GSC is a bus used in many of the HP 9000 workstations and servers.
The 715/Mirage, 725, 735, 755, B-, C-, and J-class workstations, and the D- and R-class servers, used the so-called "EISA form factor".
Many different types of card were produced, including Gigabit Ethernet, single and dual 100 Mbit Ethernet, Ultra-2 SCSI, ATM and graphics.
The K- and T-class servers both used the "3x5" form factor, although the different brackets prevent the cards being interchangeable.
Fibre channel and Gigabit Ethernet cards both exist.