fucked up N64 mod off from ebay

I did some testings, and was pleased by the result.

I see why Marshall was keen to stress that the HDMI output will only be as good as generated by the console and the game output. The reason will be for the same reasons I commented in my post today (with photos of image quality):

http://assemblergames.com/l/threads/new-multi-console-system-project.51352/page-2

 

Not really no. You don't take into consideration that the TV and upscaler does deinterlacing at all. With a proper scaler there would be no noticeable misaligned pixels If you take a look a the links I posted earlier it's very clear to see that scalers can look very different, and only very few properly supports 240p.

Besides, the HDMI mod will likely be lagfree. Which is definitely not the case when deinterlacing is involved.

 

Interesting read from what I read, and the units that seem to work well cost a lot of money. What is a cheap SCART or RGB unit that converts to HDMI with pretty perfect output, for retro systems, ie up to N64 or oven for later PS2/GameCube systems?

 

Yes unfortunately they are pretty expensive At the moment the XRGB-mini is the best choice, it does perfect 240p upscaling, and excellent 480i deinterlacing (for videogames). Unfortunately 480p is only decent at most, especially compared to other upscalers.

There's another unit in the works by a member on SHMUPS forum, that looks very interesting. It should end up being much cheaper than the XRGB-mini. But I expect it won't be suited for consoles that use a weird refresh-rate, ie. the Neo Geo CD which runs at roughtly 59.4Hz. But it will probably depend on your specific TV. I'm looking forward to it though, and I'm expecting the image quality to be slightly better than the XRGB-mini!

You can read about that one here:
http://shmups.system11.org/viewtopic.php?f=6&t=52158

 

Have you looked at scart to Hdmi upscalers on eBay, I belive they have a fully populated scart connector

So RGB and the like

 

That's exactly what I am using.

What is further interesting, is I think the slight imperfection with the upscaling I get on my N64 mod is actually the RGB mod not the SCART>HDMI converter, as on my 32" screen, the image looks the same via SCART or HDMI. Fortunately the imperfections are very minor. It is either how my television interprets the signal or the Okatus mod. When I mod other retro consoles i'll know as some of those have native RGB output so if the image it perfect it's the Otakus mod, if not it's the television - especially as it was more pronounced on the 32" television than my 65" television.

 

@bacteria
you signed up as modder for n64 hdmi too?
did you get the info mail yesterday, what do you think about the price ?

btw
I can not recommend otakus store stuff. they steal design from the community and sell it overpriced.
most designs of those pcbs and chips where invented and made from german community and those french bastards steal it and sell it
commercial.

the Pal n64 RGB pcb from zerberus or F_L_a_S_H cost 18€ already assembled, with ribbon cable and including shipping.
I order them monthly, they're fuckin awesome.

 

No, not signed up for the N64 HDMI unit, I am aware of the mod and will be interesting, how much is it?

Are the other RGB units for N64 better than the one Otakus sells? Links? Only reason I use it is it was the only one I was aware would work on UK PAL consoles for RGB output; would be good to know of a different source especially if better.

Experience I have of the Otakus one is it works and looks pretty good, even with a Chinese SCART > HDMI upscaler. The imperfections with some of the pixels not being accurate though - is that the upscaler HDMI or the Otakus unit?

 

What were you using for sync? I found that I experienced imperfections when I was using composite video sync. Switching to luma (no c-sync on my board revision) cleaned this up.

 

Does the Otakus one use the THS-amp, or is it the clone of Tim's DAC with all the resistors? I found both of them pretty similar in picture quality. There was some slight blurred pixels for me, on the XRGB-mini too. Nothing major, but I still wanted to sort it out.

The old fashioned transistor mod is a little bit better than the other two. I can get very sharp and even pixels with this, although it does require different settings than other 240p consoles, so I don't really bother and just play with the slight blur

Here two pictures that show the difference:
http://i40.photobucket.com/albums/e...CE-9891-740B24DD84E8_zpsnhdatzvc.jpg~original
http://i40.photobucket.com/albums/e...28-8406-60BEF0194608_zps0ojctv2d.jpg~original
- hopefully they'll show up in fullscreen for you.
The top one is the THS-amp and the bottom one is the transistor based one. If you look hard at the vertical line in the letter "A" in "MARIO", you can see that one is very slightly blurred compared to the other. That's it, that's the only difference in picture quality as far as I've seen. Decide for yourself if you think it's worth replacing your mod for this

Also here's a picture of the installed mod on mine, which is a US N64:
http://i40.photobucket.com/albums/e...F-234A-48D6-B8CC-8D8C3F38CE03_zpsmyhemmsr.jpg

 

Interesting. I've only ever used composite sync, so using luminance could possibly solve the above "issue" on the THS- and DAC-mod?

 

Tim's DAC has slightly softer edges because the RGB components are updated individually and not together. It's easy to fix (just put some extra latches into the signal path and strobe the whole lot out at once), but this means changing to a more expensive CPLD with more macrocells.

 

This is the Otakus one I used - pic below - would be good to know how it rates - comments? Tried the C-Sync line with luma before and composite, didn't see a difference, so used the C-Sync from the board itself (which I think looked the best as I recall).

 

It seems to have buffers driving the resistor ladders, which should help a bit with linearity, but it's hard to know if it still has the timing skew - the best clue would be how many macrocells there are in the CPLD, but they have sanded the number off so it's hard to tell. When I was looking at this, I thought it was possible to double latch the data with 6 bits per color component, but not with 7 bits - and that board appears to have 6 bit DACs on it, so it's possible that's what they are doing.

 

I have another of these, so looked at the chips - yes, the square chip has been sanded so can't see the lettering, but the rectangular chips say "4816P LF" "1-561" "B C1341" if that means anything to anyone.

All I know is it seems to give good RGB, as to some dot inaccuracies, it might be down to the television being used as my 65" screen gives better accuracy than the 32" one I have. At some point I need to compare SCART output vs HDMI upscale, if both look the same then it's either the Okatus or the fact the N64 is nearly 20 years old, and uses dated resolutions. If there is a noticable difference however then it will be the HDMI upscaler instead. One or the other; or as mentioned, using old electronics doesn't help - will be interesting when I put GameCube onto my project if that looks different, vs component as it gives me now.

 

Well, I just checked and the new version of Tim's RGB board is using a different CPLD - an Altera MAXII EPM240 - and that certainly does have enough logic to buffer everything and send it out on the same clock - he also specifically mentions that it has better timing than the previous version.

I would probably go for Tim's board, to be honest.

 

Link to Tim's board? Interested to hear more about it, and price.

 

Here it is:

http://etim.net.au/n64rgb/

It's AU $40 - about 20 quid.