DRQ3B Replacement Module – M7658
The DRQ3B Replacement Module – M7658 (DCQ-1500) is a plug and play replacement for Digital’s DRQ3B Q-bus I/O controller. Like the DRQ3B, the DCQ-1500 is a high performance 16-bit parallel interface designed for realtime data collection or for high-speed interprocessor communications. It provides PIO and DMA transfers between a Q-bus system and external equipment at transfer rates of up to 1.3 mHz of 16-bit words.
The DCQ-1500 is hardware and software compatible with Digital’s DRQ3B. The module has two independent 16-bit channels for connection to external devices, allowing it to receive or send data or do both concurrently. Additionally, it can transfer data between two memory or I/O page locations.
The DCQ-1500 is a quad-width controller that can be installed in a variety of Digital’s PDP-11 and MicroVAX systems.
Data transfers are selectable as burst, block or extended block mode DMA. Interrupt priority levels are switch selectable and interrupt conditions are program selectable.
Like the DRQ3B, the DCQ-1500 provides transfer rates of up to 1.3 megawords per second (2.6 Mbytes per second) in extended block mode. Its double buffering capability allows the DCQ-1500 to transfer data continuously up to this maximum rate.
The DCQ-1500 is application software compatible providing a direct replacement for the DRQ3B.
The DCQ-1500 is signal and connector compatible with Digital’s DRQ3B allowing use of existing user cables and equipment.
Easy to Maintain
The DCQ-1500 is compatible with Digital’s DRQ3B diagnostics.
Controller only, Loop back cable