do desktops PCs have 4 pin firewire ports??

Question

or is there anything such as a 6 pin to 6 pin firewire cable?

Answer 1

no fire wire extension pci cards are 6 pin
yes there is a 6 to 6 fire wire cable

do a web search for

6 pin to 6 pin fire wire cables

check the link below for fire wire cables