Hardware

I have a drawer full of spare AA and AAA batteries. Some are fresh, some are from remote controls that died last winter, some I found in a toy. Before tossing them or putting them to use, I check the voltage with a multimeter. It takes thirty seconds and saves you from guessing. What you need A cheap multimeter is all you need. Any digital one will do — I’ve used the same £8 model from Amazon for years. The probes should be intact and the battery in the multimeter itself should have charge (if it beeps when you turn it on, you’re good). ...

The quickest way to get a BIOS serial number on Linux: sudo dmidecode -s system-serial-number That’s usually all you need. dmidecode reads the DMI/SMBIOS table and prints the serial number directly. Other options If dmidecode isn’t available or doesn’t return what you need: # lshw sudo lshw -C bios | grep serial # /sys class interface (no sudo needed) cat /sys/class/dmi/id/product_serial The /sys/class/dmi/id/ path is the cleanest option if you want to avoid sudo. It exposes several DMI fields: ...