3Com 3c509

3Com 3c509 is a line of Ethernet IEEE 802.3 network cards for the ISA, EISA, MCA and PCMCIA computer buses.

[1][2] The 3Com 3c5x9 family of network controllers has various interface combinations of computer bus including ISA, EISA, MCA, and PCMCIA.

T50: Pulse transformer, pinout: 2x8 x00: Pulse transformer U4: Plastic package 33x33 pins Another chip with the same function: U6: 8192 x 8-bit 70 ns CMOS static RAM Another chip with the same function: U1: Boot ROM U3: 256 Bit/1K 5.0V CMOS Serial EEPROM Q41: N-Channel Logic level Power MOSFET 60V, 11A, 107 mΩ (using ASSY 03-0021-004 due to obscured view) VR41: 3-Terminal 0.5 A Negative Voltage Regulator (-5V) in D2PAK ASSY 03-0021-004 REV-B has written on it: U.S.

The driver for OpenBSD,[3] NetBSD and FreeBSD is "ep";[4][5] for Linux it is "eth".

The adapter also writes timing information into status registers such that a device driver can optimize for any latency.