Note though, there have been many reports of people having difficulties getting them to work with Windows 10, as legacy support for IEEE1394 (which FireWire uses) is not installed by default. If you have a standard desktop PC, then you can add a FireWire PCIe card. An additional adapter (Thunderbolt 2 to Thunderbolt 3/USB-C) is needed if you have a newer Thunderbolt 3 Mac.
If you have a Mac with a Thunderbolt 2 port, then Apple sell a Thunderbolt 2 to FireWire 800 adapter for about $30. There are even some reports of them causing damage too. For example, check the reviews on this item and take heed.
Cheap USB to FireWire 'adapters' appear to be available, but I would not expect them to work in most cases. FireWire is not compatible with USB at a protocol level - they 'talk' to each other in different ways.
