I have what I believe is the last version, it's V4.
Therefore, the PDF is the most recent (and last) version.
Even then, I found a bunch of glaring code listing errors that gave me fits. I walked my way through the entire book, trying each code listing that was given. I seem to remember about three or so examples that wouldn't work as printed. Figured them all out eventually, but I did a bunch of head scratching in the process.
That being said, I didn't try every function and/or test the stack diagrams for accuracy. I simply tried each example program to get a feel for the machine and how to run things.
Funny, but unless I missed it, there wasn't a single example of how to enter a GROB from the keyboard in any of the documentation. How you enter it and how it shows in the editor for viewing (or listings) is two different things. I had to resort to some web help to figure that one out.
Which brings me to the 48GX User Guide.
Went through eight (count 'em, eight!) revisions in about a year. Five in 1993 with most just a month apart, and three in 1994, also only a month apart. Signs of a rant that we've had many times before...