From The Apple Wiki
A gorilla cable
Bottom of gorilla cable

The Gorilla Cable is a JTAG/SWD Cable capable of debugging CPFM 00 or 01 devices which have the 30 pin port, using software called Astris. It can do JTAG/SWD and UART/Serial. They can be purchased from obscure markets. This cable has a tckrate of 976000.


Dumping the SecureROM

One use of the cable is dumping the SecureROM from devices. This can be done using commands such as this one.

Debugging the SOC

Astris, along with this cable can be used to debug devices and basically run anything on them as long as the device has a CPFM of 00 or 01, or atleast demoted to those values.