Zed A. Shaw’s Learn C the Hard Way initially included a series of exercises focused on building a simple virtual machine, which were later removed from the final published version. These exercises, numbered 48 through 52, guided readers through creating a tiny virtual machine in C, offering deep insights into low-level programming concepts.
The final five exercises (Exercises 48–52) in Zed A. Shaw’s Learn C the Hard Way were indeed focused on building a virtual machine inspired by the DCPU-16 architecture. These exercises guided readers through implementing a simplified version of the DCPU-16, covering aspects such as instruction parsing, memory management, and basic I/O operations.
However, in the final published edition of the book, these exercises were removed. The reasons for their removal are not officially documented, but it’s possible that the content was deemed too advanced or tangential for the book’s intended audience. These exercises were eventually removed from the final published version of the book. The current edition of Learn C the Hard Way no longer contains these virtual machine exercises.