Falcosoft wrote on Today, 06:21:

At least on the T430 an external monitor (even through a digital connection) behaves completely differently to the internal LCD. Unlike in case of NVIDIA cards video modes are NOT projected to the native panel size of the external monitor. This is obvious right from the beginning since e.g.normal text modes are projected to 640x480 fixed resolution that makes text modes especially ugly on Intel HD graphics through a digital connection.
Currently ASPECT's logic relies on the inner LCD behavior.

Yes, this I suspected, and of course it did not correct on the Sandy Bridge desktop. (This is connected via HDMI cable to external display). It is irrelevant like you said since the logic of that external monitor "corrects" 720x400 or 320x200 or 320x240 to 640x480. The external monitor does its own upscaling, which is poor, but does respect 4:3 ratio on 16:9 display. by windowboxing 4:3 content.

It is therefore understood that ASPECT.COM is intended only for internal laptop displays.

zyzzle wrote on Yesterday, 20:49:

For intel 945GM onboard graphics, you may try the attached INTEL.EXE file. I compiled this over 15 years ago and it works on my Intel Atom netbook (Asus with 1.6 Mhz Intel Atom 230 CPU). This file will change aspect ratio to 4:3 in graphics modes (VESA, VGA), but not in text mode. It consumes a lot of low DOS memory, though. Try it and report if it worked on your system.

Many thanks!

Tested, but it doesn't work in my system.

After running INTEL.EXE the screen powers off, after a couple of seconds powers on, there is a brief flash (maximum brightneess) and the screen goes blank (screen powered on) with no image.
I was able to run MEM and output to a file. Before loading INTEL, conventional memory was 621K after loading was 486K.

According HWiNFO, your GPU is an 82945GME and mine is an 82945GM. My screen resolution is 1366x768. Could be these differences the problem?

keenmaster486 wrote on Yesterday, 19:48:

... Is there a way to control which scaling algorithm is used? (bilinear, nearest neighbor, etc.)

I was right that there are no multiple usable scaling mode presets but I was wrong about what is the default: It's not bilinear but a medium 3×3 filter (so somewhat better than a regular 2x2 bilinear).
Also in case of Ivy Bridge there are 2 modifier bits: edge-enhancing and edge-softening. Interestingly both results in a softer/more blurry and less pleasant image quality overall 🙁
But it seems there is a 3rd way, namely a custom programmed filter mode with custom coefficients. Maybe it's possible to achieve something sharper that resembles nearest neighbor. Investigation is in progress...

@Edit:
So far it is a dead end. All available sources and driver programs including Linux drivers do not program custom Ivy Bridge coefficient tables but simply force Medium 3x3 instead...
There are no examples how the custom coefficients should be programmed.

@Edit2
Finally an Intel document has been found and it seems we can get a much sharper filter than the default one.

New version of ASPECT/ASPECTD has been made.

/AS parameter added ( as Aspect corrected Sharper). This is also a real-time parameter so can be used when ASPECT/ASPECTD is loaded. Here are some test images:

Normal aspect ratio corrected (/A)

Sharp aspect ratio corrected (/AS)

AFAIK this feature is not available either in the Windows or Linux drives 😀

Thinkpad X201: 1066x768 107,0
Thinkpad T430 (upgraded to 1080p panel): 1440x1080 240,0
Thinkpad X1 Extreme: will not boot from floppy due to lack of legacy BIOS support.

The "sharp" option does not work on the X201.

On the T430 it looks very sharp, but it is clear that it is not a filter at all, but just nearest neighbor scaling, so the pixel sizes are not consistent. It might look better on a 1440p or 4K panel. I wonder if there is a way to get something in between, something more akin to the "sharp" glshader option in DOSBox Staging.