Engineering:3Com 3c509

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Short description: Ethernet network card line
3Com 3c509B-Combo card (3C509BC), second generation for the ISA 16-bit bus and 10BASE-T, AUI and 10BASE-2.

3Com 3c509 is a line of Ethernet IEEE 802.3 network cards for the ISA, EISA, MCA and PCMCIA computer buses.[1] It was designed by 3Com and put on the market in 1992, followed by the improved version 3c509B in 1994.[1][2]

Features

The 3Com 3c5x9 family of network controllers has various interface combinations of computer bus including ISA, EISA, MCA and PCMCIA. For network connection, 10BASE-2, AUI and 10BASE-T are used.

The DIP-28 (U1) EPROM for network booting may be 8, 16 or 32 kByte size.[1] This means EPROMs of type 64, 128, 256 kbit (2^10) are compatible, like the 27C256.

Boot ROM address is located between 0xC0000 - 0xDE000.[1]

Teardown example, the 3c509B-Combo

The Etherlink III 3C509B-Combo is registered with the FCC ID DF63C509B. The main components on the card is Y1: crystal oscillator 20 MHz, U50: coaxial transceiver interface DP8392, U4: main controller 3Com 9513S (or 9545S etc.), U6: 8 kByte 70 ns CMOS static RAM, U1: DIP-28 27C256 style EPROM for boot code, U3: 1024 bit 5V CMOS Serial EEPROM (configuration).

Connector for the computer bus: ISA 16-bit

Connections for networking: 10BASE-T (8P8C), AUI (DA-15), 10BASE2 (BNC)

Driver setup

Some of the possible ISA I/O bases are 0x280, 0x300, 0x310, 0x320, 0x330, 0x340, 0x350. And IRQ 5, 7, 9, 10, 11, 12. The driver for OpenBSD,[3] NetBSD and FreeBSD is "ep";[4][5] for Linux it is "eth".[6][7]

Patents

3c509B-C from 1996 specify the use of U.S. Patent 5,307,459 with a priority date of 1992-07-28.

The patent describes a method where a data transfer counter triggers a threshold logic that generates an early indication or interrupt signal before the transfer is completed. The adapter also writes timing information into status registers such that a device driver can optimize for any latency.[8]

Uses

See also

  • AMD Lance Am7990 - 1985, AMD Am7990 network chip
  • NE2000 - 1987, Novell's NE2000 network card
  • RTL8139 - 1999, Realtek 8139 PCI network chip

References