First post, by clb
Before VESA came along, different video hardware vendors adopted all kinds of different custom video modes.
I found http://www.columbia.edu/~em36/wpdos/videomodes.txt that lists many of these modes.
I am looking to explore this space a bit more for programming these modes from real mode programs.
The main thing I am curious is: how common were video cards that had custom modes, but did not yet support VESA VBE 1.0, 1.1 or 1.2? Or did software like UniVBE practically encompass all the display cards by adding software wrapped support for all of these custom not-yet-VESA-standardized modes that each adapter had?
For example, if I look at the above list and the mode
58h = G 100x37 8x16 800x600 16/256K . A000 Cirrus CL-GD5420/5422/5426
on my Cirrus Logic GC-5422 video card, I understand that is *not* a VESA VBE video mode. But is initializing that video mode identical to having used VESA VBE 1.x services to initialize the video mode? (and that's what the UniVBE driver ends up doing anyways?)
Also I am curious if people know about different pre-VESA display adapter programming manuals, e.g.
- scanned programming manuals of different video hardware vendors that would "officially" list their expansions to the CGA/EGA/VGA modes,
- official resources from vendors on how the presence of their VGA display adapter should be identified?
- unofficial ways to identify different graphics cards (parse strings or magic ID addresses from VGA BIOS memory? run some vendor-specific custom IO port writes/reads?)
Thanks!