June | 2025 | Kurt's Thoughts

Software Copy Protection during the IBM PC days

June 28, 2025

When I was in junior high school, I used to spend my time tinkering with software copy protection. It was a fascinating topic for me because – sure I wanted copies of software that I couldn’t afford (how many 12yo do you know that could afford $1000 business database software like dBase III) – but the manner in which the software was protected was really what interested me.

There was a silent war going on between:

companies that created “software copy protection” (ex: Softgard)
companies that provided tools defeated that copy protection (ex: Central Point Software)
individuals that independently circumvented or “cracked” this copy protection by making modifications to the machine code, making the software fully functional & fully copiable (ex: crackers who posted their “warez” on BBS)

ROB SMITH’S COPY PROTECTION VIDEO
One of the best explanations and demonstrations of copy protection during the heyday of its use was done by Rob Smith in a video entitled, “How Floppy Disk Copy Protection Worked“:

ROB CRAIG’S COPY PROTECTION DOCUMENTATION
Additionally, much of this information & documentation on these era has been lost but some of it was archived by Rob Craig on his retired blog. Here are some examples of the posts he made: