What's the deal with the Turbo/PCE video signal?

[Black Tiger]

Before I bought my LCD TV, I asked the experts over on the HDTV Arcade forums a few questions as I was researching HDTVs.

Several people told me that HDTVs were no good for playing classic consoles on, because (among other things)most can't upscale the 240p signal fast enough and the framerate chugs.

So when I tried my Duo on my new LCD and it was all choppy, I thought "oh well, no big deal", since it was primarily for my Xbox 360.

But tonight I hooked up my NEX to test out an NES cart I picked up and it worked fine. So I tested my Duo again with the modded composite out and the regular Duo A/V cable. But it's the same as with the S-Video, the game runs at like 15 fps.

I just tried my Multi Mega and it also works fine. The signal from all three console's signals is just called "NTSC" by my TV, where 720 x ' signals have a more detailed description(R-Type 1 on R-Types PSX runs in 720 x 240 for example).

Anyone have any idea why only the PC Engine doesn't work on my TV?

[Tatsujin]

Anyone have any idea why only the PC Engine doesn't work on my TV?

very strange phenomenon indeed!
may be, because the resolution of the PCE is slightly different to the NES or MD, the HDTV can't handle well just this specific kind of resolution?!

[Joe Redifer]

Try hooking up a Genesis and running Sonic 2's 2-player mode and see what happens.  Then run a low resolution Genesis game like Air Buster or Arrow Flash or Lords of Thunder (which run in the same 256x224 resolution that Turbo games do).  Anything peculiar?

[Black Tiger]

Try hooking up a Genesis and running Sonic 2's 2-player mode and see what happens.  Then run a low resolution Genesis game like Air Buster or Arrow Flash or Lords of Thunder (which run in the same 256x224 resolution that Turbo games do).  Anything peculiar?

Sonic 2's regular and splitscreen modes both work fine and so did Mega Bomberman.

But Forgotten Worlds and all the 'low' res Turbo games I tried are all choppy. 

EDIT: I just tried a SNES2 and it ran Ys III fine, but there were some rainbow effects on a couple dithered spots.

So I guess I just happened to pick out a TV that specifically hates the PC Engine. 

Is there anything special about the PCE's signal that could cause something like this? Even the S-Video mod off of the RGB mod produces the same results.

Anyone else have a 720+p digital TV you can test a Turbo/PCE on?

[Digi.k]

I'm actually waiting on a new lcd tv to arrive mid week so I get back to you on this..

Your problem isn't new a lot of people have experience with this..some hdtv's should have a game mode.

I got this article from another forum:

Why do HDTVs lag on video games?
HDTVs typically only have one or two "native" resolutions. A set's native resolution is the resolution that it displays on the screen. This means that sometimes, the HDTV must "scale" the resolution you input in order to display it.

On regular, non-HD televisions, there is only one native resolution, which is 480i (240p). Whenever you play a video game on a standard definition TV, the game console always outputs 480i/240p and the TV displays it as 480i/240p. No need for any scaling, so response time is always normal and accurate.

However, because HDTVs NEVER have 480i/240p (Standard Definition) and usually not even 480p (Enhanced Definition) as a native resolution, that means that any video game console we have that can't output a High Definition signal is likely to lag on any HDTV display. It isn't that it is impossible to scale an image with no lag; HDTVs simply put the emphasis on image quality, which takes some time to process, rather than speed. Some newer HDTVs now come equipped with a "Game Mode" to speed up the scaling process and reduce or eliminate lag on the set.

You can read more of that here:
http://www.avsforum.com/avs-vb/printthread.php?t=558125&pp=60



I think for getting decent images of retro machines on lcd hdtv's you need to get some sort of converter that upscans the image from old retro machines so they look nice on hdtv's.  Some sort of external device that does XRGB

You might need to investigate into this as I won't know for sure what is needed till my hdtv arrives and I can see if there's any damage myself.

[Black Tiger]

I'm actually waiting on a new lcd tv to arrive mid week so I get back to you on this..

Your problem isn't new a lot of people have experience with this..some hdtv's should have a game mode.

I got this article from another forum:

Why do HDTVs lag on video games?
HDTVs typically only have one or two "native" resolutions. A set's native resolution is the resolution that it displays on the screen. This means that sometimes, the HDTV must "scale" the resolution you input in order to display it.

On regular, non-HD televisions, there is only one native resolution, which is 480i (240p). Whenever you play a video game on a standard definition TV, the game console always outputs 480i/240p and the TV displays it as 480i/240p. No need for any scaling, so response time is always normal and accurate.

However, because HDTVs NEVER have 480i/240p (Standard Definition) and usually not even 480p (Enhanced Definition) as a native resolution, that means that any video game console we have that can't output a High Definition signal is likely to lag on any HDTV display. It isn't that it is impossible to scale an image with no lag; HDTVs simply put the emphasis on image quality, which takes some time to process, rather than speed. Some newer HDTVs now come equipped with a "Game Mode" to speed up the scaling process and reduce or eliminate lag on the set.

I think for getting decent images of retro machines on lcd hdtv's you need to get some sort of converter that upscans the image from old retro machines so they look nice on hdtv's.  Some sort of external device that does XRGB

You might need to investigate into this as I won't know for sure what is needed till my hdtv arrives and I can see if there's any damage myself.

Thats what I figured at first, when all I had tested was my Duo. But so far all old 240p consoles display fine except for my PC Engines.

I just tried my Shuttle on it, in case my Duo was somehow changed by the video mods, but it's the exact same. 

[Joe Redifer]

And the NES works fine, right?  To my eye the NES and the Turbo/PCE have similar composite.  Maybe there is something about the Turbo signal that is ever-so-slightly out of sync with what it should be and that messes up HDTVs, but not SDTVs.  If I am not too lazy later I will try my Turbo on my CRT HDTV... though I think I *may* have done so a long time ago.

[Keranu]

I can't really tell a difference between NES and TG16 composite either.

[nat]

Not sure if this is related, but recently I hooked up a spare Turbo to an old PowerMac 6300 I have with a video-in & capture card. It will take RF, composite, and S-Video video input. My idea was to have an extra console hooked up in another room seperate from the flatscreen so I would have a place to go hideout if the woman had company over and I felt like being anti-social. Hey the computer has a fairly large monitor and is right in front of a lazyboy, so why not, right?

I made my own adapter to pull a composite signal directly off the expansion bus on the back of the TG-16 since I refuse to go RF. I've done this many times over the years, so I know what I'm doing here.

However, I have the EXACT SAME problem. The video shows up on-screen at around 15 FPS. The video is not decoded or otherwise handled by any kind of software, it's a strictly hardware setup so I am at a loss as to why this is happening. The RF signal coming in from my cable TV coax runs perfectly smootly as do any other video devices I attach to both the composite or RF (video camera, VCR, DVD, etc). I haven't tried another console yet, though.

But I wonder if there isn't something funky about the Turbo's video output after hearing  this experience...

[ccovell]

This is a new one.

Try Space Harrier, Bonk's Adventure, OutRun, Volfied, or Rastan Saga II with your LCD TV.  Do those run at full framerate?  I have a theory...

[Joe Redifer]

I hooked up my Turbo to my HDTV (Sony 34XBR960) and it did not stutter.  Smooth as silk.  Unfortunately it looked like ass:



Ew.

[Black Tiger]

This is a new one.

Try Space Harrier, Bonk's Adventure, OutRun, Volfied, or Rastan Saga II with your LCD TV.  Do those run at full framerate?  I have a theory...

I've already tried Bonk's Adventure and it was also choppy. Should I still try OutRun or Rastan Saga II?

My Duo works fine on my 480p digital projector(which runs up to 1080i).

And the NES works fine, right?  To my eye the NES and the Turbo/PCE have similar composite.  Maybe there is something about the Turbo signal that is ever-so-slightly out of sync with what it should be and that messes up HDTVs, but not SDTVs.  If I am not too lazy later I will try my Turbo on my CRT HDTV... though I think I *may* have done so a long time ago.

I hadn't tried a real actual NES yet, just the Generation NEX. But I just hooked one up a few minutes ago and after a lot of work managed to get it to boot up a cart which played fine.

Incidentally, on my LCD it looked like the real NES had a slightly better overall picture by my unique tastes. I think I'll try to compare them on a regular TV later and if the difference is noticible, I might get the pins replaced on one of my NESes.


So far, it sounds like we have two confirmed HDTV's spitting out the PCE video. I'd pack a Duo over to friends houses if I knew anyone else with an HDTV.

[Necromancer]

Let me preface this post with the fact that I am by no means a genius concerning Turbo hardware, or anything else for that matter.

If I remember correctly, the Turbo doesn't output video at 60hz, but something close to it (59.?hz).  Most LCDs refresh at 60hz (some new models refresh at 120hz), so maybe some sets really don't like this little difference.  I have no idea what the NES, Genesis, etc. cycle video at.  Maybe they all output video at some weird rate too, which would blow my theory clean out of the water.

[Joe Redifer]

It's 59.94 Hz.  Why not 60hz?  Well it used to be 60Hz... until they added color.  So all proper NTSC video runs at 59.94 Hz.

[nat]

This is a new one.

Try Space Harrier, Bonk's Adventure, OutRun, Volfied, or Rastan Saga II with your LCD TV.  Do those run at full framerate?  I have a theory...

Hey!!!

This may not have worked for Black_Tiger, but on the system I have problems with (computer -> video-in) the above games DO work in full frame rate! The other game I tested, Air Zonk, chugs at like 15 FPS.

What's your theory?