You did not state what OS is on the P166.
If it's Win98 then you can add a USB PCI card to it and use a USB cable to transfer the data.
See this link:
Alternatively install an Ethernet card in the P166 and use a HUB or Switch to link/network the two PCs to transfer the files.
I have an old PCI Pentium, 166MHz MMX System, 512K
with 16MB EDO RAM, a Western Digital EIDE HDD. On-
Board PCI HD/FD Controllers w/Hi-Speed I/O & Para-
llel Ports in a Medium Tower. Also has a Genoa
PCI S3 SVGA Adapter w/ 2MB, an ESS 16-bit Sound
Card. I added an additional 8. plus Western
I would like to know if there's a cable connection
or an add-on adapter to connect the above PC with
my current AMD ATHLON XP System and be able to use
the above PC as a backup. My current system has
USB connections only. Any recommendations or ad-
vice would be greatly appreciated.