PC Engine RGB jailbars, let us find a working solution

[RGB32E]

Betting money it's just another one similar to these two:

http://www.db-elec.com/home/News/dbgraf ... perational

http://www.neo-geo.com/forums/showthrea ... BoostMasta

So probably no need to wait.

How much money?

While both of these booster replacements look pretty sweet, aside from the hair-brained idea to use a 9 pin mini din output connector, it's just a customizable video and audio amp. Using a standard RGB encoder or a THS amp as found in these products will results in incorrect signal levels. While it "works" the picture is too bright, and black level isn't correct.

The memory backup capability of the one two is pretty cool. Perhaps these adapters could be modified to use Tim's kit.

[ApolloBoy]

aside from the hair-brained idea to use a 9 pin mini din output connector

???

It's small, supports both RGB and composite video, and cables for it are easy to get since it's the same connector used in the Genesis 2. How the fuck is it "hair-brained"?

[Pasky]

So quick to criticize other ideas while coming up with none of your own. The fact that it just plugs right in and works makes it brilliant. Not the correct levels in comparison to what? Most people don't care about having perfect color accuracy and most would probably agree the ths and ncs amplifiers are fine.

[RGB32E]

aside from the hair-brained idea to use a 9 pin mini din output connector

???

It's small, supports both RGB and composite video, and cables for it are easy to get since it's the same connector used in the Genesis 2.

For the units with an RGB encoder it perpetuates the design flaw of the Genesis 2 of not having 75 ohm resistors and 220uF caps in the system, resulting in cabling that will be subject to greater crosstalk.

For units with a 3 channel amp, it has resistors and caps already on the board, so using a Genesis 2 RGB cable would double up the resistors and capacitors in the cable. Hence, you'd have to remove the caps and resistors in the Genesis 2 RGB cable.

If anything, the Saturn 10 pin mini din could be an option.

I didn't mean any offense, it just doesn't make sense to use a modified (Y/C) Genesis 2 pinout IMHO.

[Artemio]

No need to be defensive about it. He is referring to standard video levels, what a CRT would expect in terms of voltages. The amp could be fitted inside any of these two, with the disadvantage of not being able to use a CD-ROM. Of course a passtrhough solution could be made so the CD-ROM could plug in the back of such a unit...

I'd be very glad to see a solution that cares about correct video levels.

Artemio: You mentioned the Otaku solution not working for you and your PCE Duo. Although I linked to that earlier, I haven't read the details. You mentioned C909 a few posts up. Perhaps thesteve's solution might help you out? It would be nice if it does. Admittedly, it would probably push the RGB mod to the Duo up higher on my console "to do list" as well.

I'll try and check it next week.

[RGB32E]

So quick to criticize other ideas while coming up with none of your own. The fact that it just plugs right in and works makes it brilliant. Not the correct levels in comparison to what? Most people don't care about having perfect color accuracy and most would probably agree the ths and ncs amplifiers are fine.

You certainly are quick to start jabbing away. Depending upon the model and cable you're using it wouldn't work right. Also, you can't really use an expansion port device to modify a Duo, can you?

[RGB32E]

No need to be defensive about it. He is referring to standard video levels, what a CRT would expect in terms of voltages. The amp could be fitted inside any of these two, with the disadvantage of not being able to use a CD-ROM. Of course a passtrhough solution could be made so the CD-ROM could plug in the back of such a unit...

I'd be very glad to see a solution that cares about correct video levels.

Exactly this.

[rtw]

Hard to use an IFU-30 with a PCB sticking out the back of the PCE, so I hope for something I can solder inside.

All the stuff I have bought from Tim in the past has been top notch

[Artemio]

Hard to use an IFU-30 with a PCB sticking out the back of the PCE, so I hope for something I can solder inside.

All the stuff I have bought from Tim in the past has been top notch

I meant for the plug solutions for the EXT port. Replacing the amp for Tim's.

And I agree, all his products are great.

[speedlolita]

I'll be interested to see this solution of tim's.

Very happy with my broken amp even so.

[viletim]

You're referring to my AV-DRIVER board.

It's a general purpose AV driver amplifier. 4 channels video, 2 channels audio, 1 channel sync. It works well in the PC Engine and an in other applications too. It will be available to buy soon, after I've finished the documentation.

[Pasky]

Very cool. Look forward to it. I wonder how it would fair in a super gun, especially for games like ninja baseball batman which are known to have lower video levels than the norm.

[ApolloBoy]

Hey Tim, do you know how your amp fares with the TMS9928 VDP by any chance? I've been constantly fiddling around with the component video mods on both my ColecoVision and SG-1000 II (which could be considered kludgey at best) and having a solution that would work with almost any display would be fantastic.

[viletim]

Very cool. Look forward to it. I wonder how it would fair in a super gun, especially for games like ninja baseball batman which are known to have lower video levels than the norm.

It should do a good job here. Only extra thing it needs a good quality multi gang (3+) potentiometer to adjust the video level (every PCB is a bit different). I bough a bag of 4 gang pots some time ago for this purpose, but the tolerance wasn't good enough. I'll see if I can get some samples from different suppliers to find something suitable.

Hey Tim, do you know how your amp fares with the TMS9928 VDP by any chance? I've been constantly fiddling around with the component video mods on both my ColecoVision and SG-1000 II (which could be considered kludgey at best) and having a solution that would work with almost any display would be fantastic.

Yes, it should work well there in theory. I have a Colecovision, I'll attempt it soon.

[ApolloBoy]

Yes, it should work well there in theory. I have a Colecovision, I'll attempt it soon.

Awesome, let me know how it turns out.

[leonk]

I finally got around to install "Broken"'s RGB amp inside by TG16. Connected to my 21" PVM all I have to say is WOW!

It's just as clean and pixel perfect as the NESRGB. I decided to use a Sega Genesis 2 port installed where the old RF port used to be and use a SCART RGB cable for Genesis.

My only complain is the audio volume. I run wires directly from the extension port pins (A1/C1) and it's really low. I need to crank the volume almost to full on my PVM. With my NESRGB, the volume is at 25% (mind you that the NESRGB does have a audio amp). Anyone else noticed this? Or am I due to so cap work inside this TG16?

[Artemio]

The audio level is indeed low with this mod.

[speedlolita]

Don't have that issue with my Duo R.

[leonk]

The audio level is indeed low with this mod.

There's one other thing I noticed.. it almost seems like a "shadow". In the case of Keith for example, when I'm walking in the blue sky levels jumping around, I can almost see keith faint shadow in front of the character in the blue sky. Almost like a faint ghosting of him. But it's really REALLY light ... It took me a few rounds to realize this. The sky also almost looks like it has jail bars when it scrolls, but when I stop, they're gone.

Anyone else noticed this? Or am I going insane?

[rtw]

I am doing an RGB mod on my IFU-30A.

Before I assemble it again, is there a game where I can test stereo channels explicitly ?

[kamiboy]

The audio level is indeed low with this mod.

There's one other thing I noticed.. it almost seems like a "shadow". In the case of Keith for example, when I'm walking in the blue sky levels jumping around, I can almost see keith faint shadow in front of the character in the blue sky. Almost like a faint ghosting of him. But it's really REALLY light ... It took me a few rounds to realize this. The sky also almost looks like it has jail bars when it scrolls, but when I stop, they're gone.

Anyone else noticed this? Or am I going insane?

That sounds like crosstalk, in which case you need better cables for transporting the video to your display of choice.

[Bancho]

I used one of brokens RGB Amps to mod my Tennokoe bank for use on my Core Grafx. I can't notice any Jailbars and the picture is great.

[rtw]

I recently did an RGB mod to my IFU-30A using otaku's NEC RGB amplifier.

Overview. Only need to remove the three screws at the back



Cabling and placement. GND and 5V is taken from the 7805, audio taken from rightmost connector



Before closing



Side view



The output is fed into an XRGB-mini Framemeister.

To test everything I used Artemio Urbina's brilliant 240p test suite: http://junkerhq.net/xrgb/index.php/240p_test_suite.

This suite also has a sound test which will verify the left and right audio channel.

Now, please tell me what is the best way to check for banding ?

[Artemio]

I didn't include a test in the suite for banding, since I am not 100% sure on how to check for it across all mods and systems. I do have a white PCE with IFU-30, and the mod inside the PCE, a Turbo Grafx-16 and a PCE Duo. The TG-16 doesn't show banding for me. The other two do at varying degrees, all of them use the THS7414 amp right now.

I did make a small rom before making the suite that has the patterns that show banding in my setup: https://dl.dropboxusercontent.com/u/1403041/banding.pce

I didn't include these on the suite since I have no idea if these are consistent or the best way to test for it. For teh record, I use a PVM and they show there, I'd need to check on the Framemeister.

I have a low bandwidth scope, If I can help just let me know what to do from either software or measuring, my background is software so I am clueless as of what to look for in terms of noise.

[rtw]

I didn't include a test in the suite for banding, since I am not 100% sure on how to check for it across all mods and systems. I do have a white PCE with IFU-30, and the mod inside the PCE, a Turbo Grafx-16 and a PCE Duo. The TG-16 doesn't show banding for me. The other two do at varying degrees, all of them use the THS7414 amp right now.

I did make a small rom before making the suite that has the patterns that show banding in my setup: https://dl.dropboxusercontent.com/u/1403041/banding.pce

I didn't include these on the suite since I have no idea if these are consistent or the best way to test for it. For teh record, I use a PVM and they show there, I'd need to check on the Framemeister.

Thank you Artemio, I tested the banding.pce and I cannot see anything on my Framemeister.

I re-read this entire thread, are you saying that the IFU-30/IFU-30A amplifies the video signal from the EXT connector ?

[Artemio]

Thank you Artemio, I tested the banding.pce and I cannot see anything on my Framemeister.

Just connected my PCE+IFU-30 system to the framemeister, and it is indeed not visible in my setup. I also tested by PCE Duo, and the signal jumps a lot. I cannot verify if the banding is visible due to synch issues with my Duo and XRGB Mini. I can build a sync stripper if needed. I also tested both units again in my PVM, and the PCE+IFU is almost unnoticeable when compared to the Duo. This at least with my test cases.

I re-read this entire thread, are you saying that the IFU-30/IFU-30A amplifies the video signal from the EXT connector ?

What I found out is the following. When I modded my white PCE system I initially took the RGB lines from the EXT port, and it worked fine. However when I plugged it into the IFU-30, everything got way brighter. I unplugged it and tested again, and it had lower levels again. So I went ahead and tapped the RGB lines directly from the Hu6260, tested it with and without the IFU-30 and levels didn't vary.

Please let me know if there is something I can measure with the scope, I only have a 40 Mhz one.

[rtw]

What I found out is the following. When I modded my white PCE system I initially took the RGB lines from the EXT port, and it worked fine. However when I plugged it into the IFU-30, everything got way brighter. I unplugged it and tested again, and it had lower levels again. So I went ahead and tapped the RGB lines directly from the Hu6260, tested it with and without the IFU-30 and levels didn't vary.

Do you mean that you took the signal from the EXT port on the IFU-30 (same as I did) ?

Please let me know if there is something I can measure with the scope, I only have a 40 Mhz one.

To be honest I do not know what to look for so I can only suggest to look for differences. Use the first image in banding.pce as the visible test.

Make a small breakout SCART (male/female) cable where you can tap the RGB and Sync signal consistently.

Find two units, one which exhibits the problem and one without and start looking at the signals.

The problem is that you need accurate probes for these measurements.

[Fudoh]

I tested the banding.pce and I cannot see anything on my Framemeister.

what kind of PCE are you using ? A classic white one ?

I have two interface units (2nd revision), one with a white PCE, one with a Core Grafx II. The combo with the PCE gives me banding on the Framemeister, the CGII combo doesn't (or hardly). The two interface units have the same RGB mod and of course I exchanged the PCE systems as well...


@Bancho: I would never expect banding from a standalone CG or CGII.

[Artemio]

Do you mean that you took the signal from the EXT port on the IFU-30 (same as I did) ?

No, sorry. I took the signal from the EXT port inside the pc engine. I wanted the mod to be stand alone. When using the white pce unit alone vs with the IFU 30, there was a huge visual difference in video levels.

I'll compare the signals and post my results here. I only have the Tektroniks 1/10x probes that came with my TBS1042 scope.

[rtw]

what kind of PCE are you using ? A classic white one ?

Classic white one. My IFU is a IFU-30A. What game/program are you using to show the banding ?

Do you mean that you took the signal from the EXT port on the IFU-30 (same as I did) ?

No, sorry. I took the signal from the EXT port inside the pc engine. I wanted the mod to be stand alone. When using the white pce unit alone vs with the IFU 30, there was a huge visual difference in video levels.

Strange, according to the TG-16 schematics, the RGB & Sync signals go directly from the Hu6260 to the EXT connector. So the only difference would be a shorter signal path by a few centimeters...

I'll compare the signals and post my results here. I only have the Tektroniks 1/10x probes that came with my TBS1042 scope.

Brilliant, please put the probes at 10x to increase bandwidth.