Jabber1's questions

I installed ubuntu on a dell xps laptop thinking everything would be compatible. It seemed to work fine after installation, except for the sound, and on that point, there are a number of problems.

Most importantly: microphone captures sound with such extreme distortion that no conversation is possible in webchat. Same distortion on video capture.

There are various other problems as well, but most important for the moment is finding some way to use a microphone without screeching distortion (even just to record a test-video in cheese, for example).

Specs:

Dell XPS 13 9305
Ubuntu 20.04.3 LTS
$ uname -srm
Linux 5.13.0-28-generic x86_64

$cat /proc/asound/card0/codec\*  | grep Codec
Codec: Realtek ALC3271
Codec: Intel Tigerlake HDMI

It sounds similar to this problem and this one.

If anybody has any ideas how to get the microphone working, I'd much appreciate any help you can offer. Thanks in advance.

To share a folder on my Local Area Network, I used these instructions, and just had to click the box saying "Share this folder". Great.

Then I changed my mind, so I thought in order to UNDO that, I just needed to un-tick the box. Nope. Because now that I've installed Samba, the box doesn't exist anymore. Instead of the "Local Network Share" tab, there are tabs for "Permissions", "Notes", "Access Control List", "Extended User attributes". A whole bunch of really complicated stuff, and nowhere is there any box to just say "DON'T share this folder anymore".

Theoretically, I could just change permissions, but that's missing the point. Somewhere, a setting has been saved that says "This is a folder I want to share". Where is it, and how do I undo that?

I have a Macbook from 2008 (Intel Core2 duo) running Ubuntu 20.04. The primary display (on the laptop screen) is fine, and I'm plugging the external monitor in through a DVI-mini display adapter. The 2nd display (external) comes through, but at the default resolution (1920x1080) is unstable. It's like watching old DVDs with bad compression or connection.

When making adjustments with "Displays", the whole system locks up whenever I click apply. I've rebooted and tried this again, and the same thing has happened about 4 times now. Everytime I try to change anything in Displays with the external plugged in, the system locks up and I have to reboot. With just a the laptop monitor alone, I can make changes.

Seems like a bug with the "Displays" applet. Any suggestions would be welcome. Here is the output from xrandr:

$ xrandr
Screen 0: minimum 320 x 200, current 3200 x 1080, maximum 8192 x 8192
LVDS-1 connected primary 1280x800+1920+280 (normal left inverted right x axis y axis) 286mm x 179mm
   1280x800      60.22*+  59.99    59.97    59.81    59.91  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00    59.95  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    59.96    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94    59.94  
   720x405       59.51    58.99  
   720x400       59.97  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98    59.96  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   640x350       59.84  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
DP-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 298mm
   1920x1080     60.00*+  59.96    59.93  
   1680x1050     69.88    59.95    59.88  
   1600x1024     60.17  
   1400x1050     74.76    70.00    59.98  
   1600x900      59.95    60.00    59.82  
   1280x1024     75.02    60.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      75.00    75.00    70.00    60.00  
   1280x720      60.00    59.99    59.86    60.00    59.74  
   1024x768      75.05    60.04    75.03    70.07    60.00  
   960x720       75.00    60.00  
   928x696       75.00    60.05  
   896x672       75.05    60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   832x624       74.55  
   960x540       59.96    59.99    59.63    59.82  
   800x600       75.00    70.00    65.00    60.00    72.19    75.00    60.32    56.25  
   840x525       74.96    69.88    60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       74.76    70.06    59.98  
   800x450       59.95    59.82  
   640x512       75.02    60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    75.00    72.81    75.00    59.94  
   720x405       59.51    58.99  
   720x400       70.08  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       75.00    75.00    70.00    60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       75.03    70.07    60.00  
   512x288       60.00    59.92  
   416x312       74.66  
   480x270       59.63    59.82  
   400x300       72.19    75.12    60.32    56.34  
   432x243       59.92    59.57  
   320x240       72.81    75.00    60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  

I tried to set up dual-booting on my macbook mostly following these instructions.

Everything seemed fine, up to the very last step; when I rebooted the system (even if I held command-R) I didn't get any rEFInd boot menu or recovery mode, it just booted to Ubuntu with no way of recovering OSX.

The solution: install refind again.

sudo apt install refind

It will insist on installation to the right partition for EFI. Once it's done, just reboot (this made me nervous, but it worked out ok). Next boot you'll see the OSX and ubuntu options in the refind menu.