Does Setup actually use HGC?

[Cigaryno]

The way the text-mode portion of Setup starts has changed in Windows NT 3.5 and stayed until Windows XP. When it starts and reaches the welcome screen, it switches to 720x348 which is exactly the GUI mode resolution of the Hercules Graphics Card. Do you think Setup actually uses the Hercules Graphics Card or a forgotten mode of the VGA card for backward compability with the HGC?

[dixieLH]

most likely something generic (call it what you will)
just the same thing as if you enter in safe mode

[AlphaBeta]

No, because VGA is not actually backwards compatible with Hercules like, at all.

[vbdasc]

No, because VGA is not actually backwards compatible with Hercules like, at all.

Exactly, this, plus VGA doesn't have a video mode like 720x348. VGA standard text modes use 720x400, and maybe 720x350 if using the 8x14 BIOS font, but not 720x348.

[Hyoenmadan86]

The way the text-mode portion of Setup starts has changed in Windows NT 3.5 and stayed until Windows XP.

This was done for compatibility and experience uniformity with ARC NT RISC platforms. This also avoids code duplicity on setup display routines with it.

Resolution in setup mode is determined by your display adapter, as it uses the display driver to do it (no, it doesn't use the BIOS, not directly at least). On RISC platforms, it will be generally be set up equal to the firmware framebuffer resolution (like will be done in UEFI many years in future btw) . On PCs, it will be set up to some standard minimal VGA resolution as long as there is a VGA compatible adapter in the system, but there are some exceptions for a few (old) cards.

Finally, if I remember well, Setup already uses graphics modes to display its "text" output, not text modes. Unfortunately in this except, it works very differently from ReactOS setup, so your only reliable information source on this, if you are interested in the details, would be any of the leaked sources.