Abaco Systems / SBS / Bit 3 85221510 PCI Adapter with DMA Controller Module

The Abaco Systems / SBS / Bit 3 85221510 is a PCI adapter with integrated DMA controller module that bridges PCI system memory and VMEbus architectures. It enables high-speed bidirectional data transfer through direct memory access, eliminating CPU overhead for efficient data movement between distinct bus systems.

Technical Specifications

• Manufacturer: Abaco Systems / SBS / Bit 3


• Model: 85221510


• On-Board Memory: 64 KB SRAM


• Host Interface: PCI Local Bus


• Peripheral Interface: VMEbus (A32/D32)


• Data Transfer Rates:

PCI system memory to VMEbus: up to 26 M Bytes/sec sustained

VMEbus DMA device to PCI memory: in excess of 10 M Bytes/sec

Data Transfer Widths: 16-bit and 32-bit

Bus Mastering: Bi-directional random access from either PCI or VMEbus

Interface Integrity: Parity checks on address, control, and data lines

BIOS Part Number: 85221650

Key Features

• Memory-mapped communication between connected bus systems


• High-speed DMA engine for direct system-to-system transfers


• Bi-directional random access bus mastering capability


• Independent operation of PCI and VMEbus with timing synchronization only during cross-bus references


• 64 KB onboard SRAM buffer

Typical Applications Designed for systems requiring efficient data movement between PCI and VMEbus environments, including multi-system configurations and real-time data acquisition where CPU offload is critical.

Compatibility & Integration Integrates with other Bit 3 adapters to form star, daisy-chain, or hybrid network topologies. Part of the Model 617 adapter family. Also identified as the PCI board component in configurations 608-201, 413-1, 617-201, and 487-1-201.