New 3DO RGB Mod Possibility.

[callidus]

LOVE the progress you guys have made here! Well done! I'm beyond stoked to see this inch closer and closer to becoming a reality. I'd love to replace my Otaku board with a better solution and will definitely be in for one of these once you guys are finished up.

[the_crayon_king]

Thank you for your comments. I realised I had placed C5 and C6 were too close to the IC, if I keep them in the final design, I will move them to a better position. They are extra power decoupling caps so they may not be needed. If I do move the filter caps and resistors back to the pcb, I will use your design as it's the best layout. That's interesting using the MD-80SV. I was going to use a C shape 8 pin din panel mount as these are the easiest to acquire. The only issue was finding good quality SCART cables with a 8 pin din connector for a good price.

 

I plan to release my design as open source for people to use as an alternative to the old DAC ladder design. I would of course give credit to your design as it has been very informative and helpful in my own research. I originally reviewed 6 different 8bit triple dacs and found the ADV7125 and BU3616K to be the best choices, with the ADV7125 being more high end. I have potentially deciphered the other 3DO encoders so your design should be fine to work across all 3DO https://assemblergames.com/threads/240p-output-on-3do-with-bt9103-encoder.66295/

 

I look forward to seeing how well your design works. :-)

 

Yea who knows how well these will work. I suspect anything is an improvement over the "nothing" which is the status quo.

 

Everything is on the same side I may do away with a few more caps.

 

So https://www.digikey.com/products/en?keywords=md-80%20sv

Is what im talking about. Its mountable with super glue. Basically similar if not exactly the same as whats used in Tim Worthington's kits.

The cables already exist for the NES RGB mods by retro_console_accessories.

 

If I were going to use something else it would be this: https://www.digikey.com/product-detail/en/cui-inc/MD-80CV/CP-2880-ND/352864

 

or if full sized DIN: https://www.digikey.com/product-detail/en/cui-inc/SD-80SN/CP-1280-ND/97027

The last one doesnt need a breakout.

 

I think if I have any issues it will be between RSET and VREF. I didn't do any math on it....yet.

 

Another question would be where to get 5v. Rather not pull it from the 7805.

 

This has one more slight revision before being "complete" Ill put a few together for people to test but I don't plan to make more than 3 to test with. (one for me of course)

Ill be sure to send you one. Ill order a batch of 10 blank PCBs before the week is out. So if anyone feels up to soldering these SMD components let me know.

Will probably be here at the end of October.

 

If all goes well I may look into assembly cause I sure as sh*t don't want to put a ton of these together.

Edited September 26, 2017 by the_crayon_king

[Taijigamer]

LOVE the progress you guys have made here! Well done! I'm beyond stoked to see this inch closer and closer to becoming a reality. I'd love to replace my Otaku board with a better solution and will definitely be in for one of these once you guys are finished up.

Full credit goes to @The_Crayon_King for this one. I've just chimed in with a few observations.

 

Quick work on the design change, very nice. These will definitely work, it's just a matter of testing now. With all the research so far, these should work across all 3DO and also some Philips CDi models. The good thing about the ADV7125 is it's high end so it will give stable standardised RGB outputs. Just stick to the recommended Vset and Rset values. With the BU3616K, there is not a lot of info in the data sheet and Rset was valued too high which was evident in the reports by other modders who found the picture very dark. I've had to work out Rset from what little information was given.

 

Regarding 5V, I recommend getting it from an analogue 5V source close to or from the VA536. The 7805 is a digital source and will be 'dirtier' than the very clean analogue 5V that the VA536 will use.

 

If you want someone to test your design on the BT9103 encoder then let me know, I would be more then happy.

[the_crayon_king]

Full credit goes to @The_Crayon_King for this one. I've just chimed in with a few observations.

 

Quick work on the design change, very nice. These will definitely work, it's just a matter of testing now. With all the research so far, these should work across all 3DO and also some Philips CDi models. The good thing about the ADV7125 is it's high end so it will give stable standardised RGB outputs. Just stick to the recommended Vset and Rset values. With the BU3616K, there is not a lot of info in the data sheet and Rset was valued too high which was evident in the reports by other modders who found the picture very dark. I've had to work out Rset from what little information was given.

 

Regarding 5V, I recommend getting it from an analogue 5V source close to or from the VA536. The 7805 is a digital source and will be 'dirtier' than the very clean analogue 5V that the VA536 will use.

 

If you want someone to test your design on the BT9103 encoder then let me know, I would be more then happy.

 

I deff need some testers, I ordered a batch but I realized in scraping together parts off of the BOM that I got the wrong package size for the AD1580 diode. It needs to be a 3 leg SOT-23-3, not a 2 leg SOD123. The freaking third leg isnt even used so idk. I will have to jerry rig that part of the board.

 

I will fix the PCB design in that regard on the next batch. I will get more of an idea of what needs changed around when I put these together.

[Boojakascha]

 

I deff need some testers, I ordered a batch but I realized in scraping together parts off of the BOM that I got the wrong package size for the AD1580 diode.

 

I would be in as tester. I can put the stuff onto the PCB myself I guess, I have decent tools. I have to buy a 3DO though. Is your PCB compatible with all models? I can strap a thin wire to the diode, I don't think it will be a problem.

[Taijigamer]

I've been there myself. I managed to get the rows mixed up on a xbox360 DVD power adapter I designed for flashing Xbox DVD drives. Had to reverse the wires on the power cable to compensate.

 

If the SMD lands on your pcb are suitable for 2 of the SOT-23 diode leads then u should be able to get away with it for this batch of test boards as the 3rd pin is NC like you said. It's all part of the R&D journey

 

This design will work with all 3DO as it takes 24bit RGB from the board and strips SYNC from Luma. It bypasses the native encoder. The pinout for the other encoders can be found in this thread

https://assemblergames.com/threads/240p-output-on-3do-with-bt9103-encoder.66295/

[haightc]

I have two FZ-1 (one Japanese, one US), I would be interest in prototype board

[Boojakascha]

Just bought a Japanese FZ-1. So now I am ready.

[the_crayon_king]

Just an update I have the parts but not the kits but by this weekend everything should be together. So I will start sending these out on/after the 16th.

 

I only have parts for 5 and I only want to put one or two together,. So if you are privy to try I can send out the PCB and parts.

The ADV7125 looks like is has spacing somewhere around TSSOP so if you are comfortable with that you are good to go. Ill solder all the diodes on regardless so there is no confusion on those.

 

Parts are already paid for and Ill cover shipping to US. I sell stuff to cover R&D so its not a big deal.

 

Just PM me around that time with your address.

 

Obviously post the results regardless, and post for support,. Not an easy mod but shouldn't be the hardest either.

 

As indicated in previous parts of this page no idea if any of this will work but here is hoping. Ill post an update and highlight all the needed pins.

[the_crayon_king]

I cannot find a LM1881, I have no idea where I stuck them,. board needs cleaned off. Had to use solder paste on the ADV7125 first time using it many bungged up mistakes were made. If I can find a LM1881 should have this thing tested soon after.

 

 

Edited October 11, 2017 by the_crayon_king

[the_crayon_king]

So yea it worked no prob. Well alot of probs but I got it. Lots o design changes coming.

One of the pins "power save" needs to be either left floating or tied to pos voltage using a resistor.

 

DO NOT TIE IT TO GROUND AS IT WAS ON TEH PCB DESIGN WILL NOT WORK.

I ripped the diode off didn't seem to matter although I am sure it does.

 

Ill update anything else I can think of.

 

https://www.youtube.com/edit?o=U&video_id=aFhgck1vGPc

[Boojakascha]

So yea it worked no prob. Well alot of probs but I got it. Lots o design changes coming.

One of the pins "power save" needs to be either left floating or tied to pos voltage using a resistor.

 

DO NOT TIE IT TO GROUND AS IT WAS ON TEH PCB DESIGN WILL NOT WORK.

I ripped the diode off didn't seem to matter although I am sure it does.

 

Ill update anything else I can think of.

 

https://www.youtube.com/edit?o=U&video_id=aFhgck1vGPc

 

So you want us to wait for trying, or shall we cut a trace and wire a quick fix?

 

I am afraid your YouTube link points to anybodys "myVideos" and not to your specifically.

[the_crayon_king]

 

So you want us to wait for trying, or shall we cut a trace and wire a quick fix?

 

I am afraid your YouTube link points to anybodys "myVideos" and not to your specifically.

 

Probably should wait for the next board revision. Cutting a tiny pin like that is pretty sketchy, suppose you could also try cutting the trace/pad with a razor blade.

 

Recorded in 480 but I think 240 is supposedly better ?

Images moving too fast for me to really focus on the quality.

 

The screen is centered on the xrgb. Does anybody recall if that was the case with the Otaku version or not ?

 

I will say the screen looks a bit clearer than what is shown.

This is also with vref completely missing (not a good idea) and 4 red pins bridged.

Edited October 11, 2017 by the_crayon_king

[Boojakascha]

The 480, 240 thing is just the old interlaced versus progressive story. As long as your capture card behaves correct it won't be to much of a problem in order to compare qualities. Does the console still output s-video after the mod?

[the_crayon_king]

The 480, 240 thing is just the old interlaced versus progressive story. As long as your capture card behaves correct it won't be to much of a problem in order to compare qualities. Does the console still output s-video after the mod?

 

I was using the luma pin for sync so I am not certain. I dunno if there is any loss in double terminating then to the LM1881 or just letting it run straight in. If the back porch doesn't work as blanking then that circuit may be replaced with something to just combine H and V sync. I don't know if blanking is even relevant on most peoples setups as it most certainly isn't on mine.

 

I also think that the ADV line of chips have something for taking 24bit RGB to HDMI. I know I mentioned it before someplace but can't recall where. I think the ADV8003 is what I am talking about.

 

This Friday I will be doing more tests to see what will happen if I cut the CLK [out of curiosity] (the clock pin I used was pin 60 on the VPA chip and far as I can tell correct) or change to one of the other clocks also trying to output multiple video signals RGB S-Video or RGB A/V.

 

It should be noted that I have the anode and cathode or the diode backwards on the picture (I think) like I said more testing needed.

[the_crayon_king]

Ah so quick update.,

 

Clock is absolutely necessary. I didn't test the other ones but without it you get no video. Also line is possibly susceptible to noise just something to be aware of.

 

Using the luma pin for sync stripping makes no difference in S-Video output (that I can tell).

 

Would be wise to have a resistor in line to drop to C sync voltages these will be using 8pin mini din cables so I gotta find out what are in those already. Most likely have a toggle between 470 ohm resistor (C sync out) and nothing (TTL Sync) toggle would simply bypass that resistor.

 

28 awg stranded wire is highly recommended. I was using 30 awg solid core which is also an option but I broke many lines in testing will have to reattach later (very non flexible).

 

Needed pins are highlighted here: https://i.imgur.com/P1hXK1C.png

There will need to be other directions for the other 3DO revisions but this kit should work across the board,

 

The video shows a darker RGB image but that is just because my XRGB has been messed with and I don't know how to get it back to default. I messed with gamma and brightness.

 

Now that I broke a bunch of video lines off graphics are glitchy looking over RGB I can see the issue but I'd rather fix it later when I have the next kits.

 

I could make the resistors and capacitors 0402 instead of 0805 but anybody who has ever worked with 0402 already knows why I didn't do that.

 

I still get video out when using blanking off of the lm1881 so that's good. I don't know if back porch qualifies as blanking but on most setups this shouldn't be a factor.

 

For anyone who can't wait for another revision the one marked ADV7125 FINAL already confirmed working:

https://easyeda.com/hotdog6394/3DO_RGB_ADV7125-1bfad1c801294c59bd414b17b93c6a99

Edited October 17, 2017 by the_crayon_king

[Taijigamer]

Nice work. Looking forward to seeing your final design.

 

I completely forgot about TTL sync voltages. Definitely need to add a 330-470 Ohm resistor in series to the csync line output. If not then the 3.3v decoder in the video display will get eventually damaged from the 5V sync. The only reason to have a switch to keep TTL levels would be for VGA displays. Did u manage to test RGBHV on a vga display?

 

I know what u mean about 0402 packages. Ugh! Never again. I stick with 0603 for chip resistors and chip caps. I use 1206 for led and 1206/1411 for tantalum caps.

 

I will try to put together a tutorial for installing RGB on the BT9101 and BT9103 encoders when I've finished testing.

 

Looks like blanking isn't required for newer TVs. May still be required for older CRTs.

[Boojakascha]

About blanking: The Analogue NT mini has none too. What I do to inject blanking manually is having a battery trail at a SCART socket, or (BETTER) having a G-SCART router. Possibly Hydra is also feasible.

[the_crayon_king]

Nice work. Looking forward to seeing your final design.

 

I completely forgot about TTL sync voltages. Definitely need to add a 330-470 Ohm resistor in series to the csync line output. If not then the 3.3v decoder in the video display will get eventually damaged from the 5V sync. The only reason to have a switch to keep TTL levels would be for VGA displays. Did u manage to test RGBHV on a vga display?

 

I know what u mean about 0402 packages. Ugh! Never again. I stick with 0603 for chip resistors and chip caps. I use 1206 for led and 1206/1411 for tantalum caps.

 

I will try to put together a tutorial for installing RGB on the BT9101 and BT9103 encoders when I've finished testing.

 

Looks like blanking isn't required for newer TVs. May still be required for older CRTs.

I don't have any way to test VGA.

 

Biggest concern right now is where to get a 5v signal for powering this:

 

You could possibly port this into that other encoder to make a similar kit using that DAC.

 

So the spacing of the VPA536 is 1.27mm between pins. So Im going to try to make the kit float on top of the VPA. Of course this will still work the same on other 3DOs but with the VPA based ones it will make installation way easier.

 

That design is about 50% smaller.

 

I also noticed that the datasheet calls for double 75 ohm terminations but doesn't say anything about series so I removed them. I haven't seen any ADV7125 based anything using series 75 ohm resistors.

 

Those letters on the side where RGB should be are random placeholders,. for this design to work you have to switch Green and Blue inputs it shouldn't change anything besides what outputs what color as there is no sync on green going on here or sync being applied to any of these signals in general.

 

The two pads marked Y are to set 240p should be wired to a toggle switch.

 

I am forgoing the 220uf caps they can just be put into the cable, There will be zero room to add them on the board at this rate.

 

JP1 locks blanking (No blanking)

JP2 uses the back porch for blanking (no idea if that qualifies)

 

JP3 bypasses the output resistor for C sync to make TTL sync. This would be for VGA or people who already have resistors in their scart cables.

Edited October 20, 2017 by the_crayon_king

[the_crayon_king]

About blanking: The Analogue NT mini has none too. What I do to inject blanking manually is having a battery trail at a SCART socket, or (BETTER) having a G-SCART router. Possibly Hydra is also feasible.

Never heard of a battery trail what does something like that entail ?

[Boojakascha]

Never heard of a battery trail what does something like that entail ?

What I tried is connecting two Mignon cells to pin 16 (plus) and 18 (minus) over a resistor, with a battery caddy hanging down from the SCART socket. I think I had limited success. However eventually I owned a G-SCART and stopped using this kludge.

[Taijigamer]

Good idea. I was starting to lean towards quick solder options with my design as well. Either with pin headers or QSBs. A different design would be needed for each encoder but it would make installation a lot easier. This is not possible with the BT9101 encoder as it is a fine pitch 160 pin QFP.

 

I made a mistake with my design by including a parrellel termination resistor AND a series termination resistor. Only one is needed, my design was effectively triple terminating the signals, oops. Analogue Devices use parrelel terminating resistors in their designs while the online community advocate series resistors.

 

It is advisable to place the 470ohm resistor close to the console end as possible but as you said, the AC coupling caps (220u - 1000u) can go either end on the line.

 

This page has some good info on reducing parasitic capacitance in video signal lines https://shmups.system11.org/viewtopic.php?f=6&t=55948

[the_crayon_king]

Good idea. I was starting to lean towards quick solder options with my design as well. Either with pin headers or QSBs. A different design would be needed for each encoder but it would make installation a lot easier. This is not possible with the BT9101 encoder as it is a fine pitch 160 pin QFP.

 

I made a mistake with my design by including a parallel termination resistor AND a series termination resistor. Only one is needed, my design was effectively triple terminating the signals, oops. Analogue Devices use parallel terminating resistors in their designs while the online community advocate series resistors.

 

It is advisable to place the 470ohm resistor close to the console end as possible but as you said, the AC coupling caps (220u - 1000u) can go either end on the line.

 

This page has some good info on reducing parasitic capacitance in video signal lines https://shmups.system11.org/viewtopic.php?f=6&t=55948

 

Viletim knows all. I've seen that page many times in my research.

 

All the extended datasheet says is something like "the ADV DACs are designed to either have a single or doubly terminated 75 ohm load (double being preferred)"

 

The datasheet doesn't mention series at all. There must be a reason.

 

Notes:

The equation for IOG is the same as that for IOR and IOB when SYNC is not being used, that is, SYNC tied permanently low.

Means I should be able to switch Blue and Green as long as I don't have sync.

 

I have to reapply VREF to get accurate measurements right now I am hitting a little over 2V (unterminated) but still it should be around 1.4v

 

VPA536 is a 68 pin PLCC I think it is 25x25mm but IDK. I already made the header off of a PCB lib of another 25x25 68 pin PLCC we will have to see how that lines up.

 

Progress so far:

 

 

 

Although it looks very similar to the last one there have been many changes. Probably one more set of edits before its ready to order.

 

Let me test against the VPA536 then we will know whether the pins will line up for either version of this.

 

If I remember correctly the N64 HDMI mod has one of those quick solder things and it is similarly spaced 120 pins.

I wonder if there is a way to interface it so that all revisions can use the same kit without much fuss.

 

Id have a square mask that broke out those connections to solder-able pads meant for ribbon cable.

ribbon cable into 1.27 spaced holes seems clean enough then you can use the same base kit for everything only changing that mask (i dont even know what those are called.

Edited October 22, 2017 by the_crayon_king

[Taijigamer]

Here's some info on termination types https://www.diodes.com/assets/App-Note-Files/AB023.pdf

 

And from your favourite company http://www.ti.com/lit/an/snla034b/snla034b.pdf

 

Each method has its advantages and disadvantages. Older consoles such as Sega MD, Ps2 and possibly 3DO use series termination, while Sega DC uses parallel termination.

 

Yes I was thinking a specific 'U' or 'L' shaped QSB with a 28 pin ffc connector for each encoder, connected to a generic main board. 24 bit RGB, CLK, SYNC, 5V and GND could be acquired directly from the native encoder, or power separately, and fed to the main ADV7125 board via ribbon cable.

 

Good luck with your new revision.

[Arithmaldor]

Would it be possible to integrate a 68 position PLCC socket into the design?

Like this one:https://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/8468-21B1-RK-TR/?qs=sGAEpiMZZMs6akeJfFiy2rc%2ftN2YUFFe

This would make the mod infinitely easier, just snap on and solder wires to the output connector. The NeoBIOSMasta (https://www.neogeofanclub.com/projects/neobiosmasta-og) uses this technique.

 

Edit: Though this may not be possible due to components too close to the IC.

Edited October 26, 2017 by Arithmaldor