EXHIBIT 4.3 FIRST SUPPLEMENTAL INDENTURE FIRST SUPPLEMENTAL INDENTURE dated as of March 25, 2003 (this "SUPPLEMENTAL INDENTURE"), among Comcast Corporation, a Delaware corporation (excluding its Subsidiaries, the "COMPANY" or "COMCAST"), Comcast Cable...Supplemental Indenture • March 26th, 2003 • Comcast Cable Communications Inc • Cable & other pay television services • New York
