Transcoder, S15KHz, CRT tv screen rolling issue

[wordsworth]

New to the forum and glad to join the community!

I'm using a PC with a P4, MicroXP, Soft-15KHz, GeForce 4 MX420 PCI (w/ proper drivers and verified S15KHz compatible) through an RCA VHDC300 transcoder into a Toshiba 27D47 CRT tv with component ins.

My problem is the image displayed on the CRT is rolling like there is some type of sync issue. I'm almost positive I'm getting 480i out of the pc because after I installed S15KHz my pc monitor no longer works. I've tested the setup with my Vizio LCD tv and it's fine so I think this eliminates problems with the transcoder, cables, etc. I've also tested the CRT with a DVD player connected to the component ins and this is fine too so I don't think there is a problem with the CRT.

It seems to me to be related to the software settings. I have not installed Powerstrip yet as I'm stuck with the sync issue but I don't think I really need it yet just to verify the CRT tv is accepting the 480i.

The nVidia ForceWare driver allows me many options and I worry that one of those (h.sync polarity, v.sync polarity? front porch, back porch... foyer ) might be causing the problem although nothing I try changes the problem. All resolutions that I've tried (320x240 up to 640x480 and in between) have the exact same issue.

Any help or input would be greatly appreciated. Once I get all of the hardware setup and running I plan on building the greatest cab ever made (in my own mind of course) and I can't wait to share it with y'all!

[wordsworth]

Update on my situation. I've installed PowerStrip but this doesn't seem to offer me any help as far as my sync issue.

I've got a video of the issue so it's easier to see what's happening.




You can see the image isn't displayed at first (no signal message) because it's still in 480p but when I hit the return key you see the tv receive the signal and shows the rolling, sync issue I'm having. Towards the end of the video you can see it switch back to 480p and the image changes to a more garbled picture and then the tv shows the no signal message again.

It doesn't seem to me that this is an incompatible signal being sent to the tv as the incompatible signals are just cut off (no signal message). I don't think that there should be a problem with this tv handling this type of signal but... maybe.

I hope there is something I can do to get this resolved. I can see this might be turning into a you-just-bought-the-wrong-tv issue but I don't exactly have a lot of money laying around for another tv 

I've also included a pic of my PowerStrip settings

[wordsworth]

Well I've made improvements but nowhere near being able to even think about even installing MAME.

PowerStrip had helped me get a partially stable image but it is so touchy that you can't really make adjustments. This video shows some of what I'm dealing with. I did have it stable but it didn't take long for it to start rolling although its much better than before.



I suppose that this tv is very sensitive to refresh rates and needs something very specific although I'm still too green to figure it out. Can anybody out there give me some tips on settings for this tv?

[rCadeGaming]

The TV should be good.  Searching the model number, I was able to confirm that this is in fact a 15kHz TV, meaning it can display 480i or real 240p, so its suitable for MAME.

Here is the service manual:

http://elektrotanya.com/toshiba_27d47.pdf/download.html

If you get this working, you will want to get into the service menu to adjust geometry.  Start at p. C-1.  DO NOT initialize to factory data.  You could brick your set.

I'm trying to read your numbers in the video from your last post. 

Interlaced
H and V Sync both negative
Horizontal Scan Rate: ~15.9kHz
Vertical Scan Rate: ~30.5Hz (that actually means 61Hz per field, powerstrip displays the per-frame rate for interlaced resolutions)

Is this correct?  If so, that looks fine.  You could try getting it closer to the NTSC standard 15.750kHz and 30Hz (actually 60Hz, but Powerstrip will call it 30Hz in interlaced) and try different combinations of sync polarity (both negative is standard, but just to see if the transcoder wants something else for god knows what reason), but what you're showing should already be well within the acceptable range for a standard def TV.

I would suspect either the graphics card or the transcoder.

Did you install the nVidia drivers prior to Soft15kHz?  Even if everything's installed correctly, it's possible the graphics card may not be properly outputting the numbers shown if it's not suitable for a low scan rate, low pixel clock, or custom timing values.  I know you said it's confirmed compatible with Soft15kHz, but there can be several variations of the same card made by different companies.

I'm not familiar with that transcoder, and it may not be designed for less than 31kHz horizontal scan rate, meaning less than 480p.  Have you tested with any other monitor with Soft15kHz running, or do you mean you tested it with your LCD TV while you were still outputting higher resolutions?

Wait, wait, wait.  I just saw that you're running MicroXP.  Is Soft15kHz compatible with that?  You need to start with either standard XP or XP64 to make sure that OS isn't the problem.  I'll leave the above to be checked afterward, but the OS is really what I'd suspect first.

btw, if you want the "greatest cab ever made" you're already off to a great start in that you're planning to run native resolutions on a real CRT, but I would recommend switching to a Radeon HD4XXX-series graphics card and running CRT_Emudriver and Groovymame instead of Soft15kHz.  You can store a lot more resolutions (which you will need), get more flexibility in adjustments, and make adjustments using ArcadeOSD instead of Powerstrip.  ArcadeOSD is custom-made for this application and is much nicer when working with low resolutions.

[wordsworth]

Okay, good catch on the OS. The thought actually never occurred to me that MicroXP could cause an issue with Soft15KHz. Guess I might've outsmarted myself on that one. I'll get a copy of standard XP32/XP64 installed before I test any further.

I don't know how you could make out those settings in that video but you were right. I tried many different settings but… we'll see after I reinstall XP. (I did install the GFX drivers before S15KHz)

I had the video card laying around. I was shocked to see it matched one of the cards on the list. It's the exact same card (even PNY) so hopefully the card is okay although the whole Grovymame thing would eliminate it as a possibility.

The transcoder is the same one that notbillcosby used in his cab:

It's that RCA transcoder I PM'd you about
...it was $10.01 after shipping

The Audio Authority 9A60 or the RCA VHDC300.  Either one sounded like it would work, just a little iffy.  Certainly worth the risk at that price.

After I installed S15KHz and restarted I lost my computer monitor (incompatible signal) so I assumed that I was in 480i at that point. I connected to the CRT tv and got the terrible rolling (1st video) and then the only way I could see or change anything was with my LCD tv.

I know notbillcosby had some trouble with his setup but it seemed more related to the video card that his transcoder. I REALLY hope this transcoder is okay because although I'd love to have a Crescendo I couldn't (legally) acquire one at this time.

I've been reading some on CRT_Emudriver and Groovymame. I'd like to get my current setup going if possible but knowing myself I'll eventually switch over so I can be like all of the smart people.

Now after all of that typing… well, in my mind there's no point in messing with anything else until I have a known good OS to work with so I'll update after I have. Thank you so much for your help!

[wordsworth]

Yeah, let it be known that MicroXP and Soft15KHz do not play well together... well at least the version I used but who knows how many versions are floating around out there. Anywho... not my brightest moment.

Tonight I wiped everything and installed plain jane XP32, video drivers, S15KHz, PowerStrip and still had video on my computer monitor. When I added 640x480i (~15.75 and ~30), switched to the CRT TV and clicked okay I got the same rolling/flickering. Then I changed the -syncs to +syncs and there you go, a stable picture. Not the best looking thing by far but much, much better than before.

I've got my work cut out for me with the picture quality and the tv's geometry being all out of whack so I'll be grinding that out for a few.

One question for you Rob. There's a horrible tear near the top of the screen where you can see the image looks like its been ripped. It's clearly not lined up with the rest of the display. If I crank up the horizontal refresh I can almost get it to line up but not quite before the image becomes unstable. Any ideas? I can get a picture up tomorrow to show you. Thanks again for your help!

[rCadeGaming]

When it's time to start scanning another frame, the vertical sync pulse tells the deflection beam to whip the electron beam back to the top of the screen.  This jump makes the electron beam very unstable and it needs a little time to stabilize.  This usually takes place while it scans a few blank lines above the active picture in the vertical back porch. 

First try increasing vertical back porch to give it more time to stabilize.  There also might be some setting in the service menu that can help stabilization in this area.  There are several on my Trinitron.  Finally, running the vertical sync pulse through a potentiometer to adjust signal levels may have an effect on this.

I'll paste in something pertinent I just wrote in another thread

the biggest general tip I can give is that you need to have a rock solid understanding of how the CRT actually works and what you're really adjusting.  I mean how it is physically scanning the lines onto the screen, what the h and v sync pulses do, horizontal and vertical scan rates, and how all of these are controlled by active pixels/lines, front porch, and back porch  values.  Then on the computer side, learn exactly what EVERY number in a modeline represents, and what the graphics card's pixel clock is/does.  Get on the Googles.

[wordsworth]

Thanks for the advice. I have been studying up on old CRT tech and I do find it quite interesting. Another hobby of mine is fixing/building vintage guitar amps so tubes and old tech are right up my alley. I'll grasp it eventually.

Here's the tear near the top of the screen. I've adjusted the vertical back porch to the point that the image becomes unstable but it's still there. I'm really worried that there is just something in my signal chain that is just not going to work.

This one shows the settings a little better, nothing new really.

This one really scares me. You can actually see the different frames during the interlacing process. Pretty cool to look at but daunting to eliminate. (btw this isn't an artifact of the camera/tv interaction, it really looks like this in person)

Just to check that the tv is not totally whacked out I connected my... *clears throat* ... Wii to the component ins in 480i and it looks very normal. This tells me that the issue is related to the video card or transcoder or the interaction of both and/or the tv.

Give it to me straight. Is this setup hopeless? It sure looks bad to me. I'm still learning but some of those issues don't seem like they can be adjusted away.

I'm going to be learning all I can about CRTs. I really appreciate the help you've given me not only here but in quite a few other threads. You probably single-handedly influenced me into going for authentic resolutions and refresh rates by using a CRT tv. I'll keep grinding away at it.

[rCadeGaming]

That looks like something else than what I'm talking about.  You can see that it's already stabilized by the time visible picture begins at the very top, before the problem begins.

I don't know.  Now that OS is ruled out, I'd say again that I suspect the card and the transcoder.  It's possible that transcoder isn't designed to handle sub 31kHz signals or it's not designed to handle interlaced.  Have you tried any 15kHz progessive signals, like 240p, now that you've gone to standard XP?  It's also very odd that it needs positive sync pulses.

If you really want to get deep into working on this stuff, you could put your signals through an oscilloscope to diagnose them.  That requires a lot of know-how though.  I have a guy I go to for that kind of stuff; a retired pro. 

I wouldn't put that much work into the current setup if you might switch to CRT_Emudriver anyhow.  You could get a compatible card that's proven on eBay, and for a cheap proven transcoder you could make a VGA to SCART adapter and use a CVS-287.

This is the exact card I use, so it's gauranteed to work:

http://www.ebay.com/itm/370803033617?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

http://www.ebay.com/itm/171002389757?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Cheap but reliable transcoder:

http://www.ebay.com/itm/SEGA-SCART-to-RGB-YPbPr-YUV-Component-Video-Converter-/370695549265?pt=US_Audio_Cables_Adapters&hash=item564f2d3151

There is probably another cheap transcoder option not requiring an adapter, but the only thing I can personally confirm are this and the TC1600.

If you want to stick with Soft15kHz, I could sell you some GeForce 7300 GS's that I've confirmed to work.

[wordsworth]

The progressive resolutions aren't any better. Similar issues only with a start menu the size of my hand.

Guess this is a good excuse to move to a CRT_EmuDriver compatible, Radeon. I'm still using an AGP motherboard so I'll have to find an appropriate model. (thanks for the offer on the 7300's)

I'd love to be able to tell you I own and regularly use an oscilloscope but I'm not ready for that kind of commitment... yet.

I'll try the new card and see where that leaves me with the transcoder.

Well I suppose it's time to reevaluate my situation. Got a lot of reading to do. GroovyMame frightens me a little. I'll be back in a little while with an update for all my fans out there, you know who you are!

Seriously though rCadeGaming, you're one of the most knowledgable and intelligent members on this forum. I'm fortunate to have had some one-on-one time with you. Thank you very much!

[rCadeGaming]

I'm still using an AGP motherboard so I'll have to find an appropriate model.

My thinking is that I don't like putting money into temporary things that I'm going to have to replace anyhow.  I'd wait until you can upgrade to a motherboard w/ PCI-e.

Maybe try replacing the transcoder first and see what that gets you.  I have a CVS-287 I don't use anymore.  If you want, I can make up a VGA to SCART adapter and confirm it's working that way, and sell it cheap.

I'd love to be able to tell you I own and regularly use an oscilloscope but I'm not ready for that kind of commitment... yet.

Don't worry I don't have one either.

GroovyMame frightens me a little.

Actually you can use CRT_Emudriver without GroovyMAME.  I'm currently using it with a version of vanilla MAMEUI that I compiled myself.  I don't want to get into GroovyMAME's auto-calculated modelines because I'd rather tweak them myself for perfect size and centering.  Calamity is working on a new version that will allow you to use your own custom modelines, so I'll be switching over at that time.

Seriously though rCadeGaming, you're one of the most knowledgable and intelligent members on this forum. I'm fortunate to have had some one-on-one time with you. Thank you very much!

Not a problem.  Anyone can learn this stuff though.  I knew nothing about it a year or two ago.  There are a couple of other members here who are a lot more knowledgeable.  I'm just the one that's obsessed with native res on a TV.

[wordsworth]

My thinking is that I don't like putting money into temporary things that I'm going to have to replace anyhow.  I'd wait until you can upgrade to a motherboard w/ PCI-e.

Maybe try replacing the transcoder first and see what that gets you.  I have a CVS-287 I don't use anymore.  If you want, I can make up a VGA to SCART adapter and confirm it's working that way, and sell it cheap.

Good point. I'll PM you about the transcoder.

Actually you can use CRT_Emudriver without GroovyMAME.  I'm currently using it with a version of vanilla MAMEUI that I compiled myself.  I don't want to get into GroovyMAME's auto-calculated modelines because I'd rather tweak them myself for perfect size and centering.  Calamity is working on a new version that will allow you to use your own custom modelines, so I'll be switching over at that time.

See, I've got a lot of reading to do. 

Calamity is another smart cookie around here. I've been tempted to try Linux and GroovyMame based on his recommendation. Like I said 

[wordsworth]

A small update for anybody following this thread.

I bought a CVS-287 transcoder (SCART to VGA adapter included) from rCadeGaming and it works great. I picked up where I left off earlier and just substituted the CVS-287 for the VHDC300 in the signal chain and the picture immediately synced right up. So no other changes in the setup apart from the transcoder and the evidence is pretty clear to me, the RCA VHDC300 no es bueno!

From my research the RCA VHDC300 is meant for more modern resolutions (480p, 720p, 1080i) and I did have decent results when using it with a HD television but I think it's is a poor choice if you're trying to get resolutions close to what an arcade game requires on a 15KHz TV. Maybe it's more forgiving with a different video card or television but it's no good for me.

My next task is to tweak it up and see what I've got.

The issue looming on the horizon for me is that CRT_Emudriver is now the better option but this particular setup isn't compatible. I realize a $20 video card would resolved this but... we'll see. I have acquired another computer that might be compatible with CRT_Emudriver but I'm planning on building 2 cabinets and might just keep this one with soft15K.

By the way I've included pics (not very good ones) of both of the transcoders so those interested can identify them visually.

CVS-287



VHDC300

[wordsworth]

So some big changes here for my rig.

PC: Pentium 4, 3GHz (my other one was P4, 2.4) and a Radeon X300 PCIe video card. Same WinXP32 OS.

• The old PC couldn't use CRT Emudriver which means I would've been stuck with Soft15KHz and PowerStrip which is outdated

Transcoder: CVS-287 with SCART to VGA adapter

• For very obvious reasons if you read the last post

TV: Sony KV-24FS120

• The Toshiba is a little big for what I'm planning and the Sony is just better suited overall for this type of this anyway

I now have a new set of issues that I'm working out but my first issue is as soon as I got CRT Emudriver up and running at 15KHz through my transcoder/tv I had this:


If I choose a slightly different res I get this:


Now my question. Is it okay the glitch is there right off the bat? I know I can adjust it out with ArcadeOSD but I just wanna make sure it's okay to have this problem right from the start and that I don't have a hardware issue.

There is also about an inch of space on the left and bottom where the image doesn't line up with the tube. Obviously this can be adjusted but should my goal be to adjust this out with ArcadeOSD or with the TV's geometry? Are there any geometry pots inside the CVS-287?

Also with CRT Emudriver I can use the both the Catalyst 6.5 or Catalyst 9.3 drivers but I have no idea which (if either) is better. I see that 6.5 offers more modes but I don't know if there are any other differences. I've gone with the 9.3 'cause I figured newer is better.

[wordsworth]

I opened the CVS-287 and there are 6 adjustable pots on the circuit board although there are no markings as to what they do. I haven't had time to yet but I can try to adjust some of the pots and see what happens. I figure I'll at least be able to adjust the H position (and maybe V position?) which will be nice and if I'm lucky one of the pots will fix the weird tear in the screen (again, I understand this can be adjusted out but it would be nice to have it sync up nice right off the bat).

Here are some closeup pics of the TV displaying some native res. Pretty awesome to see real hardware scanlines for the first time





Maybe some of those adjustment pots in the CVS-287 can control the color levels. It seems the red and green maybe a little hot as far as my untrained eye can see.

[rCadeGaming]

That is the exact TV that I tested the transcoder with, so no hardware issue there.  The card you're using is also recommended as one of the best for CRT_Emudriver.  What you're seeing isn't a glitch, it just requires some adjustment.

To correct the problem in your first picture of ArcadeOSD, go into horizontal geometry and adjust the horizontal geometry until it is roughly centered.  The screen being so far to the right could be the entire problem.  If the problem persists go into edit modeline (most of your adjustments will be made from here), try adjusting the dot clock to increase horizontal scan rate a little.  Keep vertical scan at 60Hz by adjusting total lines.  Make sure "lock scan rates" or whatever it says is off.

Will you be using this TV for anything other than the PC, like a game console? 
-If so, display your other source and roughly adjust size and centering using the TV service menu. 
-If not, get 640x480i@60i roughly centered using ArcadeOSD, then sized using the TV service menu.

Next, make fine adjustments to geometry while displaying this test pattern in 640x480@60i:


Once the TV is set up, you should be mostly adjusting resolutions in ArcadeOSD to fit the TV.  You will have good control of horizontal size and centering, and vertical centering, but keep in mind that vertical size can only be controlled in the TV service menu.  You'll have to get it to a happy medium for the games you'll be playing.

The pots inside the CVS-287 are red, green, and blue upper and lower cutoff levels.

To adjust color, first set your brightness and contrast on the TV using this test pattern:


Then, use the pots in the CVS-287 to adjust individual color levels.  You should be able to identify which is which by adjusting them and looking at this test pattern:

Just set the lower cutoff levels so the transition to black at the left sides of those bars is smooth and gradual, and ends at the same place for each color.  Then adjust the upper cutoff levels by doing the following:

First, focus only on red, and set it to go a good level.  This depends on your preference.  You can make it as vibrant as you want, but you will be able to see when it becomes oversaturated as subtle differences in shade blur together and it will bleed over onto neighboring areas.  Try this both in-game, and using the above test pattern.

Then look for something that's intended to be pure yellow.  In terms of light, pure yellow is an equal mix of red and green.  So, now that red is set, adjust only green.  When there is too much green, yellow areas will have a green tint.  When there is too little, they will have a red tint.  You can use the yellow bar in this test pattern:


Finally, look for something intended to be pure white, which is equal parts red, green, and blue.  Since the other two are set, finish by adjusting only blue.  When there is too much blue, white areas will have a blue or "cool" tint.  When there is too little, they will have a yellow or "warm" tint.  Some people may prefer a cool or warm tint, but I just set it as neutral as I can.  Pure white means the colors are well balanced.  You can use the right-most white bar on the above test pattern.

You might to recheck your lower cutoffs after this.

Oh, and your card is one of the few that works with both the 6.5 and 9.3 firmware; with most you don't have a choice so I don't know a lot about the differences.  If there are no advantages to 9.3, you might want to go with 6.5 to get as many modes as possible.  Trying asking Calamity if there is any tradeoff.

[wordsworth]

A wealth of information as always. You could copy and paste your posts into a book and sell it. I think Saint should have you write a section in his next revision.

Anywho, I'll be fine tuning for the next while. I sure appreciate it!