Here are my experiences with a 3CXFE575BT in a ACER 332T with SuSE 6.3 (Kernel 2.2.13, PCMCIA Card Service 3.1.3 with options: [pci] [cardbus] [pnp]: At first it is absolutely necessary to set PCIC_OPTS pci_int=1 Without this, there is a irq problem (I think so), because pinging to the gateway hangs up linux (pinging localhost and local-ip is o.k.) I did not test if PCIC_OPTS pci_csc=1 is necessary. At second I had troubles with the autonegotiation: FTP startet on another host with a 3c905B Cyclone 100baseTx, connecting to the 3CXFE575BT on the ACER 332T and making a "get" was with full speed, but making a "put" was very, very slowly (on the ACER I had RX packets errors). I had the same errors when I started FTP on the ACER (TX o.k. RX errors). (The connection between 3CXFE575BT on the ACER 332T under Windows98 and the host with the 3c905B Cyclone 100baseTx under Linux was o.k.) So I tried in a next step the mii-diag from Donald Becker: mii-diag on the host with the 3c905B Cyclone 100baseTx shows: Basic registers of MII PHY #24: 3000 786d 0000 0000 01e1 40a1 0007 2801. Basic mode control register 0x3000: Auto-negotiation enabled. You have link beat, and everything is working OK. Your link partner advertised 40a1: 100baseTx 10baseT. mii-diag on the ACER 332T with the 3CXFE575BT shows: Basic registers of MII PHY #0: 3000 282d 0300 e54b 00a1 41e1 0001 0000. Basic mode control register 0x3000: Auto-negotiation enabled. You have link beat, and everything is working OK. Your link partner advertised 41e1: 100baseTx-FD 100baseTx 10baseT-FD 10baseT. With mii-diag -F 100baseTx-FD on the ACER 332T I forced the 3CXFE575BT to go to 100 mbs half-duplex mode: Setting the speed to "fixed", Control register 2100. Basic registers of MII PHY #0: 2000 280d 0300 e54b 00a1 0000 0000 0000. Basic mode control register 0x2000: Auto-negotiation disabled, with Speed fixed at 100 mbps, half-duplex. You have link beat, and everything is working OK. Link partner information information is not exchanged when in fixed speed mode. That's it - hope that help people who are working with the 3CXFE575BT on a Linux-Notebook. Many thank's to David Hinds and Ronald Becker for doing all the work on PCMCIA and Ehternet.