just increase H-PLL post-coast to ignore the short scanline and the canceling long scanline followed by it (as seen on S-RGB input after the mod).


Top
 Offline Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 352 posts ]  Go to page Previous  1 ... 8, 9, 10, 11, 12

All times are UTC


Who is online

Users browsing this forum: DialKnight, Fudoh, Google [Bot], Ruprit, SuperSpongo, Syntax and 14 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Space Pilot 3K template by Jakob Persson
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group