I've asked this elsewhere without getting a reply that works. I'm using a combination of cvt and xrandr as the basis of a script which adds the mode 1360x768_60.00 to the available options in Control Centre -> Monitor:
I've set this up as a desktop icon and can run it inside a terminal. It works fine. A look in Control Centre -> Monitor confirms the change of resolution. Trying to set this as Default, however results in a a hiatus at the next boot and the OS reverts to 1920x1080. The monitor is a Benq 22.5in and the AGP card is a Radeon X800GT.


I wanted to make the change permanent so I guessed that I needed to enter the file to run somewhere in the boot sequence or to insert the nitty-gritty of the code into something that does run in the boot sequence. It was suggested that the place to insert the code was /etc/mdm/Init/Defaults. Unfortunately that does not work. I suspect that, even if that code does run, it is overwritten by some other file.
As an aside, the system looks nice but it is a PITA to make any adjustments. It seems to be a waste to have GUIs all over the show, which cannot be used and the superuser has to resort to command line manipulation.
I would be grateful for any advice or suggestions to get this done.

As you have discovered, xrandr changes to resolution only last to the next reboot. To make changes permanent, you need to add them to your xorg.conf file.

You need to look at your LinuxMint documentation to learn how to do edit the file, or create it if it doesn't exist.

most distros have a gui for managing startup applications, so you could make this into an executable shell script and tell mint to execute it every login.
would that be sufficient?
it's certainly safer than creating and editing xorg.conf.

@ondoho Thanks for the reply. There was no xorg.conf in /etc/X11. I created one using a puppy lunux one as a template. Unfortunately, the video driver for puppy does not have the same name as the one that Mint uses (Mint's driver is clearly a lot better). It just ignores xorg.conf on boot-up. Is there a way in linux to get at the name of the driver used?
I still haven't found a way of inserting the script into the boot train.I tried putting in init.d and running update-rc.d. That didn't work - it went back to its default of 1920x1080.

my point precisely.

why don't you try adding the script to your desktop sessions autostart (no root privileges involved)?
i know it's technically not permanent, but at least it gets applied automatically.

Yes. I think that's going to be the best solution. Thanks for the input - I'll mark this as "Solved"