renejr902 wrote on 2025-04-08, 06:10:

Hi! […]
Show full quote

Thermalwrong wrote on 2024-10-14, 18:26:

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling op […]
Show full quote

renejr902 wrote on 2024-10-14, 17:05:

Another thing. Do you know a way to have Keen4 not fullscreen stretching ? with black border in top and bottom instead ? I changed text stretching in bios but it changed nothing about that. It works with top and bottom black border with my compaq Elite cx4/50 wuth a 9.5" 640 x 480 lcd screen. But anyway i think i still prefer it fullscreen stretched because its really 4/3 aspect ratio to my eyes and i think its the good and authentic mode to play it, but i'm still curious about it.

( read my previous post before thanks 😀 )

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling options than the CT65546 that the 400CDT originally had. There's a utility called VEXP which can control the scaling behaviour with more detail than the BIOS LCD stretch setting.
It's on the internet archive but since that's down right now you can get it here: http://retro.timb.us/Systems/Toshiba_Libretto/Drivers/DOS/
Have a read of the .txt file which explains its usage, it should be run before windows or when booted into command line mode.

A couple more things:
1. If you want to install an RTC battery in place of the original rechargeable, be aware that the laptop puts 5v into those RTC pins when the laptop is on. That means it would be dangerous to install a CR2032 (non rechargeable) without protection.
You can run the laptop just fine without an RTC battery and just reset the BIOS options each session. If you do want the RTC battery then the simple way that I do it is to use a CR2032 but put two 1n4148 diodes in series so that power can go out of the cell but the laptop can't charge the coin cell.
2. The inverter is the same on both, it's model UA0392P01 which is used on the whole T21xx series and the Satellite Pro 400 to 430 models.

Hi!

I have a few question thanks.

1. Is it ok to use a ML2032 rechargeable battery instead ? ( with a cr2032 socket in the 400cdt) ( if they send 5v i suppose its not a good idea ) ( edit: i just checked the maintenance manual its a 3.6v battery that was there. )

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

2. Why is the 400cdt lcd screen in my 420cdt stretch commander keen6 game in fullscreen ( with text stretching on or off in bios ) But with a 400cdt the original lcd screen will make a top and bottom black border in keen6 ( with text stretchimg on or off) I would prefer fullscreen without black border with my 400cdt.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

3. Do you know if the 400cdt lcd screen will be compatible with a Toshiba 2150cdt laptop ? ( and the other way too ? )

Thanks a lot.

Yep, those are both the LTM10C021 LCD panels 😀

Thermalwrong wrote on 2025-04-08, 13:13:

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and […]
Show full quote

renejr902 wrote on 2025-04-08, 06:10:

Hi! […]
Show full quote

Thermalwrong wrote on 2024-10-14, 18:26:

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling op […]
Show full quote

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling options than the CT65546 that the 400CDT originally had. There's a utility called VEXP which can control the scaling behaviour with more detail than the BIOS LCD stretch setting.
It's on the internet archive but since that's down right now you can get it here: http://retro.timb.us/Systems/Toshiba_Libretto/Drivers/DOS/
Have a read of the .txt file which explains its usage, it should be run before windows or when booted into command line mode.

A couple more things:
1. If you want to install an RTC battery in place of the original rechargeable, be aware that the laptop puts 5v into those RTC pins when the laptop is on. That means it would be dangerous to install a CR2032 (non rechargeable) without protection.
You can run the laptop just fine without an RTC battery and just reset the BIOS options each session. If you do want the RTC battery then the simple way that I do it is to use a CR2032 but put two 1n4148 diodes in series so that power can go out of the cell but the laptop can't charge the coin cell.
2. The inverter is the same on both, it's model UA0392P01 which is used on the whole T21xx series and the Satellite Pro 400 to 430 models.

Hi!

I have a few question thanks.

1. Is it ok to use a ML2032 rechargeable battery instead ? ( with a cr2032 socket in the 400cdt) ( if they send 5v i suppose its not a good idea ) ( edit: i just checked the maintenance manual its a 3.6v battery that was there. )

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

2. Why is the 400cdt lcd screen in my 420cdt stretch commander keen6 game in fullscreen ( with text stretching on or off in bios ) But with a 400cdt the original lcd screen will make a top and bottom black border in keen6 ( with text stretchimg on or off) I would prefer fullscreen without black border with my 400cdt.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

3. Do you know if the 400cdt lcd screen will be compatible with a Toshiba 2150cdt laptop ? ( and the other way too ? )

Thanks a lot.

Yep, those are both the LTM10C021 LCD panels 😀

Thanks so much for this utility 😀

Thanks so much for these answers, its really appreciated ! 😀

The stretching utility works perfect ! 😀

Thermalwrong wrote on 2025-04-08, 13:13:

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and […]
Show full quote

renejr902 wrote on 2025-04-08, 06:10:

Hi! […]
Show full quote

Thermalwrong wrote on 2024-10-14, 18:26:

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling op […]
Show full quote

Well this is the really cool thing about your mod, it combines the vga LCD with the CT65550 video card which has more scaling options than the CT65546 that the 400CDT originally had. There's a utility called VEXP which can control the scaling behaviour with more detail than the BIOS LCD stretch setting.
It's on the internet archive but since that's down right now you can get it here: http://retro.timb.us/Systems/Toshiba_Libretto/Drivers/DOS/
Have a read of the .txt file which explains its usage, it should be run before windows or when booted into command line mode.

A couple more things:
1. If you want to install an RTC battery in place of the original rechargeable, be aware that the laptop puts 5v into those RTC pins when the laptop is on. That means it would be dangerous to install a CR2032 (non rechargeable) without protection.
You can run the laptop just fine without an RTC battery and just reset the BIOS options each session. If you do want the RTC battery then the simple way that I do it is to use a CR2032 but put two 1n4148 diodes in series so that power can go out of the cell but the laptop can't charge the coin cell.
2. The inverter is the same on both, it's model UA0392P01 which is used on the whole T21xx series and the Satellite Pro 400 to 430 models.

Hi!

I have a few question thanks.

1. Is it ok to use a ML2032 rechargeable battery instead ? ( with a cr2032 socket in the 400cdt) ( if they send 5v i suppose its not a good idea ) ( edit: i just checked the maintenance manual its a 3.6v battery that was there. )

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

2. Why is the 400cdt lcd screen in my 420cdt stretch commander keen6 game in fullscreen ( with text stretching on or off in bios ) But with a 400cdt the original lcd screen will make a top and bottom black border in keen6 ( with text stretchimg on or off) I would prefer fullscreen without black border with my 400cdt.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

3. Do you know if the 400cdt lcd screen will be compatible with a Toshiba 2150cdt laptop ? ( and the other way too ? )

Thanks a lot.

Yep, those are both the LTM10C021 LCD panels 😀

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part of the screen all white.( its from a 400cdt ltm10C021 "P02"
( i exchanged the fluorescent lamp with a good one and i exchanged the inverter with a good one. and it does not change anything )

I have another same model panel that backlight is dim its ltm10C021 "P01" from a t2150cdt. i tried the same thing, i changed the fluorescent lamp with a good one and i exchanged the inverter with a good one and it does not change anything too. not a slim difference, still dim

by the way i dont know the difference between
ltm10C021 "P01" and "P02" ( its the end of the other number written on the panel )

Thanks for advice or help. I will ask my father tomorrow to check the one that miss the bottom part of the screen that is all white.

I keep my best LCD screen model ltm10C021 "P02" in my Pentium 100mhz 420cdt. On the 420cdt the panel backlight is a little bit stronger and colors are more colorful and vivid than when this panel was installed on the 400cdt or t2150cdt, i tested both. its really a little better on the 420cdt ( i think because the videocard is better )

renejr902 wrote on 2025-04-09, 10:09:

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part o […]
Show full quote

Thermalwrong wrote on 2025-04-08, 13:13:

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and […]
Show full quote

renejr902 wrote on 2025-04-08, 06:10:

Hi!

I have a few question thanks.

1. Is it ok to use a ML2032 rechargeable battery instead ? ( with a cr2032 socket in the 400cdt) ( if they send 5v i suppose its not a good idea ) ( edit: i just checked the maintenance manual its a 3.6v battery that was there. )

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

2. Why is the 400cdt lcd screen in my 420cdt stretch commander keen6 game in fullscreen ( with text stretching on or off in bios ) But with a 400cdt the original lcd screen will make a top and bottom black border in keen6 ( with text stretchimg on or off) I would prefer fullscreen without black border with my 400cdt.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

3. Do you know if the 400cdt lcd screen will be compatible with a Toshiba 2150cdt laptop ? ( and the other way too ? )

Thanks a lot.

Yep, those are both the LTM10C021 LCD panels 😀

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part of the screen all white.( its from a 400cdt ltm10C021 "P02"
( i exchanged the fluorescent lamp with a good one and i exchanged the inverter with a good one. and it does not change anything )

I have another same model panel that backlight is dim its ltm10C021 "P01" from a t2150cdt. i tried the same thing, i changed the fluorescent lamp with a good one and i exchanged the inverter with a good one and it does not change anything too. not a slim difference, still dim

by the way i dont know the difference between
ltm10C021 "P01" and "P02" ( its the end of the other number written on the panel )

Thanks for advice or help. I will ask my father tomorrow to check the one that miss the bottom part of the screen that is all white.

I keep my best LCD screen model ltm10C021 "P02" in my Pentium 100mhz 420cdt. On the 420cdt the panel backlight is a little bit stronger and colors are more colorful and vivid than when this panel was installed on the 400cdt or t2150cdt, i tested both. its really a little better on the 420cdt ( i think because the videocard is better )

Huh, interesting point about the colour rendition on the 420CDT versus the 400CDT, the newer chip probably has better FRC / dithering than the 400CDT's video chip 😀

I have no idea what the P01 or P02 mean, sorry. Probably just minor production improvements or to signify that it's for a different laptop model. It did get used on the T4900CT, T2150CDS/CDT and the 400CDT so they probably used the VF0131P02 code for the 400CDT. The fact that you see a difference in brightness does suggest to me that perhaps they changed how the backlight section is made, with improvements to the fresnel sheets or acrylic. Or maybe the LCD itself is different and the later screen's transistors are more transmissive of light. Earlier TFT LCDs like the ones on the T4400SXC for instance need huge backlights with dual lamps and they're still pretty dim, later TFTs made big improvements there.

The bottom row driver failing to work on the LTM10C021 seems to be a common fault and a design flaw, with the damage probably resulting from a drop or knock where the LCD glass moved but the row driver board is screwed down so it didn't move, resulting in broken traces to the last row driver.

Check this out, I got an LTM10C021 LCD in that looked like this:

Reconnecting the connectors on the back made it look like this instead, same as your one now:

Taking the panel apart, I found that all the traces for the bottom row driver or CoF (chip on film) were severed, zoom in and you can see that the first and last set of six pins go nowhere. In this pic I first of all cleaned off the broken parts of the traces and cleaned the flux. Then put fresh solder onto what was left of the CoF's traces and put some fresh flux & solder on there. It was enough to connect up the middle 17 pins and reconnect the CoF to the LCD's row driver PCB:

Now it looks like this, just one broken line when displaying green which is pretty usable still:

Your LCD looks to be in better shape than mine was so it probably won't have any vertical stripes 😀

Thermalwrong wrote on 2025-04-09, 13:41:

Huh, interesting point about the colour rendition on the 420CDT versus the 400CDT, the newer chip probably has better FRC / dith […]
Show full quote

renejr902 wrote on 2025-04-09, 10:09:

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part o […]
Show full quote

Thermalwrong wrote on 2025-04-08, 13:13:

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and […]
Show full quote

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

Yep, those are both the LTM10C021 LCD panels 😀

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part of the screen all white.( its from a 400cdt ltm10C021 "P02"
( i exchanged the fluorescent lamp with a good one and i exchanged the inverter with a good one. and it does not change anything )

I have another same model panel that backlight is dim its ltm10C021 "P01" from a t2150cdt. i tried the same thing, i changed the fluorescent lamp with a good one and i exchanged the inverter with a good one and it does not change anything too. not a slim difference, still dim

by the way i dont know the difference between
ltm10C021 "P01" and "P02" ( its the end of the other number written on the panel )

Thanks for advice or help. I will ask my father tomorrow to check the one that miss the bottom part of the screen that is all white.

I keep my best LCD screen model ltm10C021 "P02" in my Pentium 100mhz 420cdt. On the 420cdt the panel backlight is a little bit stronger and colors are more colorful and vivid than when this panel was installed on the 400cdt or t2150cdt, i tested both. its really a little better on the 420cdt ( i think because the videocard is better )

Huh, interesting point about the colour rendition on the 420CDT versus the 400CDT, the newer chip probably has better FRC / dithering than the 400CDT's video chip 😀

I have no idea what the P01 or P02 mean, sorry. Probably just minor production improvements or to signify that it's for a different laptop model. It did get used on the T4900CT, T2150CDS/CDT and the 400CDT so they probably used the VF0131P02 code for the 400CDT. The fact that you see a difference in brightness does suggest to me that perhaps they changed how the backlight section is made, with improvements to the fresnel sheets or acrylic. Or maybe the LCD itself is different and the later screen's transistors are more transmissive of light. Earlier TFT LCDs like the ones on the T4400SXC for instance need huge backlights with dual lamps and they're still pretty dim, later TFTs made big improvements there.

The bottom row driver failing to work on the LTM10C021 seems to be a common fault and a design flaw, with the damage probably resulting from a drop or knock where the LCD glass moved but the row driver board is screwed down so it didn't move, resulting in broken traces to the last row driver.

Check this out, I got an LTM10C021 LCD in that looked like this:

The attachment LTM10C021-repair (1) (Custom).JPG is no longer available

Reconnecting the connectors on the back made it look like this instead, same as your one now:

The attachment LTM10C021-repair (2).JPG is no longer available

The attachment LTM10C021-repair (3).JPG is no longer available

Taking the panel apart, I found that all the traces for the bottom row driver or CoF (chip on film) were severed, zoom in and you can see that the first and last set of six pins go nowhere. In this pic I first of all cleaned off the broken parts of the traces and cleaned the flux. Then put fresh solder onto what was left of the CoF's traces and put some fresh flux & solder on there. It was enough to connect up the middle 17 pins and reconnect the CoF to the LCD's row driver PCB:

The attachment ltm10c021-bottom-row-driver-repair.jpg is no longer available

Now it looks like this, just one broken line when displaying green which is pretty usable still:

The attachment LTM10C021-repair (4) (Custom).JPG is no longer available

Your LCD looks to be in better shape than mine was so it probably won't have any vertical stripes 😀

Wow Nice, impressive, thanks for all these information. You're the king here on vogons 😀
Thanks so much

Thermalwrong wrote on 2025-04-09, 13:41:

Huh, interesting point about the colour rendition on the 420CDT versus the 400CDT, the newer chip probably has better FRC / dith […]
Show full quote

renejr902 wrote on 2025-04-09, 10:09:

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part o […]
Show full quote

Thermalwrong wrote on 2025-04-08, 13:13:

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and […]
Show full quote

Honestly, not sure, I've never tried it. It might not be safe because as you've observed the laptop tries to charge it at 5v and I don't think that's got a smart charging circuit.
My preference currently is to use a CR2032 but hook it into the RTC connector through 2x 1n4148 diodes so it can't be charged by the laptop. Lots of voltage drop but it does seem to work.

That's because the 400CDT's bios setting to enable text stretching only changes that one setting. The BIOS setting doesn't enable the vertical stretching for graphic modes. Its video chip also can't do horizontal stretch at all but that's not an issue on the 400CDT since it's 640x480. More detail here: Re: The quest for the perfect retro laptop: a saga
You can override that behaviour with this utility: Re: The quest for the perfect retro laptop: a saga

Yep, those are both the LTM10C021 LCD panels 😀

My father didnt check it yet. Do you think this lcd panel for 400cdt or t2150cdt can be repaired ? The one with the lower part of the screen all white.( its from a 400cdt ltm10C021 "P02"
( i exchanged the fluorescent lamp with a good one and i exchanged the inverter with a good one. and it does not change anything )

I have another same model panel that backlight is dim its ltm10C021 "P01" from a t2150cdt. i tried the same thing, i changed the fluorescent lamp with a good one and i exchanged the inverter with a good one and it does not change anything too. not a slim difference, still dim

by the way i dont know the difference between
ltm10C021 "P01" and "P02" ( its the end of the other number written on the panel )

Thanks for advice or help. I will ask my father tomorrow to check the one that miss the bottom part of the screen that is all white.

I keep my best LCD screen model ltm10C021 "P02" in my Pentium 100mhz 420cdt. On the 420cdt the panel backlight is a little bit stronger and colors are more colorful and vivid than when this panel was installed on the 400cdt or t2150cdt, i tested both. its really a little better on the 420cdt ( i think because the videocard is better )

Huh, interesting point about the colour rendition on the 420CDT versus the 400CDT, the newer chip probably has better FRC / dithering than the 400CDT's video chip 😀

I have no idea what the P01 or P02 mean, sorry. Probably just minor production improvements or to signify that it's for a different laptop model. It did get used on the T4900CT, T2150CDS/CDT and the 400CDT so they probably used the VF0131P02 code for the 400CDT. The fact that you see a difference in brightness does suggest to me that perhaps they changed how the backlight section is made, with improvements to the fresnel sheets or acrylic. Or maybe the LCD itself is different and the later screen's transistors are more transmissive of light. Earlier TFT LCDs like the ones on the T4400SXC for instance need huge backlights with dual lamps and they're still pretty dim, later TFTs made big improvements there.

The bottom row driver failing to work on the LTM10C021 seems to be a common fault and a design flaw, with the damage probably resulting from a drop or knock where the LCD glass moved but the row driver board is screwed down so it didn't move, resulting in broken traces to the last row driver.

Check this out, I got an LTM10C021 LCD in that looked like this:

The attachment LTM10C021-repair (1) (Custom).JPG is no longer available

Reconnecting the connectors on the back made it look like this instead, same as your one now:

The attachment LTM10C021-repair (2).JPG is no longer available

The attachment LTM10C021-repair (3).JPG is no longer available

Taking the panel apart, I found that all the traces for the bottom row driver or CoF (chip on film) were severed, zoom in and you can see that the first and last set of six pins go nowhere. In this pic I first of all cleaned off the broken parts of the traces and cleaned the flux. Then put fresh solder onto what was left of the CoF's traces and put some fresh flux & solder on there. It was enough to connect up the middle 17 pins and reconnect the CoF to the LCD's row driver PCB:

The attachment ltm10c021-bottom-row-driver-repair.jpg is no longer available

Now it looks like this, just one broken line when displaying green which is pretty usable still:

The attachment LTM10C021-repair (4) (Custom).JPG is no longer available

Your LCD looks to be in better shape than mine was so it probably won't have any vertical stripes 😀

We got the screen to work perfectly, thanks to you

Now we will try to get the other lcd screen brighter.

( We have to build a ac adapter for a Samsung Note Master Laptop Model 386S/25e )