After I posted the sysinfo of Dell-790 machine, I intended to
make another 0x29a2 did old machine work, and then post
the results.

However, I got much tired, and can't do anything now.
It may continue one month or so.
Therefore, I'll post the diff to the last cdrom for Dell790 sandy-bridge machine
to work up to 1680x1050x32 resolution, not work for DP/HDMI, though.
This patch includes the one posted by cinap before.

It was made by the command:
diff -n /sys/src/cmd/aux/vga/igfx.c /n/cdrom/sys/src/cmd/aux/vga/igfx.c.

Kenji