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New TFT Display for a Toshiba T5200?

I know this has been brought up already, but it's sort of notable that if you search for the part number of the LCD panel you'll find a couple articles (including a reference to a research paper) that say that it's the *first* commercial VGA color LCD. With that in mind are you *sure* you want to continue? It may not objectively be any good but it is *special*...
 
I think he's pretty determined. But it is quite rare, I think most people got the plasma version for the crisp display, and used an external for when they needed color (hence the removable screen).
It would be pretty nice with a perfect fit, using the internal connectors, and if those brightness/contrast controllers could be used though. It'd feel authentic and be nice to look at.

I'm curious about the display - I see in the pictures the connector and mounting looks identical to the plasma T5200.
 
Yes, i found that article myself and thought exactly the same as you. This display is a piece of computing history and, you know, it does a pretty decent work for its age. Replacing it with a new cheap led tft display would be a shame. I think i will save this one for another repair. By the way, the ieee article is very interesting on how it describes the technology.
 
inakito said:
Yes, i found that article myself and thought exactly the same as you. This display is a piece of computing history and, you know, it does a pretty decent work for its age. Replacing it with a new cheap led tft display would be a shame. I think i will save this one for another repair. By the way, the ieee article is very interesting on how it describes the technology.
Click to expand...

Good decision
 
inakito said:
Yes, i found that article myself and thought exactly the same as you. This display is a piece of computing history and, you know, it does a pretty decent work for its age. Replacing it with a new cheap led tft display would be a shame. I think i will save this one for another repair. By the way, the ieee article is very interesting on how it describes the technology.
Click to expand...

Yeah good decision.

It has inspired me a bit though. I have a T3200SX with a dead plasma display - when I get an oscilloscope and more time I'll have to give this idea a try.
 
For your viewing pleasure, a comparison between the old T5200 LCD color display (just 16 colors!) against the same computer using an external VGA monitor: (picture "Monkey Island 2").

mi_t5200.jpg
 
The lcd display has only 16 colors, while the picture has 256 palettized colors. There is no chance the colors would match. Even worse, i have checked that the palette changes do not affect the internal lcd output, so it seems the 16 colors are fixed.
 
From on objective standpoint obviously the quality is terrible, but from a historical point of view that's fantastic. If you wanted to show a young person just how far technology's come in just the last two decades that's a heck of a demonstration.

(I would be curious to see a screenshot of how the screen looks when it's displaying 16 color (CGA palette) text or high-resolution graphics, I assume the screen is most optimized for that. At least the backlighting on this looks pretty even, unlike the worst examples you'd see of those side-lit "Dual Scan" displays from the mid-90s.)
 
Eudimorphodon said:
From on objective standpoint obviously the quality is terrible, but from a historical point of view that's fantastic. If you wanted to show a young person just how far technology's come in just the last two decades that's a heck of a demonstration.

(I would be curious to see a screenshot of how the screen looks when it's displaying 16 color (CGA palette) text or high-resolution graphics, I assume the screen is most optimized for that. At least the backlighting on this looks pretty even, unlike the worst examples you'd see of those side-lit "Dual Scan" displays from the mid-90s.)
Click to expand...

Yeah, I wanna see it display some ansi art or something.
 
This is a demo at 640x480 16-colors. Not bad! (the left display is the internal display; the right one is an external VGA monitor).

PieChart.jpg
 
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This is a color chart demo. Note the shadows around the rectangles, as they look on the display, these are not photo side effects.
(on the right the same display on a VGA monitor).

Colors.jpg
 
inakito said:
This is a color chart demo.
Click to expand...

It's interesting how that demo seems to reveal that the LCD in this machine is actually only capable of producing 8 colors, not 16. (Or, at least, that it has very little dynamic range between "bright" and "dark" for every color except white/gray) On the LCD screenshot the colors appear to repeat starting from index #9. The only "unique" color on its version of the chart is #8, which on a digital CGA monitor would be the "bright black" gray. (On CGA you get four "grayscales", IE, "dark black", "bright black", "dark white", and "bright white". #7 and #15 should be dark and light white respectively, but they look the same.)

(It would be interesting to play with putting colored text on a colored background, and see, for instance, if you can read "bright white" text on a "dim white" background. You should be able to on a "real" monitor, I'm curious if this machine will render this invisible, or if the LCD controller will play games with color substitution to make it show despite the limitations of the screen.)
 
I have found the contrast dial is critical so two color may look the same with contrast below 80%.

Attached is a picture that contains the following tests:

- The first one is text mode dump with the following colors: 1 over 9, 2 over 10, 3 over 11 and 5 over 13. Depending on the area of the screen you can see clearly the character over the background.
- The second picture is the same on an VGA external monitor. Here the contrast is better, except perhaps the brightness is too high (my fault).
- The third one is the color chart shown in my previous post but with the same contrast setting used on picture one (contrast above 80%).

So, I would say the display is capable of showing 16 colors, but only with very high contrast settings.

triptic.jpg
 
Ohhhhh, that's so awesome, pictures of the T5200C screen! I'm honored just to have seen such a rare thing! And that article elmatero posted - the T5200C/100 is just overflowing with awesomeness :D
 
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