Master System

Started by ken_cinder, August 05, 2007, 08:41:52 AM

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ken_cinder

I just picked up a Sega Master System, complete and boxed for $5 (Awesome, had to share).

Thing is, hooked up to my LCD TV this thing has some SERIOUSLY BAD overscan. I can handle a bit of overscan, but this is downright distracting.
I cannot access any service menu on my TV, as I don't know the codes (And a google search turns up nothing), so I figured that you guys might be able to offer some advice.
Is there any way to correct this overscan in the Master System itself, by way of....whatever?

kendrick

Are you using the Composite or the RGB connection? Also, does your Master System have the Sony CXA1145 or the Motorola MC1377 video encoder chip? Those two chips are supposed to be pin compatible, but I imagine that the Sony produces a sync signal that's more tolerable than the Motorola. If you can get another console or have a friend who has one, it's worth comparing if there are differences in the way that the different video output is rendered by your LCD screen. Barring that, you might want to pipe the RGB through an upscanner and use your SMS that way.

-KKC, getting his ass kicked in Phantasy Star Universe

ken_cinder

Composite connection, no RGB as I'm from Canada with an NTSC TV and we don't do RGB like you lucky suckers with SCART do lol

As for what encoder, no idea. I literally just picked this thing up hours ago, and I don't know anyone else with a Master System. If I told anyone I know that I had one, they'd probably look at me funny because they don't know what it is, or they'd think I'm crazy for still playing one.

Buying an upscanner for an SMS is highly out of the question. I was hoping on such an old system, there would be a simple way of killing the overscan.

kendrick

Normal resolution on an SMS is what, 240x220? It's possible that your LCD TV has a decoder that doesn't know how to handle that signal, and so does some funny pixel doubling which would account for the overscan. You happen to know if you can do one-for-one image rendering? That would stick a 240x220 image in the middle of your screen, but at least you would know that the LCD is handling the image correctly. There's no good way to adjust the output of the game system, only the way that the screen interprets it.

This is exactly the reason why I want to go around and snap up any tube TV sets that are left on the market. Older game consoles will be unusable without upscanners in a market where none of the screens can handle old RF or composite signals. That'll stink.

-KKC

ken_cinder

I have no real control over the TV, but it does stretch everything to 16:9 and rather nicely I might add. The SMS picture looks great on my TV, just the amount of overscan is rather huge compared to my other systems, so it's a bit distracting to see such a large amount of black space all around the image.

Guess I'll just have to deal with it until someone finds a service code for my TV. I hope someone does soon, so I can get my Gamecube to display without any overscan in progressive mode (Whoever the 'tard is at Nintendo, that didn't design it to NOT overscan in progressive, needs to be shot)

blackevilweredragon

Actually, it wouldn't be Nintendos fault..  TVs use seperate overscan settings per scan-rate most of the time, due to the H-Sync being different..  Everything on a TV needs overscan, as TVs always cut off about I think 5% of the picture all sides...

What's the TV model?  I have a list of service codes..

viletim

Quoteit's a bit distracting to see such a large amount of black space all around the image

Underscan. Overscan is where the picture is larger than the screen area.

There's probably nothing you can do about it short of replacing the LCD TV. If there are any more settings for video rendition it's unlikely they would be hidden in service mode.

The vast majority of SMS games run at a resolution of 256 * 192. Try finding that one in your HDTV standards book.

ken_cinder

#7
Actually viletim it's overscan. See - http://en.wikipedia.org/wiki/Overscan

Overscan is black area around a picture to compensate for unseen areas of a display, so the picture doesn't get cut off. This isn't an issue with LCD displays etc, so we see those areas that are designed to be off-screen.

Underscanning would ensure something is within viewable area without compensation. See - http://www.pcmag.com/encyclopedia_term/0,2...&i=53409,00.asp

BTW, I can get rid of the overscan by using the Letterbox feature on my TV, though it does stretch it a fair bit and it doesn't look as clean. TV model is Acer AT3200A BEW, I'd be mightily impressed if you had a code, because I haven't found anyone that does. Other Acer model codes don't work for it.

NFG

Overscan had real meaning in the old days where a CRT could actually expand or contract the image to fit the screen.  Consoles would often use overscan to control an image size or placement, but on an LCD the term has less meaning.

The LCD receives and samples the screen, and resamples it as required to make it fit the LCD frame (Which, unlike a CRT, has a fixed resolution).

So while it appears like overscanning, the TV is adding those borders because it is unable to stretch the image properly to fill the screen.  

viletim


IJTF_Cinder,

You are using the term ambiguously.

The when used in respect to a TV, the word overscan is used to describe ANY part of the active video signal which is displayed outside the visible screen boundary. The mistake you are making is confusing the overscan buffer area of a video signal (which the SMS does have) with the actual act of overscaning by a TV.

Underscanning is where ALL of video signal is visible on screen (including any overscan buffer), usualy with some wasted space or non-video garbage around it. This is usualy objectionable to most people, who whould rather waste some of the video content that see a border. Hence the reason why computers, games, etc introduced an overscan area into their video signal.

The colour of SMS the overscan area is selected by the game. It's often not black. So if you have a black area around your visible picture (with all games) then it's not related to the video and does't relate to anyscan.



smd4420

#10
that wiki article is a little confusing but overscanning as a verb is the process where the tv stretches the picture out beyond the edge of the screen. Underscanning as a verb is what ur tv is doing by which its not stretching the image far enough. Just like when "Studio monitors and camera viewfinders can be set to show the overscaned area, so that producers and directors can make certain it is clear." The overscan(area) as a noun is what ur seeing (the black borders that are annoying u). Its how the tv is built like u said u'll have to find a way in the service menu and adjust it. Or just learn to like it. But At least u kno nothing is being cut off of the screen. :P O and if its a sony i can give u instructions on how to get in the service menu its real easy.  

kendrick

I'm with Tim here. I understood overscan as the CRT term, to mean that areas of the image are outside of what is being displayed. If you see black borders and are not losing any of the image, then definitely an upscanner is your only real solution. It's not practical, but only external handling of the SMS video is going to make it work on your screen.

-KKC

blackevilweredragon

lawrence, LCD TVs have overscan options in their service menu, it's for NTSC/PAL sources usually, but they do have the option in them..  my 17" LCD HDTV (little table-top model), has this in it...

btw, here's the service menu codes for Acers..  I use bruzzi's list because it's so complete..

http://www.bruzziforum.com/vbf/showthread.php?t=90

ken_cinder

Doesn't work BEW, I can't hold any {UP} or {DOWN} button on the remote or TV itself and push the power button at the same time, doesn't do anything.
I've read his other threads at different forums, and he has a few specific service codes for certain Acer models.
One of them will allow me to get to a menu where I can see some technical details on my TV, but that's all.

I wonder if I email Acer if they'd give it to me.

blackevilweredragon

QuoteDoesn't work BEW, I can't hold any {UP} or {DOWN} button on the remote or TV itself and push the power button at the same time, doesn't do anything.
I've read his other threads at different forums, and he has a few specific service codes for certain Acer models.
One of them will allow me to get to a menu where I can see some technical details on my TV, but that's all.

I wonder if I email Acer if they'd give it to me.
For me to get my Prima's code, I had to badger them for a week before they gave me the code for my CRT HDTV..

I HAD to, too..  My CRTs geometry was WAAAAAAAY off, and they literally told me that to get it fixed, i had to drive to canada for it!  (im in florida).  i was insulted and told them to "Give me the damn code!!"

finally got it, and my TV has been great since :P

you might have to do that too, but don't get rude with them, someone like Acer may just hang up on you ;)

ken_cinder

I actually figured it out, it uses the same method as the 2720.

You select an input source and turn on the device using the source. Hold Power+Chan Up+Vol Down for 3 seconds and the screen flashes red. Then hit menu to access the service menu for that specific input (On Component for example, Ypbpr specific settings)

I got it to work, only problem is the damn thing won't stay on screen. It seems like the TV is cycling through all available inputs and I have to keep pressing the menu key, which of course brings up a different menu every time it's on a different source. Kinda hard to change settings on a menu that won't stay on screen for more than 2 seconds. Grrr.

blackevilweredragon

that's why service menus should only be used by technicians ;)

turn off the TV, unplug it for a bit, and plug it back in again..

ken_cinder

No issue, all I have to do is hit the power button while off a menu to restore factory defaults. I WANT to be able to use the service menus, but it's not letting me.