Title: Nintendo64 RGB DAC
Post by: viletim on January 15, 2007, 10:28:52 PM
Post by: viletim on January 15, 2007, 10:28:52 PM
I've been playing around with CPLDs (programmable logic ICs) recently and though I'd have a go at making an RGB DAC for the N64 out of one... Continuing on from the work of Aidan in this thread (http://nfggames.com/forum/index.php?showtopic=1722).
Aidan had it pretty much spot on - there are four 7-bit bytes of data sent from the RCP to the DAC. The first byte contains timing signals, second byte - red video, third - green video, and fourth - blue video. 7 bits * 3 colours = 21 bit RGB.
My CPLD counts the clock pulses from the RCP and stores the the RGB data in some flipflops. The timing signals (csync, hsync, clamp and vsync) are also available. The digital data is converted to an analogue video signal with binary weighted resistor DAC. I just used the closest values I had so it's not really optimal. I'll draw up a 74 logic equivalent of what's inside the CPLD in a little while...
Here's a screenshot screen shot (http://members.optusnet.com.au/eviltim/temp/n64rgb_ss.jpg) from my RGB monitor.
Aidan had it pretty much spot on - there are four 7-bit bytes of data sent from the RCP to the DAC. The first byte contains timing signals, second byte - red video, third - green video, and fourth - blue video. 7 bits * 3 colours = 21 bit RGB.
My CPLD counts the clock pulses from the RCP and stores the the RGB data in some flipflops. The timing signals (csync, hsync, clamp and vsync) are also available. The digital data is converted to an analogue video signal with binary weighted resistor DAC. I just used the closest values I had so it's not really optimal. I'll draw up a 74 logic equivalent of what's inside the CPLD in a little while...
Here's a screenshot screen shot (http://members.optusnet.com.au/eviltim/temp/n64rgb_ss.jpg) from my RGB monitor.
Title: Nintendo64 RGB DAC
Post by: NFG on January 15, 2007, 10:53:42 PM
Post by: NFG on January 15, 2007, 10:53:42 PM
That's bloody awesome, good work.
Title: Nintendo64 RGB DAC
Post by: blackevilweredragon on January 16, 2007, 01:50:10 AM
Post by: blackevilweredragon on January 16, 2007, 01:50:10 AM
21-bit color? I thought nintendo said the console could do 24-bit color..
(confused)
(confused)
Title: Nintendo64 RGB DAC
Post by: kendrick on January 16, 2007, 02:27:54 AM
Post by: kendrick on January 16, 2007, 02:27:54 AM
Tim, that is excellent work. I imagine this brings us one step closer to a homebrew Component and/or VGA cable for the Gamecube, given the theoretical similarities.
Dragon, as I understand it, commonly the bit-depth of data is often overstated by one digit in order to get a nice round number divisible by eight. The argument is, that extra bit is there but it's always zero. One more reason to completely distrust any kind of media hype or technical specs.
-KKC, being paid for making up numbers.
Dragon, as I understand it, commonly the bit-depth of data is often overstated by one digit in order to get a nice round number divisible by eight. The argument is, that extra bit is there but it's always zero. One more reason to completely distrust any kind of media hype or technical specs.
-KKC, being paid for making up numbers.
Title: Nintendo64 RGB DAC
Post by: blackevilweredragon on January 16, 2007, 02:36:24 AM
Post by: blackevilweredragon on January 16, 2007, 02:36:24 AM
oh, ok, so it's like how my LCD is supposed to be 24-bit color, but tech tests show it was only 20-bit, with massive "dot interlacing" to simulate the higher color...
Title: Nintendo64 RGB DAC
Post by: Endymion on January 16, 2007, 05:48:51 AM
Post by: Endymion on January 16, 2007, 05:48:51 AM
I want to be viletim when I grow up.
Title: Nintendo64 RGB DAC
Post by: radorn on January 16, 2007, 08:05:15 AM
Post by: radorn on January 16, 2007, 08:05:15 AM
whoa.
I didn't visit here in months, then I remembered that new rgb mod from Aidan that seemed to be dead from inactivity and thought to myself "Why don't go see if someone said anything new about this in all this time??"
I have to say this is my lucky day HAHA... maybe if I had come earlier...
Thanks, viletim!
Sorry if this is considered littering as I'm not adding anything useful to the thread, but I just had to say it.
I didn't visit here in months, then I remembered that new rgb mod from Aidan that seemed to be dead from inactivity and thought to myself "Why don't go see if someone said anything new about this in all this time??"
I have to say this is my lucky day HAHA... maybe if I had come earlier...
Thanks, viletim!
Sorry if this is considered littering as I'm not adding anything useful to the thread, but I just had to say it.
Title: Nintendo64 RGB DAC
Post by: viletim! on January 16, 2007, 10:39:27 PM
Post by: viletim! on January 16, 2007, 10:39:27 PM
Well...there are definately only 21 bits there. However there is some kind of hardware dithering going on. If you connect a single bit up to a monitor you'll notice that some of pixels that are on the edges of some picture flicker a lot. I'll admit it confused me for a while...I thought there was something wrong with my flip-flop latches. Once all the bits of a colour are connected through the DAC flickering edges dissapear.
If anyone's interested you can do a simple test to see what I mean: Connect a 1k resistor to one of the data bits (the high order bits show it more clearly...the low order bits are a total pixel flickerfest) and another 1k resistor to the compostite sync output on the DAC. Connect other ends of the resistors together and connect that signal to the composite video of a TV.
Maybe Nintendo thought this kind of dithering effect was so shit hot that the upgraded their specs. :)
If anyone's interested you can do a simple test to see what I mean: Connect a 1k resistor to one of the data bits (the high order bits show it more clearly...the low order bits are a total pixel flickerfest) and another 1k resistor to the compostite sync output on the DAC. Connect other ends of the resistors together and connect that signal to the composite video of a TV.
Maybe Nintendo thought this kind of dithering effect was so shit hot that the upgraded their specs. :)
Title: Nintendo64 RGB DAC
Post by: RARusk on January 17, 2007, 12:47:35 PM
Post by: RARusk on January 17, 2007, 12:47:35 PM
"I want to be viletim when I grow up."
Doesn't everyone?
Anyway it appears that you have a nice bright picture coming out of the N64. Does this thing work on all N64s or just the more recent ones? And do you have to program that chip first before using it?
Doesn't everyone?
Anyway it appears that you have a nice bright picture coming out of the N64. Does this thing work on all N64s or just the more recent ones? And do you have to program that chip first before using it?
Title: Nintendo64 RGB DAC
Post by: blackevilweredragon on January 17, 2007, 12:59:48 PM
Post by: blackevilweredragon on January 17, 2007, 12:59:48 PM
QuoteWell...there are definately only 21 bits there. However there is some kind of hardware dithering going on. If you connect a single bit up to a monitor you'll notice that some of pixels that are on the edges of some picture flicker a lot. I'll admit it confused me for a while...I thought there was something wrong with my flip-flop latches. Once all the bits of a colour are connected through the DAC flickering edges dissapear.just tried..
If anyone's interested you can do a simple test to see what I mean: Connect a 1k resistor to one of the data bits (the high order bits show it more clearly...the low order bits are a total pixel flickerfest) and another 1k resistor to the compostite sync output on the DAC. Connect other ends of the resistors together and connect that signal to the composite video of a TV.
Maybe Nintendo thought this kind of dithering effect was so shit hot that the upgraded their specs. :)
that's EXACTLY what my LCD monitor does!
Title: Nintendo64 RGB DAC
Post by: Dr.Wily on January 18, 2007, 04:00:21 AM
Post by: Dr.Wily on January 18, 2007, 04:00:21 AM
Good work guy !
Title: Nintendo64 RGB DAC
Post by: viletim! on January 19, 2007, 01:09:26 AM
Post by: viletim! on January 19, 2007, 01:09:26 AM
I've been playing around with some different designs for the resistor ladder... I think i'll just go with a more accurate binary weighted design - two resistors for most bits.
RARusk,
So far I can only guarentee that it works on my N64 but I beleive that it will work on any model/region N64. The CPLD does need to be programmed.
If all goes well then I'll make up some small PCBs and sell the programmed CPLD, resistors and board as a kit or something. Unfortunately it seems Futurlec (the only (semi)local supplier of CPLDs) may have recently stopped stocking the part I'm using (XC5936XL) - it's no longer listed on their website.
RARusk,
So far I can only guarentee that it works on my N64 but I beleive that it will work on any model/region N64. The CPLD does need to be programmed.
If all goes well then I'll make up some small PCBs and sell the programmed CPLD, resistors and board as a kit or something. Unfortunately it seems Futurlec (the only (semi)local supplier of CPLDs) may have recently stopped stocking the part I'm using (XC5936XL) - it's no longer listed on their website.
Title: Nintendo64 RGB DAC
Post by: viletim! on January 28, 2007, 02:05:58 PM
Post by: viletim! on January 28, 2007, 02:05:58 PM
I've put up a page with a circuit and programming files HERE (http://members.optusnet.com.au/eviltim/n64rgb/n64rgb.html). The DAC circuit I settled on is an R2R type with no output buffer - it's directly driven by the CPLD. There are a lot of resistors there but fortunately they are all the same value.
For anyone who wants to attempt to build this thing I can supply preprogrammed chips for AU$9 and resistors, wire, etc for an extra AU$6. International ppd. Email: eviltim.optusnet@com@au
I don't know if the pinouts of the left side (pins 1-12) of the VDP and MAV DACs found in NTSC N64s match those of the DENC. It would be good if someone could check this.
For anyone who wants to attempt to build this thing I can supply preprogrammed chips for AU$9 and resistors, wire, etc for an extra AU$6. International ppd. Email: eviltim.optusnet@com@au
I don't know if the pinouts of the left side (pins 1-12) of the VDP and MAV DACs found in NTSC N64s match those of the DENC. It would be good if someone could check this.
Title: Nintendo64 RGB DAC
Post by: Moosmann on January 29, 2007, 05:24:23 AM
Post by: Moosmann on January 29, 2007, 05:24:23 AM
Great work :)
Double You in Germany offer this mod 9 years ago. However, the quality from the Double You Mod is much badder, compare to the old VDC-NUS RGB mod, because you have some colorglitches. I hope your mod works better
Here`s the connection from the Double You mod on a newer N64.
Bye Markus
Double You in Germany offer this mod 9 years ago. However, the quality from the Double You Mod is much badder, compare to the old VDC-NUS RGB mod, because you have some colorglitches. I hope your mod works better
Here`s the connection from the Double You mod on a newer N64.
Bye Markus
Title: Nintendo64 RGB DAC
Post by: viletim! on January 29, 2007, 05:31:39 PM
Post by: viletim! on January 29, 2007, 05:31:39 PM
The quality is excelent. Take a look at some photos of goldeneye (http://members.optusnet.com.au/stellalist/n64rgb/).
I was wondering what the double you mod looked like... It's interesting that it's powered from 5 volts (that poor little regulator must get hot) instead of 3.3 volts.
I was wondering what the double you mod looked like... It's interesting that it's powered from 5 volts (that poor little regulator must get hot) instead of 3.3 volts.
Title: Nintendo64 RGB DAC
Post by: Moosmann on January 30, 2007, 06:39:17 AM
Post by: Moosmann on January 30, 2007, 06:39:17 AM
I want to buy 4 N64 Chips (without resistors). I habe a Board with an "AVDC-NUS" IC here.
Bye Markus
Bye Markus
Title: Nintendo64 RGB DAC
Post by: sebi1000 on January 30, 2007, 09:59:19 PM
Post by: sebi1000 on January 30, 2007, 09:59:19 PM
Hey Moosmann, please contact me.
I�m from Germany, if we order the chips together we can save money.
sebi1000@web.de
Thanks!
I�m from Germany, if we order the chips together we can save money.
sebi1000@web.de
Thanks!
Title: Nintendo64 RGB DAC
Post by: viletim! on January 30, 2007, 11:04:28 PM
Post by: viletim! on January 30, 2007, 11:04:28 PM
Moosmann,
No problem. I'll order some chips at the end of the week and i'll let you know when I have them (it usualy takes a couple of weeks for them to arrive). Could you take a photo of the AVDC-NUS DAC? I'd like to add it to my pinouts collection.
No problem. I'll order some chips at the end of the week and i'll let you know when I have them (it usualy takes a couple of weeks for them to arrive). Could you take a photo of the AVDC-NUS DAC? I'd like to add it to my pinouts collection.
Title: Nintendo64 RGB DAC
Post by: Guest on January 31, 2007, 03:21:22 AM
Post by: Guest on January 31, 2007, 03:21:22 AM
@viletim!:
I have a question: It is possible to programm the Chip that I don`t need the resistors ? :)
What is the reason, that you use so many 560 Ohm resistors instead seven resistors each color e.g. 1K, 2K, 4K, 8K and so on.. like the 3DO RGB Mod ?
Bye Markus
I have a question: It is possible to programm the Chip that I don`t need the resistors ? :)
What is the reason, that you use so many 560 Ohm resistors instead seven resistors each color e.g. 1K, 2K, 4K, 8K and so on.. like the 3DO RGB Mod ?
Bye Markus
Title: Nintendo64 RGB DAC
Post by: RARusk on January 31, 2007, 01:30:34 PM
Post by: RARusk on January 31, 2007, 01:30:34 PM
Here's an interesting question: Can you use the DAC inside the GameCube Component Video Cable in place of what you have there? Or do the digital signals not match up?
Title: Nintendo64 RGB DAC
Post by: viletim! on January 31, 2007, 10:02:40 PM
Post by: viletim! on January 31, 2007, 10:02:40 PM
Moosmann,
The resistors are in an R2R configuation (as opposed to binary weighted) to get better accuracy. A binary weighted DAC would use fewer resistors but they would all be funny values (so you'd have to use two in parallel) and be less accurate (using 1% resistors) compared to an R2R. The optimal values for 7 bits binary weighted go something like: 700, 1400, 2800, etc
And yes, you need some resistors unless you you're happy with 3-bit RGB video :)
RARusk,
I don't have any Gamecube stuff so I can't really say. From a distance it does appear that both DACs operate similarly, with the Gamecube one having an extra bit or two. The GC DAC can output RGB and YUV but does anyone know which is the native format?
The resistors are in an R2R configuation (as opposed to binary weighted) to get better accuracy. A binary weighted DAC would use fewer resistors but they would all be funny values (so you'd have to use two in parallel) and be less accurate (using 1% resistors) compared to an R2R. The optimal values for 7 bits binary weighted go something like: 700, 1400, 2800, etc
And yes, you need some resistors unless you you're happy with 3-bit RGB video :)
RARusk,
I don't have any Gamecube stuff so I can't really say. From a distance it does appear that both DACs operate similarly, with the Gamecube one having an extra bit or two. The GC DAC can output RGB and YUV but does anyone know which is the native format?
Title: Nintendo64 RGB DAC
Post by: Moosmann on February 01, 2007, 05:59:40 AM
Post by: Moosmann on February 01, 2007, 05:59:40 AM
Thanks for your information. Is this the reason that the Double You mod don`t work correctly ? I think I will make some experiments with the resistors when I received your Chips and compare with the old rgb mod from a japanese N64
BTW: The RGB Chip with the resistors looks like an animal :)
Bye Markus
BTW: The RGB Chip with the resistors looks like an animal :)
Bye Markus
Title: Nintendo64 RGB DAC
Post by: Moosmann on February 03, 2007, 05:14:34 AM
Post by: Moosmann on February 03, 2007, 05:14:34 AM
QuoteHere's an interesting question: Can you use the DAC inside the GameCube Component Video Cable in place of what you have there? Or do the digital signals not match up?
@RARusk:
I just tried something, D0-D7 and D8-D1 or double soldering D7 & D8 (because the N64 have only 7 data lines) but it doesn`t work at the moment.
Bye Markus
Title: Nintendo64 RGB DAC
Post by: RARusk on February 03, 2007, 02:21:14 PM
Post by: RARusk on February 03, 2007, 02:21:14 PM
Pretty funky looking. I am assuming that you have RGB modified your GameCube cable, yes? I am going to guess that because there is an extra line of data that using the GameCube DAC chip may not work on the N64 after all. But keep plugging away. It could still work if the proper wiring can be figured out.
As for Viletim!, you really should get a GameCube and figure out it's digital signals. You might be the best person here to sort out if you can use another DAC with the GC instead of paying exorbant prices on Ebay for the GC Component Video cables. I consider myself very lucky to own two of the cables including the one I have modified for RGB use. It would be sweet to have an alternative chip to use. And perhaps another one to use on the N64 as well.
As for Viletim!, you really should get a GameCube and figure out it's digital signals. You might be the best person here to sort out if you can use another DAC with the GC instead of paying exorbant prices on Ebay for the GC Component Video cables. I consider myself very lucky to own two of the cables including the one I have modified for RGB use. It would be sweet to have an alternative chip to use. And perhaps another one to use on the N64 as well.
Title: Nintendo64 RGB DAC
Post by: viletim! on February 04, 2007, 12:30:47 PM
Post by: viletim! on February 04, 2007, 12:30:47 PM
Moosmann,
Interesting... Did you try to switch the DAC between RGB and YUV?
I'll see if I can find a cheap Gamecube to experement on...
Interesting... Did you try to switch the DAC between RGB and YUV?
I'll see if I can find a cheap Gamecube to experement on...
Title: Nintendo64 RGB DAC
Post by: radorn on February 05, 2007, 04:58:24 PM
Post by: radorn on February 05, 2007, 04:58:24 PM
Moosmann
As RARusk and viletim! asked, did you RGB-mod that cable?
I don't see the resistor that I've seen on the mods arround the net, it goes in a pin on the DAC that falls exactly on the upper left part as seen on the picture.
Maybe you implemented it differently, so I'm just guessing.
Still, I'm not so sure it would make a big difference.
I mean. It should'nt matter the format the dac is outputting, right? If the input is right, the output, whether RGB or YPbPr, given it is connected to the right equipment, should look correct, right?
Im not as experienced as any of you so don't mind much what I say. I was just especulating.
Anyway, viletim, I would be interested in your invention.
I live in Spain. How much would you need for each? I don't know yet how many I would get because a couple of friends of might be interested too.
it would be 4-5 as much. I pay upfront, of course, so there're no trust issues
As RARusk and viletim! asked, did you RGB-mod that cable?
I don't see the resistor that I've seen on the mods arround the net, it goes in a pin on the DAC that falls exactly on the upper left part as seen on the picture.
Maybe you implemented it differently, so I'm just guessing.
Still, I'm not so sure it would make a big difference.
I mean. It should'nt matter the format the dac is outputting, right? If the input is right, the output, whether RGB or YPbPr, given it is connected to the right equipment, should look correct, right?
Im not as experienced as any of you so don't mind much what I say. I was just especulating.
Anyway, viletim, I would be interested in your invention.
I live in Spain. How much would you need for each? I don't know yet how many I would get because a couple of friends of might be interested too.
it would be 4-5 as much. I pay upfront, of course, so there're no trust issues
Title: Nintendo64 RGB DAC
Post by: NFG on February 05, 2007, 05:19:25 PM
Post by: NFG on February 05, 2007, 05:19:25 PM
You certainly don't need a resistor, I've never used one in all my VGA/RGB cable mods. It is only there for a little extra security against frying stuff - but that's a pretty dubious as well.
Title: Nintendo64 RGB DAC
Post by: radorn on February 05, 2007, 06:51:38 PM
Post by: radorn on February 05, 2007, 06:51:38 PM
QuoteYou certainly don't need a resistor, I've never used one in all my VGA/RGB cable mods. It is only there for a little extra security against frying stuff - but that's a pretty dubious as well.oh, I didn't know that.
I don't want to switch focus of the thread to gamecube stuff but, appart from security, is there any difference using it or not?
Some people says the GC VGA mod has quality issues, like bleeding red or something (can't quite remember what it was). Maybe a slighty weak signal.
Could that have to do with using or not a resistor? Just wondering.
Title: Nintendo64 RGB DAC
Post by: Moosmann on February 06, 2007, 04:41:40 AM
Post by: Moosmann on February 06, 2007, 04:41:40 AM
Yes, I use the resistor (2 wires, isolation with an black heat shrink sleeve) for RGB.
Bye Markus
Bye Markus
Title: Nintendo64 RGB DAC
Post by: RARusk on February 06, 2007, 02:15:42 PM
Post by: RARusk on February 06, 2007, 02:15:42 PM
"Some people says the GC VGA mod has quality issues, like bleeding red or something (can't quite remember what it was). Maybe a slighty weak signal. Could that have to do with using or not a resistor? Just wondering."
I've never had any issues with the GameCube RGB mod. It looks great in 15Khz (interlaced) and 31Khz (progressive) scan modes.
I've never had any issues with the GameCube RGB mod. It looks great in 15Khz (interlaced) and 31Khz (progressive) scan modes.
Title: Nintendo64 RGB DAC
Post by: radorn on April 03, 2007, 10:34:02 PM
Post by: radorn on April 03, 2007, 10:34:02 PM
Hi.
Now that the digital video format of the n64 is "decoded", would it be possible to make a DVI/HDMI interface? I guess it would be.
Of course I'm not talking about feasibility, or cost (wich would be pretty high I'm afraid), and I'm aware that interest might not be enough; as much as I love my n64 I come to recognize it's graphics aren't that clean and crisp due to not so well used smoothing techiques, so maybe there wouldn't be too much of a benefit from mantaining video in digital form for, say, a pixel based display such as LCD or LED, without any analog transition, mainly because of the horizontal lines being converted from digital to analog and sampled back to digital, with probable misalignement respect of the original pixels as analog video doesn't really have pixels.
Never mind, I'm just daydreaming. I have yet to install this mod as I received it from viletim yesterday. I'll comment on it once I have it running, but that won't be for a while as I found myself really busy suddenly.
Now that the digital video format of the n64 is "decoded", would it be possible to make a DVI/HDMI interface? I guess it would be.
Of course I'm not talking about feasibility, or cost (wich would be pretty high I'm afraid), and I'm aware that interest might not be enough; as much as I love my n64 I come to recognize it's graphics aren't that clean and crisp due to not so well used smoothing techiques, so maybe there wouldn't be too much of a benefit from mantaining video in digital form for, say, a pixel based display such as LCD or LED, without any analog transition, mainly because of the horizontal lines being converted from digital to analog and sampled back to digital, with probable misalignement respect of the original pixels as analog video doesn't really have pixels.
Never mind, I'm just daydreaming. I have yet to install this mod as I received it from viletim yesterday. I'll comment on it once I have it running, but that won't be for a while as I found myself really busy suddenly.
Title: Nintendo64 RGB DAC
Post by: Moosmann on April 06, 2007, 07:11:18 PM
Post by: Moosmann on April 06, 2007, 07:11:18 PM
I installed a DAC from viletim! into an first PAL-N64 with "DENC" PPU. The quality is great. I haven`t compared the quality at the same time with the old NTSC VDC-Mod, but I think the quality is the same or a little better.
To get the best result, I use the S-Video Y-Signal instead composite video.
Greetings Markus
To get the best result, I use the S-Video Y-Signal instead composite video.
Greetings Markus
Title: Nintendo64 RGB DAC
Post by: davidleeroth on April 18, 2007, 09:56:34 PM
Post by: davidleeroth on April 18, 2007, 09:56:34 PM
Took a while to get started but I completed the mod yesterday and got it working right off the bat. (A rare occasion in my case)
I'll give it a try using SMD resistors next time though, my hands didn't like the twisting part that much. :P
I mounted it on a PAL-DENC and the quality is great, there seems to be a little less noise when compared to the old NTSC mod. The difference is minimal though and I had to get really close to see it, surely not something you'd notice when playing.
Ur da man viletim!
I'll give it a try using SMD resistors next time though, my hands didn't like the twisting part that much. :P
I mounted it on a PAL-DENC and the quality is great, there seems to be a little less noise when compared to the old NTSC mod. The difference is minimal though and I had to get really close to see it, surely not something you'd notice when playing.
Ur da man viletim!
Title: Nintendo64 RGB DAC
Post by: Moosmann on April 19, 2007, 06:33:46 AM
Post by: Moosmann on April 19, 2007, 06:33:46 AM
Quotequality is great, there seems to be a little less noise when compared to the old NTSC mod.
You`re right. But the problem is not from the rgb dac.
Check the RGB Cable whether it have a 75-Ohm resistor from Video (scart Pin 20) to ground. Or take the Y-Signal from S-Video as Sync instead composite Video.
The best way is to use an original Super Famicom RGB Cable with 75-Ohm resistor to ground.
You can also use 280 Ohm resistors instead the 2 parallel wired 560 Ohm resistors.
Greetings Markus
Title: Nintendo64 RGB DAC
Post by: davidleeroth on April 19, 2007, 05:40:43 PM
Post by: davidleeroth on April 19, 2007, 05:40:43 PM
I used the luma for sync, I think the noise has more to do with my "craftmanship" on the old mod. But as said, I can't tell the difference unless I pull my nose against the monitor.
On a not-so-related note, does anyone know how the region lockout chip works? I had region modded the console before and as I was working with the RGB mod one of the wires from the chip came off. I tried it just for fun and all the games booted to the title screen but froze in-game...
On a not-so-related note, does anyone know how the region lockout chip works? I had region modded the console before and as I was working with the RGB mod one of the wires from the chip came off. I tried it just for fun and all the games booted to the title screen but froze in-game...
Title: Nintendo64 RGB DAC
Post by: radorn on April 27, 2007, 10:23:50 AM
Post by: radorn on April 27, 2007, 10:23:50 AM
QuoteOn a not-so-related note, does anyone know how the region lockout chip works? I had region modded the console before and as I was working with the RGB mod one of the wires from the chip came off. I tried it just for fun and all the games booted to the title screen but froze in-game...The PIF-NUS is not only a lockout chip but it also takes care of the controllers and stuff like that (PIF stands for Peripheral InterFace, I read somewhere). So actually the CIC chips seem to be considered peripherals on N64's architecture. That may have something to do with what you are experiencing, but then again, I'm sure there are a lot people that can tell you better about this.
Title: Nintendo64 RGB DAC
Post by: Dr.Wily on April 29, 2007, 10:24:17 PM
Post by: Dr.Wily on April 29, 2007, 10:24:17 PM
If you try to get a n64 devkit you will be surprised to note this model has built in RGB suport. I don't know how is wired, but it is probably interesting to open this kind of unit.
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 06, 2007, 10:52:42 PM
Post by: Barkuti on July 06, 2007, 10:52:42 PM
Hi guys, just googleing a bit for N64 stuff cos I recently cleaned a bit of the dust over it and... L@@k at this!
I'll be asking viletim for a kit asap!
How are you doing with this mod? One of the most annoying things about 4-player gaming was the tremendous blurriness over composite video in split screen... Did anyone tested a hi-res shooter like PD this way? The improvement here should be HUGE, isn't it?
Cheers
(first post btw!) :)
I'll be asking viletim for a kit asap!
How are you doing with this mod? One of the most annoying things about 4-player gaming was the tremendous blurriness over composite video in split screen... Did anyone tested a hi-res shooter like PD this way? The improvement here should be HUGE, isn't it?
Cheers
(first post btw!) :)
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 26, 2007, 12:30:57 PM
Post by: Barkuti on July 26, 2007, 12:30:57 PM
Hello again people,
Last friday 20th I received Tim's kit, although I've not managed to to install it yet due to time constraints and other little issues.
First, Tim sent me 56 out of the 60 resistors used by the circuit, maybe the cat ate those 4 missing ones :lol: ; 58 would have been enough, as R20 may be left common for all RGB resistor DACs, but alas...
Yesterday I had to make a quick trip to the city so I dropped by an electronics hardware store and purchased a couple dozens of standard 5% resistors (precision ones not available); after sorting out the pack with a multimeter and picking the cherry the problem is solved. I also purchased a socket for the sake of it.
Ok, enough talk. :P
The problem for me now is trying to remove the N64's heatsink. Those screws are soooo tight it's like a nightmare made real. Maybe I'm not using a big enough Philips head (I hate Philips heads), but God those screws are so tight... I've already broken a cheap flathead tip and 4 or 5 of those screwheads are damaged... Only removed one screw so far (first one and wasn't hard :huh: ).
I've sprayed some multi-purpose oil around the screws, waiting for it to settle overnight...
I'll see what can I do tomorrow.
Tips are welcome.
Cheers
Last friday 20th I received Tim's kit, although I've not managed to to install it yet due to time constraints and other little issues.
First, Tim sent me 56 out of the 60 resistors used by the circuit, maybe the cat ate those 4 missing ones :lol: ; 58 would have been enough, as R20 may be left common for all RGB resistor DACs, but alas...
Yesterday I had to make a quick trip to the city so I dropped by an electronics hardware store and purchased a couple dozens of standard 5% resistors (precision ones not available); after sorting out the pack with a multimeter and picking the cherry the problem is solved. I also purchased a socket for the sake of it.
Ok, enough talk. :P
The problem for me now is trying to remove the N64's heatsink. Those screws are soooo tight it's like a nightmare made real. Maybe I'm not using a big enough Philips head (I hate Philips heads), but God those screws are so tight... I've already broken a cheap flathead tip and 4 or 5 of those screwheads are damaged... Only removed one screw so far (first one and wasn't hard :huh: ).
I've sprayed some multi-purpose oil around the screws, waiting for it to settle overnight...
I'll see what can I do tomorrow.
Tips are welcome.
Cheers
Title: Nintendo64 RGB DAC
Post by: NFG on July 26, 2007, 04:45:14 PM
Post by: NFG on July 26, 2007, 04:45:14 PM
Go get a proper screwdriver. With a proper tool those screws come out with no effort at all.
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 26, 2007, 06:48:04 PM
Post by: Barkuti on July 26, 2007, 06:48:04 PM
Yes, just got a wider head with flatter tip, and got those things removed. The oil worked wonders btw. Each screw made a distinctive "clack" sound upon turning.
Wow, the mainboard is sandwiched between a couple metal plates :huh: (Making a bulletproof game console?). I do not see a good reason to put the upper one back in place; also, it's installed below the heatsink and that's not good for heat transfer (Nintendo designers must had been smoking crack while coming up with this).
More updates once I recover some sleep and get time for the mod.
Cheers
Wow, the mainboard is sandwiched between a couple metal plates :huh: (Making a bulletproof game console?). I do not see a good reason to put the upper one back in place; also, it's installed below the heatsink and that's not good for heat transfer (Nintendo designers must had been smoking crack while coming up with this).
More updates once I recover some sleep and get time for the mod.
Cheers
Title: Nintendo64 RGB DAC
Post by: viletim on July 26, 2007, 11:16:33 PM
Post by: viletim on July 26, 2007, 11:16:33 PM
Barkuti,
Sorry about the missing resistors. I actually found a packet of 560 ohm resistors floating around the other day and thought: I know where these are supposed to be...
I have just recently sourced some 280 ohm resistors which would bring the count down to 42. I'll send you some if you like (and have the patience to wait a week for them).
BTW, you definately need an R20 for each DAC.
Sorry about the missing resistors. I actually found a packet of 560 ohm resistors floating around the other day and thought: I know where these are supposed to be...
I have just recently sourced some 280 ohm resistors which would bring the count down to 42. I'll send you some if you like (and have the patience to wait a week for them).
BTW, you definately need an R20 for each DAC.
Title: Nintendo64 RGB DAC
Post by: lameboyadvance on July 27, 2007, 02:38:40 PM
Post by: lameboyadvance on July 27, 2007, 02:38:40 PM
Firstly, excellent work viletim! :D
I (along with others apparently) have been waiting for a decent RGB mod for the DENC/etc chips. :)
...With these 280 ohm resistors, how does that change your circuit diagram? All the 560s change to 280, and the ones in parallel (R8-9, R10-11 etc) are combined into a single resistor?
Also, I noticed that you're selling CPLDs for $9 and resisitors/misc for $6. Does this change affect the price?
I (along with others apparently) have been waiting for a decent RGB mod for the DENC/etc chips. :)
...With these 280 ohm resistors, how does that change your circuit diagram? All the 560s change to 280, and the ones in parallel (R8-9, R10-11 etc) are combined into a single resistor?
Also, I noticed that you're selling CPLDs for $9 and resisitors/misc for $6. Does this change affect the price?
Title: Nintendo64 RGB DAC
Post by: viletim on July 27, 2007, 08:27:35 PM
Post by: viletim on July 27, 2007, 08:27:35 PM
lameboyadvance,
The 280 R replaces two 560 Rs in parallel so the circuit would look like:
Price of the bits remains the same.
The 280 R replaces two 560 Rs in parallel so the circuit would look like:
Code Select
. 0 ---2R--+--2R---+
. | |
. R ---GND
. |
. 1 ---2R--+ R=280
. | 2R=560
. R
. |
. 2 ---2R--+
. | etc...
.~~~~~~~~~~~~~~~~~~~~~~~~
. |
. 6 ---2R--+----> vid outPrice of the bits remains the same.
Title: Nintendo64 RGB DAC
Post by: Drewman21 on July 28, 2007, 01:32:27 AM
Post by: Drewman21 on July 28, 2007, 01:32:27 AM
I hate to ask as I am interested in this mod but it seems pretty involved. Tim would you post some pictures or a short walk though of what is need to assemble your mod? And the typical dumb question that I have to ask as I have all ready bought the parts for a few of the MMMonkey RGB mods. How much better is your mod over just the plain old amp he came up with? Thanks.
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 28, 2007, 01:03:56 PM
Post by: Barkuti on July 28, 2007, 01:03:56 PM
Hi again guys,
Just dropped by to say this mod is certainly painful. A PCB would really help for suckers like me with 1.5 mm tip soldering irons. I've already dug 3 little holes on the socket's plastic :ph34r: (man the socket was a GOOD idea imho).
A little question: Is the mod going to work fine just soldering the RGB outs to the 1, 2 & 4 pins on the multi-out? I mean, it'll be taking csync from the composite signal, everything ok? I just ask this because Moosman was saying the optimal RGB cable uses a 75 Ohm resistor from pin 20 to ground on the SCART, I've measured mine (a cheap one I bought for a GameCube) and it doesn't seems to have it (infinite resistance from pin 20 to shield with disconnected cable). �?
Cheers
Just dropped by to say this mod is certainly painful. A PCB would really help for suckers like me with 1.5 mm tip soldering irons. I've already dug 3 little holes on the socket's plastic :ph34r: (man the socket was a GOOD idea imho).
A little question: Is the mod going to work fine just soldering the RGB outs to the 1, 2 & 4 pins on the multi-out? I mean, it'll be taking csync from the composite signal, everything ok? I just ask this because Moosman was saying the optimal RGB cable uses a 75 Ohm resistor from pin 20 to ground on the SCART, I've measured mine (a cheap one I bought for a GameCube) and it doesn't seems to have it (infinite resistance from pin 20 to shield with disconnected cable). �?
Cheers
Title: Nintendo64 RGB DAC
Post by: viletim on July 28, 2007, 03:19:51 PM
Post by: viletim on July 28, 2007, 03:19:51 PM
Drewman21,
If you find that the Assembly Procedure (http://members.optusnet.com.au/eviltim/n64rgb/assembly.html) isn't detailed enough for you then you should probably give this one a miss.
Barkuti,
That's the way mine's wired up. Works well. The extra 75 ohm resistor in the cable is only required if you intend to actualy watch the composite signal. If you're sure it's not in the cable (better of open up the SCART end and take a look) then you can just solder it into either the cable or the console.
I don't see how a socket would make assembly any easier. I would have thought it would make it even more arkward with it's double row pin arangement.
I did consider makeing a PCB but it would either be big with lots of holes or small and use SMD resistors. I hate drilling holes so that would mean I'd get them produced professionally and have all the problems that go along with that (minimum order, expensive, etc). If I were to produce an all SMD version then people would whinge about the parts being too small and hard to solder. The floaty resistor method is the best - good soldering practice too!
If you find that the Assembly Procedure (http://members.optusnet.com.au/eviltim/n64rgb/assembly.html) isn't detailed enough for you then you should probably give this one a miss.
Barkuti,
That's the way mine's wired up. Works well. The extra 75 ohm resistor in the cable is only required if you intend to actualy watch the composite signal. If you're sure it's not in the cable (better of open up the SCART end and take a look) then you can just solder it into either the cable or the console.
I don't see how a socket would make assembly any easier. I would have thought it would make it even more arkward with it's double row pin arangement.
I did consider makeing a PCB but it would either be big with lots of holes or small and use SMD resistors. I hate drilling holes so that would mean I'd get them produced professionally and have all the problems that go along with that (minimum order, expensive, etc). If I were to produce an all SMD version then people would whinge about the parts being too small and hard to solder. The floaty resistor method is the best - good soldering practice too!
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 29, 2007, 02:33:27 PM
Post by: Barkuti on July 29, 2007, 02:33:27 PM
Greetings,
I've made a dirty PCB design for standard size components + socket. Started to draw it with "ExpressPCB" (one of those free proggies companies make to lure customers, first link in google), and later noticed the software assumes you to be drawing the layout viewed from the component side; I did the drawing with the "solder side" view in mind, so it came up inverted and the prog can't make the flip. What a crap. Well, anyways it served the purpose. Take a look at the attached jpg file I made (only export format supported is by the software is DXF -Autocad?-).
Target size is 2.6 x 1.9 inches (around 66 x 48.3 mm), which is just a tad wider than the heatsink's inner width (at 44 mm), and a bit longer (just 6 mm) than the lower opened central section; a couple of pliers bites at the corners solves the problem. :rolleyes:
This is intended to make a single sided copper clad board. You print the drawing and transfer it to the board with carbon copy paper with a ballpen/pencil etc.; just the edges of course. Then with an alcohol based ink permanent marker the tracks are drawn/filled.
What I'm describing is a simple old method my brother teached me 20 years ago when he was studying electronics. The developing was made inmersing the board in "Sal fumante" (a 25% dissolution of HCl in water) and then spurting hydrogen peroxide over it (100-110 vol dissolutions, 30 to 33%), until the only thing remaining were the painted tracks.
For finishing, a good fresh water wash, alcohol to remove the ink, and a quick check for imperfections for fixup. The method may be somewhat tricky with the thin tracks we're using here.
Ok, this is a dirty job (OMG the picture background is black! :wacko: ). If anyone has a better software to make this at least half of the work is done.
Cheers
I've made a dirty PCB design for standard size components + socket. Started to draw it with "ExpressPCB" (one of those free proggies companies make to lure customers, first link in google), and later noticed the software assumes you to be drawing the layout viewed from the component side; I did the drawing with the "solder side" view in mind, so it came up inverted and the prog can't make the flip. What a crap. Well, anyways it served the purpose. Take a look at the attached jpg file I made (only export format supported is by the software is DXF -Autocad?-).
Target size is 2.6 x 1.9 inches (around 66 x 48.3 mm), which is just a tad wider than the heatsink's inner width (at 44 mm), and a bit longer (just 6 mm) than the lower opened central section; a couple of pliers bites at the corners solves the problem. :rolleyes:
This is intended to make a single sided copper clad board. You print the drawing and transfer it to the board with carbon copy paper with a ballpen/pencil etc.; just the edges of course. Then with an alcohol based ink permanent marker the tracks are drawn/filled.
What I'm describing is a simple old method my brother teached me 20 years ago when he was studying electronics. The developing was made inmersing the board in "Sal fumante" (a 25% dissolution of HCl in water) and then spurting hydrogen peroxide over it (100-110 vol dissolutions, 30 to 33%), until the only thing remaining were the painted tracks.
For finishing, a good fresh water wash, alcohol to remove the ink, and a quick check for imperfections for fixup. The method may be somewhat tricky with the thin tracks we're using here.
Ok, this is a dirty job (OMG the picture background is black! :wacko: ). If anyone has a better software to make this at least half of the work is done.
Cheers
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 29, 2007, 02:39:07 PM
Post by: Barkuti on July 29, 2007, 02:39:07 PM
Mmm forgot to say, the outer column/row resistors should be 280 Ohm, except the ones I marked as "R20".
Title: Nintendo64 RGB DAC
Post by: Barkuti on July 30, 2007, 02:07:00 PM
Post by: Barkuti on July 30, 2007, 02:07:00 PM
Hi,
Just finished the mod; tested with success (well, at first I thought I had screwed up something as I was only seeing a black screen :ph34r: , but quickly noticed my expansion pak wasn't back in so the RAMBUS had no termination).
I'm sure I'll enjoy it a lot when plugged to my arcade monitor or a CRT TV, but testing it on my kitchen's LCD TV shows a way too blocky image, also the colours look somewhat grainy while in motion in certain games (for example in Mario Tennis' intro). Yeah, I know, LCD's suck.
Again, awesome job Viletim.
BTW, I was thinking on using some hotglue over the chips' contacts/socket legs/etc. to firmly fix everything in place. Is this a good idea?
Cheers
Just finished the mod; tested with success (well, at first I thought I had screwed up something as I was only seeing a black screen :ph34r: , but quickly noticed my expansion pak wasn't back in so the RAMBUS had no termination).
I'm sure I'll enjoy it a lot when plugged to my arcade monitor or a CRT TV, but testing it on my kitchen's LCD TV shows a way too blocky image, also the colours look somewhat grainy while in motion in certain games (for example in Mario Tennis' intro). Yeah, I know, LCD's suck.
Again, awesome job Viletim.
BTW, I was thinking on using some hotglue over the chips' contacts/socket legs/etc. to firmly fix everything in place. Is this a good idea?
Cheers
Title: Nintendo64 RGB DAC
Post by: Drewman21 on July 31, 2007, 02:15:10 AM
Post by: Drewman21 on July 31, 2007, 02:15:10 AM
Very cool. Still wondering how this compares to the MMonkey amp mod for video quality. Anyone have any thoughts?
Tim could you let me know the cost of one of your kits sent to the states with shipping? If you have my address still that would be cool. I have a extra n64 that I could do up with it. Thanks man!
Tim could you let me know the cost of one of your kits sent to the states with shipping? If you have my address still that would be cool. I have a extra n64 that I could do up with it. Thanks man!
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 01, 2007, 09:22:11 PM
Post by: Barkuti on August 01, 2007, 09:22:11 PM
A little update on this topic.
After something more than the usual quick test to check if it works, I've noticed the screen offset isn't quite properly set with the RGB output. No problem with composite, but through Viletim's DAC on my machine the screen is noticeably shifted to the left; so much, that even using the "screen adjustment" option in Smash Bros and moving the rendering area all the way to the right, it doesn't becomes centered. :o
Of course, this may not be so much of a problem in a monitor, but on TVs it is no doubt since you can't count on making display shift adjustments.
I wonder if may I have done something wrong. Hope Viletim knows the answer.
�Is there any solution or workaround for this?
Cheers
After something more than the usual quick test to check if it works, I've noticed the screen offset isn't quite properly set with the RGB output. No problem with composite, but through Viletim's DAC on my machine the screen is noticeably shifted to the left; so much, that even using the "screen adjustment" option in Smash Bros and moving the rendering area all the way to the right, it doesn't becomes centered. :o
Of course, this may not be so much of a problem in a monitor, but on TVs it is no doubt since you can't count on making display shift adjustments.
I wonder if may I have done something wrong. Hope Viletim knows the answer.
�Is there any solution or workaround for this?
Cheers
Title: Nintendo64 RGB DAC
Post by: Moosmann on August 02, 2007, 05:32:01 AM
Post by: Moosmann on August 02, 2007, 05:32:01 AM
It`s normal with every rgb connection.
I sold "RGB Shifter" (in order to adjust RGB to left/right) in the last years ago, but at the moment I do no longer sold these units. Maybe I will make an update in my homepage with the circuit diagramm.
Greetings Markus
I sold "RGB Shifter" (in order to adjust RGB to left/right) in the last years ago, but at the moment I do no longer sold these units. Maybe I will make an update in my homepage with the circuit diagramm.
Greetings Markus
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 02, 2007, 09:46:44 AM
Post by: Barkuti on August 02, 2007, 09:46:44 AM
Mmm, I've read some info on this.
Seems the problem is related to the fact it's taking the sync signal from the composite video which, taking additional time to be generated and/or decoded, produces a delay that translates into a picture shift.
Possible solutions:
a) Take the composite sync signal from the PLCC, and put it into AV port's pin 9. The drawback is we would need to remove the composite video signal from it. Seems quite hard and messy to me, to say the least. We would also lose CVBS output, unless a switch would be installed.
B) Insert some delay circuitry on the RGB lines, giving the exact same delay to all 3 of them. Damn. Has anyone something to add here? Potential quality issues?
Suggestions?
Seems the problem is related to the fact it's taking the sync signal from the composite video which, taking additional time to be generated and/or decoded, produces a delay that translates into a picture shift.
Possible solutions:
a) Take the composite sync signal from the PLCC, and put it into AV port's pin 9. The drawback is we would need to remove the composite video signal from it. Seems quite hard and messy to me, to say the least. We would also lose CVBS output, unless a switch would be installed.
B) Insert some delay circuitry on the RGB lines, giving the exact same delay to all 3 of them. Damn. Has anyone something to add here? Potential quality issues?
Suggestions?
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 06, 2007, 12:23:56 PM
Post by: Barkuti on August 06, 2007, 12:23:56 PM
Hi fellas,
Decided to strip out the composite video signal from the output, and put composite sync on its place. Went the hard way and lifted DENC-NUS' pin 20 from the board (bye bye RF encoder). Next, soldered a wire from DAC's pin 27 to pin 9 on the multi-out.
Output's nice and centered now ^_^ . Maybe its me but I'd say the picture seems even crisper now. :huh:
Cheers
Decided to strip out the composite video signal from the output, and put composite sync on its place. Went the hard way and lifted DENC-NUS' pin 20 from the board (bye bye RF encoder). Next, soldered a wire from DAC's pin 27 to pin 9 on the multi-out.
Output's nice and centered now ^_^ . Maybe its me but I'd say the picture seems even crisper now. :huh:
Cheers
Title: Nintendo64 RGB DAC
Post by: viletim on August 06, 2007, 09:40:04 PM
Post by: viletim on August 06, 2007, 09:40:04 PM
Barkuti,
The !CSYNC will need a resistor in series to drop it down to nornal video level. About 220 ohms sholud do. Yes, I should have mentioned this before... If you've already put everything back together it's probably not worth bothering about.
The !CSYNC will need a resistor in series to drop it down to nornal video level. About 220 ohms sholud do. Yes, I should have mentioned this before... If you've already put everything back together it's probably not worth bothering about.
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 07, 2007, 10:20:52 AM
Post by: Barkuti on August 07, 2007, 10:20:52 AM
Hi Viletim,
What's the Vpp level of !CSYNC, and what's the csync level SCART TV's are expecting?
And what about monitors? I plan on building a patch cable for interfacing to an arcade monitor with D-sub connector; should the resistor be added in that case? Monitor supports standard VGA signal levels, including composite sync. Capacitors for the RGB lines, as in the SCART cable, are mandatory, right?
I've not blown up anything yet :lol: , I guess those TV circuits are built to withstand this kind of abuse, and probably much more...
Cheers
What's the Vpp level of !CSYNC, and what's the csync level SCART TV's are expecting?
And what about monitors? I plan on building a patch cable for interfacing to an arcade monitor with D-sub connector; should the resistor be added in that case? Monitor supports standard VGA signal levels, including composite sync. Capacitors for the RGB lines, as in the SCART cable, are mandatory, right?
I've not blown up anything yet :lol: , I guess those TV circuits are built to withstand this kind of abuse, and probably much more...
Cheers
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 07, 2007, 10:49:45 AM
Post by: Barkuti on August 07, 2007, 10:49:45 AM
Mmm, just read your MAME cabinet to SCART TV article Viletim (another awesome job btw). So 0.3 Vpp for csync, if !CSYNC is 1 Vpp, best resistor value should be ~180 Ohms, isn't it?
Still don't have a clue on the sync levels and/or impedances for monitors... when applicable.
Cheers
Still don't have a clue on the sync levels and/or impedances for monitors... when applicable.
Cheers
Title: Nintendo64 RGB DAC
Post by: viletim on August 07, 2007, 08:48:23 PM
Post by: viletim on August 07, 2007, 08:48:23 PM
Barkuti,
!CSYNC is 3.3Vpp with lots of current available (drops to 2.7v at ~25mA). It's a digital logic signal coming from a CMOS chip (the CPLD) powered from a 3.3v rail.
A composite video signal is usualy 1Vpp which is made up of 0.7Vpp of video and 0.3Vpp of sync. If you like to totaly adhere to the standard you can use a 680 resistor in series with !CSYNC to divide it down to 0.3Vpp with the TV's 75 ohm termination resistor. But as there's no video content, there's no harm in increasing the level of this videoless composite video signal up 1Vpp, especially as the CPLD outputs can easily provide the 13mA required. It's good for the signal to noise ratio. I chose 220 for a series resistor which, when loaded with 75R, will give you a healthy .8Vpp sync.
Arcade monitors are a bit different...they always require sync at TTL levels (max .4V = low, min 2.4V = high) which the CPLD output is compatible with.
!CSYNC is 3.3Vpp with lots of current available (drops to 2.7v at ~25mA). It's a digital logic signal coming from a CMOS chip (the CPLD) powered from a 3.3v rail.
A composite video signal is usualy 1Vpp which is made up of 0.7Vpp of video and 0.3Vpp of sync. If you like to totaly adhere to the standard you can use a 680 resistor in series with !CSYNC to divide it down to 0.3Vpp with the TV's 75 ohm termination resistor. But as there's no video content, there's no harm in increasing the level of this videoless composite video signal up 1Vpp, especially as the CPLD outputs can easily provide the 13mA required. It's good for the signal to noise ratio. I chose 220 for a series resistor which, when loaded with 75R, will give you a healthy .8Vpp sync.
Arcade monitors are a bit different...they always require sync at TTL levels (max .4V = low, min 2.4V = high) which the CPLD output is compatible with.
Title: Nintendo64 RGB DAC
Post by: Barkuti on August 13, 2007, 06:40:58 PM
Post by: Barkuti on August 13, 2007, 06:40:58 PM
Hi fellas,
Another little update on this topic. I've tested my N64 on the TV set that gave me colour picture problems with my ultra-dirty VGA-SCART cable (see here (http://nfggames.com/forum/index.php?showtopic=2895&view=findpost&p=19738)). Guess what? Same thing here. Green tinted picture.
In the first case sync signal was a HSYNC + VSYNC (both negative) mix, N64 uses !CSYNC from DAC through the RGB cable's 220�F cap on pin 20. The common point is, TTL signal levels in both cases.
Does this means that TV set doesn't likes that much sync signal? The greenish hue seems consistent over the picture colours, yet not present for black (intensity driven?).
Whatever the hell's this thing triggering inside the TV circuitry... :huh: I, for one, don't have a clue about what it is.
I'll have to drop that signal level and test it out.
Cheers
Another little update on this topic. I've tested my N64 on the TV set that gave me colour picture problems with my ultra-dirty VGA-SCART cable (see here (http://nfggames.com/forum/index.php?showtopic=2895&view=findpost&p=19738)). Guess what? Same thing here. Green tinted picture.
In the first case sync signal was a HSYNC + VSYNC (both negative) mix, N64 uses !CSYNC from DAC through the RGB cable's 220�F cap on pin 20. The common point is, TTL signal levels in both cases.
Does this means that TV set doesn't likes that much sync signal? The greenish hue seems consistent over the picture colours, yet not present for black (intensity driven?).
Whatever the hell's this thing triggering inside the TV circuitry... :huh: I, for one, don't have a clue about what it is.
I'll have to drop that signal level and test it out.
Cheers
Title: Re: Nintendo64 RGB DAC
Post by: jero32 on March 10, 2009, 04:53:16 AM
Post by: jero32 on March 10, 2009, 04:53:16 AM
Hey i'm new here. Sorry to bump this thread but I wanted to ask some questions.
First: has anyone tried this on a pal unit? (Seems like it should work anyway.)
Two: has anyone tried it with a "real" dac?
And can I use this to convert the c-sync: http://www.tkk.fi/Misc/Electronics/circuits/vga2tv/circuit.html ?
First: has anyone tried this on a pal unit? (Seems like it should work anyway.)
Two: has anyone tried it with a "real" dac?
And can I use this to convert the c-sync: http://www.tkk.fi/Misc/Electronics/circuits/vga2tv/circuit.html ?
Title: Re: Nintendo64 RGB DAC
Post by: jero32 on March 12, 2009, 07:01:09 AM
Post by: jero32 on March 12, 2009, 07:01:09 AM
Also what do you guys suggest is the best way to solder to the tiny pins. (I'll need lots of magnification) I have the 16 pin dac.
Title: Re: Nintendo64 RGB DAC
Post by: Jokeri on December 23, 2009, 05:25:59 PM
Post by: Jokeri on December 23, 2009, 05:25:59 PM
Sorry to pump up old topic, but just found this forum while searching PAL N64 RGB mod.
viletim: do you still have components for sale?
Picture quality on my PAL N64 is very blurry, and I would like to try your mod.
viletim: do you still have components for sale?
Picture quality on my PAL N64 is very blurry, and I would like to try your mod.
Title: Re: Nintendo64 RGB DAC
Post by: viletim on December 26, 2009, 07:24:42 PM
Post by: viletim on December 26, 2009, 07:24:42 PM
Jokeri,
I have enough parts left for two kits. Email me if you'd like one.
I have enough parts left for two kits. Email me if you'd like one.