From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <ffbe61b259ef8d6a9c206e780a3fe058@krabbe.dyndns.org>
To: <9fans@9fans.net>
Date: Wed, 16 Apr 2014 11:39:05 +0200
From: Ingo Krabbe <ikrabbe.ask@gmail.com>
In-Reply-To: <5e318d6638d33dad5d52790043cf25c7@pi.att>
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Subject: Re: [9fans] (no subject)
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>>> In my experience a VESA BIOS will sometimes report
>>> different available modes depending on the detected
>>> EDID.
>>
>> I have no problem believing this is true, but I'm also sure > there's more to it than that.
>
> I agree. One problem is that these things are all different,
> almost completely undocumented, and implement non-standard
> modes seemingly at random. Some people involved with various
> OSX86[0] efforts have developed methods for probing (and in
> some cases, modifiying) the VESA BIOS on some cards. All
> kinds of strange behaviors have been observed.
>

In qemu the emulated controller seems to support 1920x1200x{16,24,32} as well as some other modes

term% aux/vga -m vesa -p
warning: reading edid: VBE error 0x0100
vesa flag            Ulinear|Hlinear
vesa sig            VESA 2.0
vesa oem            Bochs/Plex86 VBE(C) 2003 http://savannah.nongnu.org/projects/vgabios/ 0.2
vesa vendor         Bochs/Plex86 Developers
vesa product        Bochs/Plex86 VBE Adapter
vesa rev            $Id: vbe.c,v 1.64 2011/07/19 18:25:05 vruppert Exp $
vesa cap             8-bit-dac
vesa mem            16777216
[...]
vesa mode           0x187 1920x1200x16 r5g6b5 direct
vesa mode           0x188 1920x1200x24 r8g8b8 direct
vesa mode           0x189 1920x1200x32 x8r8g8b8 direct
vesa mode           0x18a 2560x1600x16 r5g6b5 direct
vesa mode           0x18b 2560x1600x24 r8g8b8 direct
vesa mode           0x18c 2560x1600x32 x8r8g8b8 direct
[...]

you may be able to try these with your monitors as a start.

>> I'd be interested in a survey with broader results
>> than just dueling anecdotes
>
> I haven't made any attempt to catalogue VESA vs EDID
> discrepancies, but I do keep a small archive of hardware
> info here:
>
> http://plan9.stanleylieber.com/hardware
>
> We try to collect the sysinfo[1] output for as many
> systems as possible, for later reference.
>
> sl
>
> [0] http://www.osx86project.org
> [1] http://man.aiju.de/1/sysinfo