black link and graylink are commonly named "Graph link". Black link and gray link are composed by a jack on calc side and serial port on computer side.
I recommend using the silver link (jack/usb) instead of this old link.
These links are of course compliant with ticonnect and tilp.
So having gray link or black link is OK to transfer programs to your calc (or even backup your calc) with ticonnect or tilp.
