This is normal, lucky you not having any horrible scaling, beside text, look terrible in your picture

AlessandroB wrote on 2025-10-15, 21:46:

I've never been in this situation before... what can I do? I looked at the BIOS and there doesn't seem to be anything wrong. It's a Texas Instruments Extensa 900T.

According to info I can find online, it's got a Chips 65550 video chip - so you should be able to fix your scaling to get full screen 320x200 with the VEXP.COM utility. Or this one perhaps: VSTR - utility to stretch the image on CT6555x based laptops with 800x600 & 1024x768 LCDs - testers needed!

Hey! I've never heard of it before, but it works! (pretty much, let's say) I don't know if there's a way to customize it more deeply because it fills the screen but distorts it quite a bit.

The distortion is due to the fact the panel is not an exact multiple of the game resolution. It's a limitation of all early laptops.

Once you had chips like the ATI Rage LT, Geforce and some later S3 they started to do filtered/interpolated upscaling of non-native video modes and it makes upscaled screens much nicer.

Newer laptops with nice scaling built in *and* native support for Dos sound are limited and/or harder to find, however. A better option these days can be to use VSBHDA to provide dos sound on more modern laptops with nicer screens/scaling.

Unfortunately, this is best you can do with this chipset, because the scaling is literally done just with replicating certain pixels horizontally and certain scanlines vertically. The only thing you can steer is the parameters that govern the degree of replication given different input / output resolution combinations.

xnplater wrote on 2025-10-17, 14:46:

Unfortunately, this is best you can do with this chipset, because the scaling is literally done just with replicating certain pixels horizontally and certain scanlines vertically. The only thing you can steer is the parameters that govern the degree of replication given different input / output resolution combinations.

how can i do that?

VEXP accepts a number of optional parameters, but they *mainly* affect how it scales text modes.

megatron-uk wrote on 2025-10-17, 19:43:

VEXP accepts a number of optional parameters, but they *mainly* affect how it scales text modes.

i see…. My IBM T20 doing a much better result in a DOS games, even if it is more modern and far from the DOS period

Another potential option is to use an external VGA monitor, either directly or, for even better results, through an OSSC or an external scaler.

Obviously, this isn't be practical or oven possible for everyone due to limits on space or the need for portability.

AlessandroB wrote on 2025-10-18, 14:56:

megatron-uk wrote on 2025-10-17, 19:43:

VEXP accepts a number of optional parameters, but they *mainly* affect how it scales text modes.

i see…. My IBM T20 doing a much better result in a DOS games, even if it is more modern and far from the DOS period

It's awkward, there's a limited window for laptop / display & audio hardware where DOS audio still worked and displays were able to scale well. Displays were too low resolution to do true integer scaling and display chips didn't yet do smooth scaling / non-integer scaling. The Chips 65550 is able to do scaling but it will result in some pixels being double width and others just single lines - fine for 320x200 but it looks awful with higher res like 640x480.

If it was a venn diagram, the area where the two circles overlap would be very small. The Toshiba Satellite 2805 stands out though I've found a couple of other interesting examples as well.
Simply connecting to an external display should resolve the issue for you though.

Having now used it extensively, I'm convinced a modern laptop with either VSBHDA (or SBEMU) is the better option for native DOS gaming.

The choices are much greater, theres a better chance of getting spares/replacement parts like batteries and they nearly all have built in screen mode upscaling interpolation that leaves early laptops looking archaic.

The Toshiba 2805 is a good example of one with native (Yamaha) sound, and nice scaling if you get the Geforce powered model, but if you are prepared to use the dos audio emulator solutions (the aforementioned VSBHDA and SBEMU) even an Intel GMA based video will do interpolated full screen scaling.

Of course with later laptops you run the opposite problem of finding screens that are still 5:4 or 4:3 aspect ratio. From late P-M and P4-M they became the standard.

Ironically business class machines (ThinkPad, Latitude etc) become great options when you introduce the sound emulators and they retained traditional screen aspect ratios longer than consumer models did.

AlessandroB wrote on 2025-10-17, 18:05:

xnplater wrote on 2025-10-17, 14:46:

Unfortunately, this is best you can do with this chipset, because the scaling is literally done just with replicating certain pixels horizontally and certain scanlines vertically. The only thing you can steer is the parameters that govern the degree of replication given different input / output resolution combinations.

how can i do that?

You can use VEXP 1.3 and use 'VEXP.COM M2', this should work best. Or you can try my experimental VSTR utility as 'VSTR /P:800 /ON', but the result should be the same.