A while ago, I wrote about us­ing a cheap 1080p TV as ex­ter­nal mon­i­tor on Ubun­tu. That hap­pens to cause some weird prob­lems be­cause the TV is try­ing to be smart about clip­ping things, etc (just read it if you wan­t.)

In it I out­lined a bunch of ap­proach­es that suc­ceed in fix­ing over­scan with dif­fer­ent lev­els of suc­cess. Here's some ex­tra de­tail for one of those, set­ting up a cus­tom mode which does­n't trig­ger over­scan:

First, go to http://www.arach­noid.­com/­mod­e­li­nes/ and cre­ate a mod­e­line for some mode that is close to 1080p but not quite there. How close to 1080p you can get be­fore your TV de­cides "this is 1080p I am do­ing over­scan" will vary.

For ex­am­ple, I can do 1800x1012 with this mod­e­line and can prob­a­bly do a bit more:

Modeline "1800x1012_60.00" 151.42 1800 1912 2104 2408 1012 1013 1016 1048 -HSync +Vsync

Then, to ex­per­i­men­t, we can add this mode to X us­ing xran­dr. Here HD­MI1 is the out­put I have con­nect­ed to my TV:

xrandr --newmode "1800x1012_60.00" 151.42 1800 1912 2104 2408 1012 1013 1016 1048 -HSync +Vsync
xrandr --addmode HDMI1 "1800x1012_60.00"
xrandr --output HDMI1 --mode "1800x1012_60.00"

I don't think it works as well as the force-d­vi hack from the last time, but hey, I do get HD­MI au­dio, and I have not seen this de­scribed else­where us­ing xran­dr.