Cut your screen resolution exactly in half!
Posted: 27 Dec 2021, 23:25
I remember those days of reconfiguring xorg.conf manually, restarting, and having my finger right on the power switch nervously awaiting smoke or snap/crackle/pop ! 
Not sure if this applies, but I looked back into my old Knoppix notes from Klaus, and saw that sometimes monitors can lie or be fooled by KVM switches and the like which might be preventing this half-res hack from working..
The special kernel cheatcode was used to allow for a higher vertical or horizontal rate - not to set it, but just to allow a higher range if the system deemed it necessary:
hsync=95
or for vertical, say vsync=75
Perhaps when we calculated the non-standard res using 60hz, the system wants something slightly higher and might be on a knife-edge? Those hsync kernel cheatcodes seemed to give the system some breathing room if it couldn't get it right.
BUT, this is just GUESSWORK on my part! I'd have to get some other combo of hardware to test it, since it works without this for me...
Not sure if this applies, but I looked back into my old Knoppix notes from Klaus, and saw that sometimes monitors can lie or be fooled by KVM switches and the like which might be preventing this half-res hack from working..
The special kernel cheatcode was used to allow for a higher vertical or horizontal rate - not to set it, but just to allow a higher range if the system deemed it necessary:
hsync=95
or for vertical, say vsync=75
Perhaps when we calculated the non-standard res using 60hz, the system wants something slightly higher and might be on a knife-edge? Those hsync kernel cheatcodes seemed to give the system some breathing room if it couldn't get it right.
BUT, this is just GUESSWORK on my part! I'd have to get some other combo of hardware to test it, since it works without this for me...