I did something like this before. The TFT display required an additional signal connector on the vga board. Check the vga board. Maybe it only "suppoorts" DSTN panels by native.

DAVE86 wrote on 2020-07-15, 09:23:

I did something like this before. The TFT display required an additional signal connector on the vga board. Check the vga board. Maybe it only "suppoorts" DSTN panels by native.

OK, that makes sense, i saw a photo of this screen on ebay and it has an extra ribbon connector, I have no way of knowing unless i pull apart the laptop, unless I can find a service manual somewhere.

Impossible

yes , its is possible on some laptops. For example, the service manual of a compaq LTE elite says that it's possible to upgrade from color DSTN or mono TFT to a color TFT display.

Looking at the part number chart, it says the (older) 220CDS can take a CSTN replacement and takes the same panel as the 300CDS.
Is a CSTN panel much better than a DSTN?
I might just look for another gaming laptop, I thought I was on to something with this, but never realised how bad these screens actually were!

Edit:

Link to (field) service manual talks about different connector for TFT or DSTN panel, im assuming it may be possible?
https://archive.org/details/toshiba-service-m … /mode/2up?q=tft

Also this sales brochure has this to say:

"All's clear: whether it's the DSTN or
TFT version, the 12.1" colour screen
will always keep you in the picture"

Would a TFT version have different brightness/contrast pots on the screen? The 8-bit guy did a video on this and said that TFT models usually only have one knob and that DSTN have 2, but my model is the opposite with just one brightness(or perhaps its contrast) wheel on the side of the display.

https://www.manualslib.com/manual/328855/Tosh … l?page=2#manual

Seems the 300CDT model has the TFT display, but would it likely have the same motherboard in both going by the service manual?
Connectors look the same on both types of panel

TFT panel is here
https://www.ebay.com/itm/LT121S1-105-LT121SS- … 4cAAOSw1bNd~KVs

DSTN panel

https://www.ebay.com/itm/Display-12-1-inch-80 … 5.c100752.m1982

Most of the Toshiba laptops set their brightness through a software utility. The wheel on the side of the display is for contrast and if it has that then it's pretty much always a DSTN panel.

I've done some looking into whether it's possible to swap panel types between models and while the boards are the same, there are a few differences.

For instance, I've got a Toshiba Satellite 2100CDT and 2140CDS laptop, they have the same mainboard but there are a few differences:
1. Both have a 12.1 panel but the panels used have different connectors in the display part
2. The CDS model has 2x LVDS chips near the display connector (a small thin & flat chip with about 40 small pins), one for each half of the screen, while the 2100CDT has just one
3. The display connector on the mainboard is the same, but the pinout is different because of the different LVDS configuration
4. Different video BIOS I Think? (edit: nah, should be the same BIOS)

I think it would be possible to swap the panel around if the LVDS chips were reconfigured to match the 2100CDT's configuration, but that would be a lot of soldering.

It's a similar situation for the 210CDS and the 210CDT. These have modular video cards that sit on top of the CPU board. The CDT has a different video card with more RAM and some different chips. THe video cards can be swapped between models. Last time I tried that I got a white screen, but I've since found that was a panel fault. Now I've got a working panel, I could potentially try again with my 430CDS

Thermalwrong wrote on 2020-07-16, 12:58:

Most of the Toshiba laptops set their brightness through a software utility. The wheel on the side of the display is for contras […]
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Most of the Toshiba laptops set their brightness through a software utility. The wheel on the side of the display is for contrast and if it has that then it's pretty much always a DSTN panel.

I've done some looking into whether it's possible to swap panel types between models and while the boards are the same, there are a few differences.

For instance, I've got a Toshiba Satellite 2100CDT and 2140CDS laptop, they have the same mainboard but there are a few differences:
1. Both have a 12.1 panel but the panels used have different connectors in the display part
2. The CDS model has 2x LVDS chips near the display connector (a small thin & flat chip with about 40 small pins), one for each half of the screen, while the 2100CDT has just one
3. The display connector on the mainboard is the same, but the pinout is different because of the different LVDS configuration
4. Different video BIOS I Think (haven't checked)

I think it would be possible to swap the panel around if the LVDS chips were reconfigured to match the 2100CDT's configuration, but that would be a lot of soldering.

It's a similar situation for the 220CDS and the 220CDT. These have modular video cards that sit on top of the CPU board. The CDT has a different video card with more RAM and some different chips. THe video cards can be swapped between models. Last time I tried that I got a white screen, but I've since found that was a panel fault. Now I've got a working panel, I could potentially try again with my 430CDS

OK, interesting.
It quotes the connector to plug the screen into in the service manual (PJ3 for DSTN and PJ23 for the TFT model) I was hoping the hardware may have already been on the motherboard to accomodate both models going by this.
I guess the only real way to know is to dismantle and check the chips.
The TFT screen is actually much cheaper anyway which is a bonus, but i guess I should look for a laptop with a 640x480 screen if i want the best picture anyway for DOS games?
FInding old laptops that still work is so difficult!

I wish I can do the contrary and change a TFT display for a DSTN .. Seriously the STN looks so vintage, I can't get why there's so much hate about them. The viewing angle is a lot better than the average TFT, they're a lot more relaxing for the eyes than the TFT's. But yes of course you won't play Quake or any fast moving games with them, but for anything else, I find them great.

Funny I found this today researching about doing the same sort of idea to my DFI MediaBook (NanTan 9200).

Anyway, I make NO claim to be an electronics expert. That said, I love tinkering with electronics and one of the reasons I play with old PC's like these...is because it's fun to see what I can do to bring them "up to speed". Yes, this will be one of my walls of text.

I've also been messing about a bit with upgrading a NanTan 9200 DFI MediaBook to TFT or at least DTSN. So I'll dump what I have so far here - might apply to Satellites.....I'm planning to put all this on my site once I'm done parsing everything and getting more pinouts from different panels from various laptops. There's a lot of 486 and 386 machines out there that I feel could possibly be at least hacked, if not legitimatley outfitted with some kind of TFT Color panel - at least anything with later chipsets that were liked up to a TFT.

I found this pinout chart here: https://www.instructables.com/Salvaging-Liqui … -Displays-LCDs/ - I spent hours looking for a Datasheet for the Casio MD820TT00-C1 found in the DFI and came up empty handed, but looking at photos on e-bay, I noticed most STN Monochrome Laptop displays have the same pinout of 14-16 pins, depending on if the CFLs are powered by an on-board ballast board or a separate one like my DFI does.

Quick and Dirty Version of STN Mono Pinout per the site above
1 - Ground
2 - +3 or +5 Volts
3 - Contrast Adjustment
4 - Register Select Signal (RS)
5 - Read/Write Select Signal (Low = Read, High = Write)
6 - Enable Panel Signal
7 - Data 0
8 - Data 1
9 - Data 2
10 - Data 3
11 - Data 4
12 - Data 5
13 - Data 6
14 - Data 7
15 - Backlight Anode (optional)
16 - Backlight Cathode (optional)

Now, what this means is you can't just simply slap on a color panel and have it work. But......

I own four NEC Versa Laptops (40EC, V/50, M/75, and P/75) - ALL Active Matrix - and one DFI MediaBook (NanTan FMAK9200) - STN Monochrome and likely a similar pinout sans pins 15 & 16- and a common thread I Found between these two is that the wiring that comes off the motherboard/connector board (the part on the detachable screen Versas that attaches the screen to the motherboard), is that they BOTH have 3-wire connectors going to the screen's controller boards to the screen assembly. The connectors for the Versa darn-near almost match the ones for the DFI.

On the Versas - There are 34 pins total across 3 connectors for the TFT Active Matrix Panels (NL6448AC30-03/06/10, NL6448AC30-09 - which is a special case - I'll get to in a moment, and the NL8060AC24-01 which is the 800x600 panel used in the M/75 and P/75HC models). These laptops (save for the Versa V series) had detachable screens that could be swapped with STN Monochrome, DTSN Color, and Active Matrix TFT - with later models being capable of using higher resolution panels as an extra multiplexer chip with capacitor was wired into the connector board. The special case was the VErsa M/75TC and M/100TC (PC-570/580) - which used a special controller board (the M/75's had interchangeable LCD Controller boards on the system planar), and used a special True-Color panel with slightly different wiring but it still had 3 connectors. The panel had extended logic for the higher color range built in. This means that the RAW signals were coming off the Versa boards from the C&T/WD chipsets - and then being sent to the screen, where the signal was handled with the on-board electronics. I took another look at Beige-O-Vision's video on the V/50 he tore apart - which had DTSN Color - and I saw that the Kyocera panel in his V/50 had a larger control board on the right side of the panel - did not get a good look at the wiring harness though - but I See it's the same single connector on the Versa base-unit side as my V/50C which has an active matrix NL6448AC30-10 panel.

On the DFI - the three connectors attach to the motherboard and run through the hinges - and connect to a special circuit board that seems to "reduce" the signal down to something the Casio panel understands, which has only 14 wires, as well as provides power to the board for several chokes and a Ballast transformer that powers the CFL backlight.

Now, talking TFT signals vs. STN Signals - STN, DTSN, and TFT seem to share the same signals for power and data enable, though TFTs tend to have extended functions. The NEC Panels are well documented and have a good sheet - and the NL6448AC30-03 is compatible with the 06 and 10 models - I know because I've switched these out (you can also upgrade the M and P models to 800x600 if they were original 640p by adding a 500K resistor to the connector board, or removing it to go back to 640x480). IT seems TFTs tend to use raw-signals off the motherboard, doing the work themselves, while STN and DTSN tend to use a separate ballast/control/reducer circuit of some kind to allow for the screen to manage a reduced amount of data lines.

The NLxxxxxx panels I listed all have three connectors: the first a 10 pin containing Clock, 3 grounds, Horizontal and Vertical sync lines, and the Red Data, a 13 pin containing more grounds, Ac Adapter in, Backlight on/off, and the data lines for Green and Blue, and a 11 pin used for backlight power, data enable, mode, vcc on/off, logic power, and of course, more grounding lines. Basically the pinout is

CN1
1 - CLK
2 - GND
3 - GND
4 - Hsync
5 - Vsync
6 - GND
7 - Red Data 0 (LSB - Left Side Bus?)
8 - Red Data 1
9 - Red Data 2
10 - Red Data 3 (RSB - Right Side Bus?)

CN2
1 - GND
2 - Green Data 0 (LSB)
3 - Green Data 1
4 - Green Data 2
5 - Green Data 3 (RSB)
6 - GND
7 - Blue Data 0 (LSB)
8 - Blue Data 1
9 - Blue Data 2
10 - Blue Data 3 (LSB)
11 - Ground
12 - AC Adapter In
13 - Backlight On/Off

CN3 - 11 Pin
1 - GND
2 - VCC - Voltage, Logic
3 - VDD - Voltage, Backlight Circuit
4 - VDD - Voltage, Backlight (2nd for 03/06)
5 - NC
6 - GND B - Backlight Ground
7 - GND B - Backlight Ground
8 - Data Enable
9 - Mode
10 - VCC power Off (power saving?)
11 - GND

So as we can see - ALL the voltages are self contained on these NEC Panels - now I know this thread is not about NEC - but hopefully this will help trace down what can done as IBM, Toshiba, Compaq, and any other laptop computer uses the same wiring, principles, and general lines. Honestly, I wish I had an oscilloscope so I Could capture the data/waveforms off the connectors and possibly come up with a way to reverse engineer my DFI using those as a guide - as the DFI has more connectors (likely just more grounds).

And the idea/hypothesis that I have that the TFT signals come raw off the chip is further supported by the position of the graphics controller chip on both laptops. The NEC's have the same connector in roughly the same place on ALL models from the original Ultralite PC-400 20MHz all the way to the P/75 - just different chips, but they use the same data lines and it seems there's not more than filtering and possibly some resistance added before they go to the screen connector plug.

I also found the pinout to another LCD Panel - this time DTSN - to get an idea what the data/power/control structure of these panels would be compared to the other two. Most of these old Laptops use industrial LCD panels (shame they're so expensive) - the NEC NL-series panels are used in other things than just Versa Laptops (expecially the NL6448AC30-12 which seems to use a standard connector similar to many TFT panels I've looked at, and appears to also require a separate ballast connector for the CFLs).

SHARP LM64C031
640x480 9.4" LCD Single Scan STN

CN1 - 18 pin
1 - Startup
2 - Latch Data
3 - Lower Data Clock
4 - Upper Data Clock
5 - NC
6 - Power SUpply, Logica & LCD +5v
7 - Ground
8 - Power Supply for LCD
9 - Ground
10 - Data 0
11 - Data 1
12 - Data 2
13 - Data 3
14 - Data 4
15 - Data 5
16 - Data 6
17 - Data 7
18 - Ground

CN2 - 6 pin for CCFL
1 - High Voltage Line for CCFL (From Inverter)
2 - nc
3 - GND
4 - GND
5 - NC
6 - Hight Voltage Line (From Inverter)

Being passive matrix, looks like it uses similar data structure (8-bit) to the STN Monochrome panel, with the additional lines for Latch, separate data clocks for lower and upper (Thoguh that could just be another term for the Register Select), and a few more grounds.

Hopefully this is helpful information - this is what I have so far.

You have to check the datasheet of the used vga controller, when there is support for tft, it most likely can be done. Sometimes you have to patch the bios.

I have been wanting to do this as well with some of my laptops, so this is a useful thread. I don't know a lot about the details though. A hard part to consider is obtaining a compatible screen, since you will usually just be buying another laptop. Luckily those Toshiba's are relatively cheap and are quiet common. Would you like me to inform you if I come across a cheap faulty cdt-model?

I did this recently with a Toshiba 410CS which used the screen from a dead 430CDT. It was a success and although I thought it would require changing the BIOS from a CS to CT model, that wasn't necessary.

On the toshiba laptops that have the one speaker on the front (Satellite 100 to 110, 200 to 220 and 400 to 430, with CS, CDS, CT, CDT suffixes) - the difference between the TFT and DSTN models is specifically the screen itself, and the video card that plugs onto the motherboard. I was able to take the video card from a CT laptop, along with its screen and put it onto the CS laptop, which now saw itself as a TFT model and works without issue.

Even better than that, since I've got more than one of these and had some time a few weeks ago, along with some chipquik SMD removal solder - I was able to take the components from a damaged 'CT' model's video card and put those onto a 'CS' model's video card, moving around resistors and capacitors to match. That worked too!