ISA8 Ethernet

ISA 8-Bit Ethernet Controller

ISA 8-Bit Ethernet Network Interface Controller

Introduction

ISA 8-Bit Ethernet Controller is an open source network interface controller (NIC) card, designed specifically to be used in computers with 8-bit only ISA (aka XT) bus, such as IBM* PC, IBM* PC XT, various PC/XT compatibles, for example Micro 8088 system. It is based on Realtek RTL8019 ethernet controller and is NE2000-compatible.

Specifications

• ISA 8-bit interface (62 pin / card edge)
• NE2000 compatible
  • Note: Popular Crynwr NE2000 pocket driver does not support NE2000 in 8-bit slots. Please use the patched driver instead
• Supports configuration using switches, jumperless configuration using RSET8019 utility or PnP
  • Uses DIP switches instead of jumpers for reliability and ease of configuration
• Boot ROM support
  • Socket supports 512 KiB Flash ROM, such as SST/Microchip 39SF040
  • Can be configured in 16 KiB, 32 KiB, 64 KiB, or page mode. In page mode the entire 512 KiB are accessible through a 16 KiB window
  • Also compatible with other DIP 32-pin Flash ROMs, such as 128 KiB 39SF010A, and 256 KiB 39SF020, or similar
  • 40-pin memory extension connector allows connecting up to 4 MiB of memory that can be used in page mode

Hardware Documentation

Schematic and PCB Layout

Schematic - Version 1.0

PCB Layout - Version 1.0

Building Instructions

Assemble the PCB

• Clean the PCB with alcohol
• Apply fluid flux to SMD components pads
• Solder U1 RTL8019 IC
• Solder R1 - R7 resistors and RN1 - RN4 resistor arrays
  • Note that RN1 - RN3 are only required if using DIP switches for configuration. They are not required for jumperless configuration
• Solder C1 - C8 ceramic capacitors
• Solder C9 and C10 tantalum capacitors
• Solder Y1 crystal
• Optional: Program U3 EEPROM. Make sure to use unique MAC address
  • Note: EEPROM can be programmed later using PG8019 utility
• Solder U3 EEPROM
• Optional: Solder SW1 - SW4 DIP switches and U2 IC socket
• Solder J1 Ethernet jack with integrated magentics
• Clean the remaining flux with alcohol

Program EEPROM

If EEPROM has not been programmed prior to assembly, now it is a good time to do so. The U3 EEPROM contains the following configuration for the RTL8019AS chip:

• MAC address
• ISA resources for jumperless configuration
  • Base I/O address
  • IRQ number
  • Boot ROM mode, size, and base memory address
• Other ethernet controller confirguration - medium type, full duplex, LEDs function, power management settings
• Product ID (not normally used, although some vendor specific drivers might check for it)
• Plug and Play data
  • Vendor ID, serial number, PnP version, I/O, memory, and IRQ resources

This information can be programmed using PG8019 utility. The 8019AS.CFG file contains the recommended configuration. Make sure to edit it, and update the MAC address and the serial number. Note that the MAC address is given in the Big-endian format (that is the last byte has the least significant value), while the serial number is given in Little-endian format (that is the first byte has the least significant value).

A few notes about using PG8019:

• Make sure that your system has 0x300-0x31F I/O addresses available regardless of the Ethernet controller addresses specified in 8019AS.CFG. Note that XT-IDE and XT-CF-Lite frequently use this I/O range. In case you have such a card, you can either temporarily remove it from your system, boot and run PG8019 from a floppy disk, or switch your XT-IDE or XT-CF-Lite to a different address. In the latter case you'll need to update the XT IDE BIOS configuration
• Make sure that your system boots in real mode (no EMM386), or anything else that might interfer with the card. Ideally boot your system without any drivers loaded at all, for example, in later MS-DOS versions it is possible to bypass CONFIG.SYS and AUTOEXEC.BAT by hitting F5 key at the boot time
• After EEPROM has been programmed successfully, the PG8019 utility will print the MAC address, also, it will automatically increment the MAC address and the serial number in 8019AS.CFG, which is useful when programming multiple cards

Openmoko Inc. has generously allocated 00-1F-11-02-60-00 - 00-1F-11-02-7F-FF MAC addresses range for ISA 8-Bit Ethernet controller project. You can use MAC addresses from this range for your build, as long as you are using this design. Please apply for a different range if you're redesigning the board or re-using this Ethernet controller design in your own project. I ask you not to use 00-1F-11-02-60-00 - 00-1F-11-02-63-FF range (first 1024 addresses). I am using this range for the cards that I build.

Test Ethernet Controller

• Connect Ethernet cable. Make sure that the green "Link" LED lights up
• Use mTCP to test the controller
  • DHCP to obtain IP address
  • FTP or HTGET to download a file

Switches and Connectors

SW1 - CONFIG

This switch block sets the configuration mode

SW2 - IRQ

This switch block, when the card is in the Switches configuration mode, sets the Ethernet controller IRQ

SW3 - IO_ADDR

This switch block, when the card is in the Switches configuration mode, sets the Ethernet controller I/O address

SW4 - ROM_ADDR

This switch block, when the card is in the Switches configuration mode, sets the Ethernet controller boot ROM address and size

J1 - Ethernet Connector

J2 - MEM_EXT

This connector can be used to add up to 4 MiB of optional memory (ROM or RAM). The memory, if larger than 64 KiB, can be accessed using the page mode.

Bill of Materials - Version 1.0

ISA 8-bit Ethernet project on Mouser.com - View and order all components except of the PCB and the Realtek RTL8019 IC.

ISA 8-bit Ethernet project on OSH Park - View and order the PCB.

Reference Information

Realtek RTL8019AS EEPROM Content

The Realtek RTL8019AS uses 93C46 - 1Kbit / 128 bytes EEPROM to store the configuration. The EEPROM is accessed using 16-bit word mode, with data being stored in Big-endian format. This means that the bytes should be swapped when the EEPROM content is accessed on an x86 system.

Red Tape

Licensing

ISA 8-bit Ethernet is an open source hardware project certified by Open Source Hardware Association, certification UID is US002001. The hardware design itself, including schematic and PCB layout design files are licensed under the strongly-reciprocal variant of CERN Open Hardware Licence version 2. The NE2000 driver code is licensed under GNU General Public License v2. Documentation, including this file, is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

KiCad symbols and modules used in this project are available in my KiCad library repository