An optional Data Communications Controller can be fitted to your Nimbus to provide both synchronous and asynchronous communications at low and high speeds. This controller is the primary interface for connecting Nimbus to mainframe computers for high speed synchronous data communications and terminal emulation.

  
  
The Nimbus data communications controller has the
following features:
• Dual channel
• Support for both byte and bit oriented protocols
• A single programmable baud rate for each channel
• R5232C circuitry supporting full/half duplex transmission and modem auto-answer on each channel
• Minimal on-board data buffering: data transfers from the serial interface to the Nimbus main memory controlled by DMA, by interrupts, or by polling
• Internal or external programmable clock sources
• RS232C signals functionally compatible with Data Terminal Equipment (DTE) or DCE

This communications controller will permit different communication protocols and terminals to be emulated using either software residing in Nimbus or external dedicated protocol converter devices.
Communication data rates for this controller are:
Synchronous:up to 64K baud
Asynchronous: from 50 to 38400 baud