3Com 3C509B-C

The 3Com logo (big), "EtherLink III", "(C) 1994    3C509B-", "ALL RIGHTS RESERVED", "ASSY 03-0021-" "REV-", "FCC ID: DF63C509B", amd "10Mbps Signalling Rate" is silkscreened on top of the card.
 * "FAB: 02-0021-001 REV A" and "[3095] PCBC FR4"... is etched onto the bottom layer of the card.
 * The Ethernet controller is labeled with...
 * Parallel Tasking
 * 3Com
 * 40-0130-002
 * 9520S 22302553
 * AT&T 40-01302