The Abaco Systems / Radstone PME 68-42 is a VME Single Board Computer engineered for high-performance real-time applications requiring intensive I/O and computation. Its dual-processor architecture pairs a Motorola 68040 primary processor with a dedicated Motorola 68020 I/O processor operating at 20 MHz, enabling parallel processing and reduced latency in VMEbus environments. The “Freeflow” architecture maintains multiple independent internal and external data paths to minimize bus contention and I/O conflicts.
Technical Specifications
Processors & Memory
• Primary processor: Motorola 68040
• Dedicated I/O processor: Motorola 68020 @ 20 MHz
• RAM: Up to 36 Mbytes distributed multi-port
• EEPROM: 512 bytes configuration storage
I/O Interfaces
• SCSI: Full CCS support with SCSI-2 command tagging and queuing; synchronous transfers to 6.25 Mbytes/sec or asynchronous to 5 Mbytes/sec; 32-byte on-chip FIFO with DMA controller
• Ethernet: On-board with integrated DMA
• Serial: Four ports driven by two Z85C30 Enhanced Serial Communications Controllers; two ports support RS232C asynchronous to 2.048 Mbits/sec, HDLC, SDLC, X.25, or BISYNC modes; two ports RS232C asynchronous only; optional RS422/RS485 configurations available
• VMEbus: A32/24 and D64/32/16/08 master/slave operations via P2 user-defined pins
• APEX interface included
Firmware
• CIOS (Concurrent I/O Server): Full SCSI support and I/O management
• BIOS PROM: Hardware drivers and I/O management functions
– Key Features
• Dual-processor offloading reduces primary CPU overhead
• Independent data paths minimize transfer conflicts
• Multi-port RAM architecture supports concurrent access
• Full SCSI-2 compliance with DMA burst capability
• Flexible serial port configurations for synchronous and asynchronous protocols
– Compatibility & Integration
Supports UNIX System V, VRTX32, Velocity, VxWorks, OS-9, and other real-time operating systems and kernels. B-size 6U VME form factor. 68000 family instruction set compatibility maintained.
