The process to change Debian repository choices is (from my recall) identical to that deployed with Devuan. I think that his problem lies elsewhere, rolfie.

@boughtonp:
Thanks for rclone notice (yup, supports Dropbox natively). Looks like the kind of option I was looking for. Have downloaded & will be using it in anger soonish, soon as I get to grips with help.

Added Fri 19:
This morning I spotted a tit (small bird, not certain of specie) jumping around the branches of the large Cherry tree outside my bedroom window. Yesterday my near neighbour informed me that he had spotted blackbirds eating apples fallen onto a garden shed not visible from my windows. So, the future for the acre + birdsong looks more hopeful than I had previously thought.

Those birds all manage to fly across the Channel, so I guess that they should be tough enough to survive a few cold nights.

You are sounding a bit whiny there, Steve.

It's not a question of whose time is more valuable. The Court expects participants to use Dropbox - my first use, and not my decision. I thought that it may also be useful for others if Devuan becomes an option in addition to Debian & Ubuntu. I would love to get involved, and also in lots of other things as well. I just cannot, so put it out there. It's not a demand. It is a request (oh! horror!).

Well, with 80 views in 24 hours that is, of course, a near certainty (if this not obviously irony, then consider that I am a mod at SFS and in mid-December the Stats Page reported 2m queries daily; now that gets close to a DDOS).

Thanks for the Berlios link. Reviewing my dmesg output I spotted that it was a UVC camera (have never come across that before):

[481614.064887] usb 1-1.3: Found UVC 1.00 device USB 2.0 Camera (1bcf:2cc9)

An API is not a driver.

In my reading I notice many mentions of laptops with builtin webcams. If one of those is supplied with Linux (unlikely, I would have thought) then it would come with a driver that would utilise the V4L API. Otherwise not.

The main problem with cheap devices for Linux is not the driver but the way that so much (so-called) hardware-processing is actually off-loaded to the local CPU rather than handled by the hardware. That is the reason for so much "non-free firmware" in the apt sources.list. The dirty secret that is not mentioned there is that this is actually 'non-free firmware-originally-designed-for-Windows'.

You can see some of what I'm talking about in this PDF about modems & DSPs ("Digital Signal Processing"). On Page 9.3 it states:

(DSPs are also used in sound processing)

The point of that paragraph is that DSP's are supposed to be specialised hardware chips contained within the modem. But no - that is too expensive. So instead the modem contains a cheap EEPROM which loads external firmware, and that causes the modem to use the local laptop cpu to run the DSP algorithms. Now, in the 1990s when this was all first originated there was ONLY Windows firmware, and Linux & Mac & all other OS had to go hang themselves. Now, after 25 years, we do actually have some firmware grudgingly provided (but no code, so it is non-free). Also, all updates arrive at Windows first.

But, it seems that my web-cam actually contains all necessary hardware. Hooray!

Note #1:
Both the Amazon product link + img link in post#1 come from my browser history in buying this product. Please report if either fails for you so that I can search out generic links to replace them.

Note #2:
The gov.uk CVP page should be available for non-UK visitors. I'm less certain whether the try-it-out-live page linked on that page will work for non-UK folks. Do drop a post here stating whether either worked for you.

Note #3:
I came across Guvcview, which is a useful UVC-based utility to check a webcam which also has snapshot/record video buttons. It is available in the repository:

$ apt search Guvcview
Sorting... Done
Full Text Search... Done
guvcview/stable,now 2.0.8-2 amd64 [installed]
  GTK+ base UVC Viewer

libguvcview-2.1-2/stable,now 2.0.8-2 amd64 [installed,automatic]
  GTK+ base UVC Viewer - runtime

libguvcview-dev/stable 2.0.8-2 amd64
  GTK+ base UVC Viewer - development files

I like boughtonp's 2nd one better. For some reason "adult" reads sour in my eyes. Perhaps it's because of terms such as "adult films".

Your sources differ slightly from what is advised (missing non-free). I have zero idea how important that may be, but for the record (and thanks for the inxi snippet):

$ head -5 /etc/apt/sources.list
deb http://deb.devuan.org/merged daedalus                  main non-free-firmware non-free contrib
deb http://deb.devuan.org/merged daedalus-updates          main non-free-firmware non-free contrib
deb http://deb.devuan.org/merged daedalus-security         main non-free-firmware non-free contrib
deb http://deb.devuan.org/merged daedalus-proposed-updates main non-free-firmware non-free contrib
deb http://deb.devuan.org/merged daedalus-backports        main non-free-firmware non-free contrib

If you are *really* paranoid, don't try this one:

$ grep ^[^#] /etc/apt/sources.list /etc/apt/sources.list.d/*
/etc/apt/sources.list:deb http://deb.devuan.org/merged daedalus                  main non-free-firmware non-free contrib
/etc/apt/sources.list:deb http://deb.devuan.org/merged daedalus-updates          main non-free-firmware non-free contrib
/etc/apt/sources.list:deb http://deb.devuan.org/merged daedalus-security         main non-free-firmware non-free contrib
/etc/apt/sources.list:deb http://deb.devuan.org/merged daedalus-proposed-updates main non-free-firmware non-free contrib
/etc/apt/sources.list:deb http://deb.devuan.org/merged daedalus-backports        main non-free-firmware non-free contrib
/etc/apt/sources.list.d/josm.list:deb https://josm.openstreetmap.de/apt/ alldist universe

Here's an alternative information gatherer; also operated from a terminal; show results from one of these & others will understand better your system & be able to give better help & advice:

$ inxi -b
System:
  Host: ng3 Kernel: 6.1.0-17-amd64 arch: x86_64 bits: 64 Desktop: Xfce
    v: 4.18.1 Distro: Devuan GNU/Linux 5 (daedalus)
Machine:
  Type: Desktop System: LENOVO product: 90BJ008CUK v: Lenovo H30-05
    serial: <superuser required>
  Mobo: LENOVO model: N/A v: SDK0J40700 WIN serial: <superuser required>
    UEFI: LENOVO v: O1WKT25AUS date: 10/29/2015
CPU:
  Info: quad core AMD A8-7410 APU with AMD Radeon R5 Graphics [MCP]
    speed (MHz): avg: 999 min/max: 1000/2200
Graphics:
  Device-1: AMD Mullins [Radeon R4/R5 Graphics] driver: radeon v: kernel
  Display: x11 server: X.Org v: 1.21.1.7 driver: X: loaded: radeon
    unloaded: fbdev,modesetting,vesa dri: radeonsi gpu: radeon
    resolution: 1366x768~60Hz
  API: OpenGL v: 4.5 Mesa 22.3.6 renderer: KABINI ( LLVM 15.0.6 DRM 2.50
    6.1.0-17-amd64)
Network:
  Device-1: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter
    driver: ath9k
  Device-2: Realtek RTL810xE PCI Express Fast Ethernet driver: r8169
Drives:
  Local Storage: total: 931.51 GiB used: 785.39 GiB (84.3%)
Info:
  Processes: 200 Uptime: 3d 13h 58m Memory: 7.18 GiB used: 2.89 GiB (40.2%)
  Shell: Bash inxi: 3.3.26

What's wrong with 7z ('7-Zip') (Website / Wiki)? Teeny tiny and with the best compression on the 'net. Downside is that it does not do any encryption, nor even store Linux file attributes. What you have to do is store as "file.tar.7z" (like gzip, but a separate tar operation, then 7-zip it). Y'know, small apps that each do one thing, chained together. The Linux way.