RadiSys EXM-10 Ethernet Interface Card

The RadiSys EXM-10 is a legacy Ethernet interface card for embedded PC systems using the EXM expansion interface standard. Developed by RadiSys Corporation and publicly released in October 1989, the EXM standard supports modular local I/O expansion across VME, VXI, and EMC form factors, with up to 8 expansion modules per embedded PC. The card’s 16-bit EXM bus interface is electrically similar to the PC ISA bus, enabling compatibility with standard PC software. The EXM-10 provides 10 Mbps Ethernet connectivity and emulates Western Digital WD8003EB controllers, while the EXM-10A variant emulates WD8003E, WD8013, Novell NE2000, and NE2000+ controllers. Multiple physical Ethernet connectors are available on EXM-10A models: 10-base-T twisted pair, 10-base-2 thin Ethernet (BNC), and AUI transceiver ports via DB-15 DIX/MAU connectors for thick Ethernet or alternative media types.

– Technical Specifications

• Bus Interface: 16-bit EXM expansion interface with 116-pin card-edge connector
• DMA Channels: DRQ0–DRQ3 for 8-bit transfers; DRQ5 and DRQ6 for 16-bit transfers; DRQ4 reserved for system board
• Configuration Registers: Addressable at 100h, 102h, and 103h in local I/O space; EXMID signal selects active EXM slot
• I/O Channel Check Signal: Provides parity error information for memory and I/O channel devices
• Ethernet Media Support: 10-base-T, 10-base-2, and AUI transceiver connectivity

– Key Features

• Compatible with standard PC ISA bus software
• Supports up to 8 expansion modules per embedded PC system
• Dual controller emulation options (EXM-10A)
• Enhanced noise immunity: 15 GND lines and inverted RESET signal
• Operates independent of SA17–SA19 address lines; uses LA17–LA19 instead

– Typical Applications

• Embedded PC network connectivity in industrial control systems
• VME and VXI chassis-based computing platforms
• Legacy system modernization and integration

– Compatibility & Integration

The EXM-10 integrates with embedded PC systems supporting the EXM expansion standard. EXM-10A models provide backward compatibility with WD8003E/WD8013 and Novell NE2000-series driver stacks. The card’s ISA-equivalent electrical architecture ensures compatibility with existing PC-based network software. Status is legacy; availability through third-party suppliers beyond manufacturer EOL.