The Abaco Systems / SBS / Bit 3 85221511 is a PCI adapter module that bridges PCI and VMEbus architectures through an integrated DMA controller. This card enables bi-directional bus mastering from either system, permitting the PCI subsystem to function as a coprocessor or bus master on VMEbus, or allowing VMEbus devices to access PCI memory directly. The module sustains data transfer rates up to 26 MB/s from PCI system memory to VMEbus and exceeds 10 MB/s for VMEbus DMA devices writing into PCI memory. It supports both 16-bit and 32-bit data transfers with parity protection across address, control, and data lines to maintain interface integrity.
Technical Specifications
• Model: 85221511
• Manufacturer: Abaco Systems / SBS / Bit 3
• Interface: PCI (host) to VMEbus (target)
• DMA Controller: Integrated high-speed data mover engine
• Data Transfer Rates: Up to 26 MB/s (PCI to VMEbus); exceeding 10 MB/s (VMEbus to PCI)
• Bus Mastering: Bi-directional random access from either PCI or VMEbus
• Data Width: 16-bit and 32-bit transfers
• Memory: 128 KB SRAM
• Parity Checking: Address, control, and data lines
• BIOS Part Number: 85221651
• Form Factor: PCI card
• Shipped Weight: Approximately 3 lbs
– Key Features
• Integrated DMA controller for autonomous data movement between architectures
• Parity-protected interfaces ensure data integrity across all signal lines
• Supports both PCI and VMEbus as bus masters in the same transaction
• On-board 128 KB SRAM buffer
– Typical Applications
• Legacy VMEbus system integration with modern PCI infrastructure
• Real-time data acquisition systems requiring bidirectional transfers
• Coprocessor configurations where PCI acts as VMEbus master
– Compatibility & Integration
Often deployed as part of the Bit 3 Model 617 system. Software support includes loadable device drivers, example programs, and installation tools for Windows 95, Windows NT, and Sun Solaris platforms, enabling portable code development across SBS Bit 3 product lines.
