One of the first things I did in Smalltalk (a very long time ago!) was implement Coroutines as per an article��in the seminal Byte magazine - page 336. I was especially interested in this due to my background in Jackson Structured Programming (JSP) and Jackson Structured Design (JSD), which are process based.

I also came across a thesis that has an implementation of the Blue Book, and the book itself See below.

This should get you going!

Cheers,

Stewart