Along about 2010 Firewire was beginning to be abandoned in favor of USB and faster alternatives in laptops. However there was still a good use for Firewire or IEEE1384 ports for connecting legacy hard drives, cameras and video capture equipment.
For a time laptops could still be found with Expresscard ports and used with Expresscard to Firewire / IEEE1384 ports but eventually those went away as well.
Sony Vaios, Lenovos, Dell and HP products initally had some laptops with "mini" IEEE1384 ports but they too disappeared.
Apple Macbook Pros eased the transition by including a Firewire 800 port and a Display port, and then replaced the Display port with the identical port on Macbook Retinas with a Thunderbolt 1.0 port.
It wasn't called Thunderbolt 1.0 but retroactively can now be referred to as Thunderbolt 1.0 since there were Thunderbolt 2.0 and Thunderbolt 3.0 versions later.
Thunderbolt 1.0 is basically a Display port connector with additional lines to support PCIexpress connections in the same connector as the original mini Display port connector.
Thunderbolt 2.0 is essentially the same as Thunderbolt 1.0 using the same mini Display port connector with a logical speed boost from 10 Gbps to 20 Gbps.
Thunderbolt 3.0 uses a different connector (USB-C) and also supports a USB 3.0 mode as well as getting a speed boost to 40 Gbps.
Besides Apple, a few manufacturers also made early laptops with Thunderbolt 1.0 connectors. HP being one with the Spectre XT 15 Ultrabook line. These had one mini Display port Thunderbolt 1.0 connector.
Designed for Windows 8 (and later upgradeable to 8.1 and 10) out of the box, they would only support Thunderbolt 1.0 devices certified for the Windows OS.. and would not support The Apple Firewire to Thunderbolt adapter.
However HP retroactively released a Thunderbolt 1.0 port configuration tool for their Thunderbolt firmware that could enable support "Any" Thunderbolt connected device whether it was certified with Windows or not. This enables Windows 8/8.1/10 to support the Apple Firewire to Thunderbolt 1.0/2.0 adapter.
Basically once this tool is run the Thunderbolt port is set to enable all Thunderbolt devices connected to its port. This is not the default because of the Intel specification barring support for certified devices for specific operating systems. Its rather nonsensical and unintuitive. Without doing this inserting the Apple Firewire to Thunderbolt adapter only adds six PCI to PCI bridge devices to the device manager tree and stops.. it does not enumerate the 1394 OCHI device on the other end of the adapter.
The HP Spectre XT 15 is based on the Intel IVY chip architecture which means it fully supports Windows 7 and has a Legacy CSM BIOS mode for booting from MBR partitions.. which means not only is Windows 7 x64 (64 bit mode) supported, but Windows 7 x86 (32 bit mode) is also supported.
Once the Thunderbolt port is configured "open" to support uncertified Thunderbolt connected devices.. this carries over if Windows 7 x64 is installed, even for Windows 7 x86.
What happens when the Apple Firewire to Thunderbolt adapter is inserted (hot swapped) into Windows 7 x86 (32 bit) is six PCI to PCI bridge devices are created attached to one of the PCI express root ports, off of one of those a 1394 OCHI device is enumerated, and then an AVC and AVC Tape device is created.. if you have a firewire video capture device like an ADVC Canopus video capture codec attached.
The default 1394 OHCI device driver is not best and should be swapped for the (Legacy) version for regular work.. but it works.. in 32 bit.
This is a pretty slick method of using a Thunderbolt port on a Windows PC to connect up a native Firewire device for video capture and feed that into many 32 Bit Non-Linear Editor workflows from the past.. like Sony Vegas, Adobe Premiere and so on.
This also worked for later HP Zbook and Folio Ultrabooks.. as long as you manually downloaded the HP tool for re-configuring the Thunderbolt port and opened it up.. for Thunderbolt 2.0 and Thunderbolt 3.0 later chip architectures however make it less compatible with older operating systems.
The HP Spectre XT 15 is a little unique in having the IVY chipset since in theory it can also support Windows XP .. a rare thing today.. if you need it. And it will be interesting to see if Thunderbolt 1.0 can be supported under XP in a native manner.. stay tuned.