The Old Vintage Computing Research blog looks to reverse engineer (and strip) the copy protection off a Commodore 64 software package.

(I have a ) number of packages from back then and one of them was a secondarily acquired copy of DesignWare’s The Grammar Examiner from 1984, something like a mashup between a board game and Strunk and White’s Elements of Style, where you get to edit a fictional newspaper and fix all the typos and bad punctuation in your quest to become editor-in-chief.

So in this post we’ll explore the loader routine, decrypt and extract it, figure out how the copy protection is implemented and work around it, and then pull out the payload it reads for a faster start. While we’re at it, let’s look briefly at the program itself, an interesting example of Forth programming “in the large” on 1980’s home computers.

Read more in the post here.