Asynchronous Multiplexer
I wanted my PDP-11 to have some serial ports for machine-to-machine connectivity, as well as for peripherals. Probably the best Q-bus serial module available is the M3107 DHQ11 asynchronous multiplexer. This module has 8 serial ports, supports DMA transfers, modem control, and speeds up to 38400 bps. It has throughput of 60,000 characters per second.
My DHQ11 is shown below.
The DHQ11 requires a break-out assembly, which I will have to build. I plan to build a circuit board that can take standard 40-pin ribbon cables and break them out to DB-25 and/or DB-9 connectors.
References
- DHQ11 User Guide, 2nd Edition, July 1987 (EK-DHQ11-UG-002)
