The link below is to a sample from an ongoing project to digitize Xywrite user manuals.
The format was created using the XPP composition engine (Xyvision).
From XPP a postscript file is created, which is then distilled to PDF.
This sample is pretty close to what the finished manual will look like.

A sample of XyWrite III's manual (PDF)

(from Acknowledgements through Chapter 2)