Hi again,

This is a last warning. If you are continuing to not quote previous mails, I'll
never reply to a posting from you again. Learn some netiquette!

On Fri, 2017-12-01 at 10:46 +0100, Edward Bartolo wrote:
> These are the results.

For what? With udev installed (which eudev version are you comparing with, now
asked twice) or eudev?

> The first listing lists only two files while
> the second lists all files.
>
> edbarx@edbarx-pc3:~$ find /lib/udev/rules.d/ -name '*usb*'
> /lib/udev/rules.d/39-usbmuxd.rules
> /lib/udev/rules.d/73-usb-net-by-mac.rules

Looking further to the *usb* files on my box shows:
(I had to go back to my reply to you to compare the lists, see above!!!)

dpkg -S /lib/udev/rules.d/*usb*
usbmuxd: /lib/udev/rules.d/39-usbmuxd.rules
usb-modeswitch-data: /lib/udev/rules.d/40-usb_modeswitch.rules
eudev: /lib/udev/rules.d/73-usb-net-by-mac.rules
modemmanager: /lib/udev/rules.d/77-mm-usb-device-blacklist.rules
modemmanager: /lib/udev/rules.d/77-mm-usb-serial-adapters-greylist.rules

They are probably not related to you problems.

> edbarx@edbarx-pc3:~$ find /lib/udev/hwdb.d/ -name '*usb*'
> /lib/udev/hwdb.d/20-usb-classes.hwdb
> /lib/udev/hwdb.d/20-usb-vendor-model.hwdb

Same result then, both are from eudev.

> Plugging in a USB thumbdrive, a new device name sdb1 was listed
> automatically under /dev. Using this with mount as root I could browse
> the contents of the USB thumbdrive in a terminal using cd and ls.
>
> I also cannot mount camera memory cards. Maybe this issue is due to
> the fact that the hardware was not recognised by the kernel.

Again, you have to compare with the files with systemd-udev installed. (Or
search in the *.deb files)