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.

Whilst there is a lot of good stuff in this manual, the 5.0 manual would have contained details of the big ticket items and changes from 4.0.