The NIROS manuals contain details of all operating system updates since the previous manual; including updates to BASIC, and details of new or updated hardware. Once something has been described it will not usually be covered again in subsequent manuals unless a relevant change has been made, so to get a complete picture of the 8870 you really need all the NIROS manuals including the revision manuals.

NIROS 7.0 was the first version of the operating system to introduce multi-processor support allowing four CPUs (1559) in one system. This was a huge jump. Each CPU could have 1Mb of RAM and allowed for more users to be connected to a system installation. Because all the CPUs and devices were connected to the same backplane and there was not dedicated bus to allow the CPUs to communicate with each other, a multi-processor system didn’t run as fast as you may have hoped. I think in practical terms the system didn’t actually run any faster than a single CPU system, it just didn’t slow down as much when it was busy.