A new toy today

[shorthair]

I'm not sure this is worth posting due to the quality of my pictures, but I'll post and  update the pictures, later.

I just today got this 27" Monivision presentation monitor. I got it for $50 on ebay. The shipping was about twice that, but as this thing is (supposedly) 140 lbs (wasn't able to carry it from the car, but hoisting it from floor to desk was less problem than I thought, though not necessarily recommended), it was actually cheaper (and easier) for them to send it freight on a pallet and me pick it up several miles away in town, than it was to have UPS or Fedex ship it.

The first thing about it is that it's in superb shape. No scratches, very little dirt. (I cleaned it, of course, anyways.) Turn it on. Nice picture...but, though it's set at XGA, same as the arcade monitor, the picture isn't as sharp. Everything in the menu except convergence. Hmm.  I look closely...compare it with my Billabs. Hm - the Billabs is actually a finer dot pitch. Curious. As I like very high res graphics, I prefer using this monitor with Mame D3D with bilinear filtering off. Then it's about as crisp as the Billabs - in Mame - but, of course, the color is different. An arcade monitor, or at least mine, even outside of native resolutions appears to present richer colors. Lighter, yes richer. Greater depth, perhaps.

Next we have the audio. For anyone using a TV outside of a cabinet, this is a feature one might like. Not only does this have stereo speakers. It has a sub - as well as bass and treble controls in the menu. Kicks decent ass. The fidelity is pretty good...though I tend to fancy my Harman-Kardon 2.1 system that came with my old Dell.

On the back, it's a little circumspect in it's video-in features. VGA in (and out), S-video, and composite (A/V). There's also inputs on the front behind the little door below the display.

What's really funny is the viewable area looks smaller than the tube of the Billabs. But it's actually a half inch or so bigger. Something about a flat display, I think. But the image is noticably bigger to me cos of the slightly larger dot pitch.

Anyways, all-in-all, a good buy so far. Worth it just for the experience. (Of course, I now have two large monitors....)

[fjl]

So what is it? An arcade monitor? 

[Shmup-o]

holy carp, no wonder you're excited  ...

Monovision Presentation monitor

[shorthair]

holy carp, no wonder you're excited  ...

Monovision Presentation monitor

Except mine is a little older, as it's a curved screen. But it's pretty neat. It doesn't do a lot of resolutions through my avga, though vector games with 'switchres' look cool...Tempest and Black Widow are pretty brilliant...though vectors look pretty good, regardless. Raster graphics are just slightly undefined with DD - RBG sharp. Some of you might really like it for that reason, especially without it. Hopefully will have a better camera soon to show some decent screen shots.

[Havok]

Nice find. Perhaps you can make a vector only cab? Vector games are my personal favorites, with the exception of Robotron...

[Freeplay]

Nice score......
I got 3 of those monitors off ebay for $200aud about 6 months ago.
They are perfect for mame cabs... vga in and go.

[ChadTower]

I have a similar monitor, different maker... great, great unit.  Got mine off Freecycle.

[tetsu96]

Large monitors are cool in general, and great for low res PC games or MAME.  The scan range on the one that was linked only went down to 31KHz so not the best for purists, this one I imagine also is the same as the AVGA can't run games natively.

A purist would be put off by that, but if you're not as critical, then it's definately swank (especially for the price).  Good find.

[shorthair]

Havok: that is tempting, though the raster presentation of graphics and colors is plenty good enough...good enough that I'm probly just being a little fussy about that part. If don't compare it to my arcade monitor (and the difference, though perceptible, is not that great) and just take it for what it is, it's DAMN good. Hell, sometimes, just in being able to play these games on decent monitors just makes me feel good.

[AlexKidd]

One thing to note on these presentation type monitors. If they have a built in scan converter that lets you run the monitor at resolutions that are not native to the screen sometimes it can do weird things. Some Games create transparency by making graphics invisible every other frame. Mame handles this fine but scan converters will sometimes drop frames or only show every other frame and what ends up happening is the graphic disappears when you are suppose to see a semi transparent graphic, or graphics that should be transparent stay solid. This is used a lot in games where you become invincible for a time when you get hit.

I have a 32inch zenith presentation monitor that this was happening on and it took me the longest time to figure out what was going on. Luckly the front VGA input didn't go through the scan converter, the picture looks better from the front input too. 

Something to keep an eye out for.

[shorthair]

Hmmm.  I was kinda curious about the image quality. It turns out the image appears to get a little clearer and brighter through the front.  I totally forgot to check it, partly as I prefer it connected in the rear, and right now I'm just using a table for both monitor and panel, and am off the table as it is. Thanks.

[Zebidee]

Hi Shorthair,

What frequencies are you sending to the monovision?  VGA or something else?

I was just looking at the monovision specs and wondering ...

I think that because it is 31khz, it does a little line doubling trick to do 15khz modes.  That is, because it draws the lines twice as fast, it must draw twice as many lines to keep the vertical frequency at 50-60khz.  It says in the specs "31khz", "Resolution (Line Doubler)" and that it does "1050 Lines (NTSC) or 1250
Lines (PAL)", which is about twice as many as normal for these modes.

Clearly, the VGA 15-pin D-Sub was designed for laptops etc.

So, I'm also curious about what the picture quality is really like.  I think that these things were mainly used when people wanted to be able to display both laptop presentations and also TV/video.  It sounds like some kind of scan converter or similar is used, as it would have to add lines to 15khz input.  Alexkidd's comments seem to reflect that.  Are they actually good for mame resolutions?  Or are they really just a kind-of VGA monitor with a scan converter built in?

[RandyT]

So, I'm also curious about what the picture quality is really like.  I think that these things were mainly used when people wanted to be able to display both laptop presentations and also TV/video.  It sounds like some kind of scan converter or similar is used, as it would have to add lines to 15khz input.  Alexkidd's comments seem to reflect that.  Are they actually good for mame resolutions?  Or are they really just a kind-of VGA monitor with a scan converter built in?

There are a couple of types of monitors out there.  The ones to look for are actual large multi-sync monitors.  These will have a native ability to switch to different frequencies, usually VGA and lower, in order to display the information as it is received.  They would be comparable to the WG D9200 / D9400 types of monitors.

The other type are, unfortunately, just video monitors with a built in down-scaler.  Internally, they are most likely an S-video monitor, with the Composite and S-video passing straight through from the inputs.  The 15-pin D-sub would go to the scaler circuitry and then to another of the units S-Video inputs.  These units may or may not have special tubes to allow more "lines" of resolution.  The value of higher than 800 lines on a video monitor is questionable.

The sometimes difficult part is knowing which one is which when it comes to "Presentation Monitors" as to be one, it pretty much just needs to put an image on a large screen from a number of different inputs.  To meet that goal, one could just as easily attach a composite / s-video input conversion board to D9400, as one could attach a down-scaler to a TV monitor.  Fortunately, the documentation will sometimes provide clues as to whether the input is scaled and in which direction.  The word Multi-Sync and the presence of RGBS inputs usually means good things though.

I personally own and have used down-scalers and Multi-sync monitors.  There is no comparison between the two.  Scalers almost always exhibit artifacting in the way of tearing on scrolling games or some other undesirable result.  It's possible that the circuitry built into the monitors is better than the less-expensive stand-alone boxes, but there's no way to know unless you are able to actually test it and observe what happens.

RandyT

[Zebidee]

Wow.  Thanks!

[shorthair]

I didn't do a lot of searching, but I could only get the main specs. I think it's the latter, Zeb. And possibly like what Randy said, though I don't know about the d-sub going through the S-video, as the rear input image is actually really good - only slightly less defined than the front input, which is about as good if not the same as my Billabs, both set at XGA.

Like I've said, I don't prefer scan lines, so this monitor does fine for me. It is curious it will do vectors at apparently the same quality as my Billabs (both through my avga), though the former does this snapping back of the image, a sort of balloon snapping back and forth, then stabilising (vs the sorta schizo effect the Billabs, and apparently any multi-sync, goes through) when exiting a game back to the desktop. I wonder if I might hurt the Monivision by using switchres even with those games?

[shorthair]

A sort of update on this, if anyone's interested. I hadn't fully tested native resolutions with the Monovision. I knew it wouldn't do 15 or 25 khz, but wasn't sure if it was actually doing some sort of native-like thing when connected to the DVI port of the AVGA. Turns out it does, and registers the image geometry settings in different modes. Some are some pre-defined mode, whereas others are 'user mode', just like my Billabs (or a Betson) will say depending on what res it's set for in Mame.