I recently purchased an Acer AL1916W, a nice Widescreen TFT with an unusual resolution of 1440×900 px, which was at first a challenge to configure. I tried various setups in xorg.conf, en- and disabled DDC, even wrote my own modelines. The best I got was an 1440×900 resolution with black broders (~ 3 cm) on the left and right.
Until i read the manual (RTFM!), which I couldn’t find at the Acer Worldwide Homepage, so i provide it here: Acer AL1916W Handbook. At the end of the manual the reference signalmodes are listed:
Display Mode: WXGA 1440×900
Horizontal Frequency (kHz): 55.935
Vertical Frequency (Hz): 55.887
Pixel Frequency (MHz): 106.5
SYNC Polarity (H/V): -/+
At first i was puzzeld, because the refreshrate isn’t an integer (as I thought it should be). Nevertheless I used gtf, a small xorg-tool to calculate VESA Modlines, with this values:
~ # gtf 1440 900 55.887# 1440x900 @ 55.89 Hz (GTF) hsync: 51.97 kHz; pclk: 98.96 MHz
Modeline "1440x900_55.89" 98.96 1440 1520 1672 1904 900 901 904 930 -HSync +Vsync
Using this ModeLine in xorg.conf, the Acer detects a 60 Hz refresh rate, and the auto-adjust works fine, the borders are gone.
Dear Carlo,Thanks a lot for your rposense. I am using a server, no laptop. I used the word “default” before connected as the name and it work well. I could define the new mode. Now appear between the options of monitor preferences (at system/preferences/monitor) However when I try to use it, the message “the selected configuration for displays could not be applied, could not set the configuration for CRTC 262″. I can not fix the problem yet. I thanks in advance if you have other suggestion.P.
Cold you show us your xorg.conf config please? thanks
Ok, this worked for me! here is my xorg.conf for fedora 19.
Section “Monitor”
Identifier “VGA-1”
Modeline “1440x900_55.89” 98.96 1440 1520 1672 1904 900
901 904 930 -HSync +Vsync
Option “PreferredMode” “1440x900_60.00”
EndSection