Commodore 64 (C64) Preservation ProjectCommodore 64 (C64) Preservation Project
Vorpal - Early
Contributed by Dr. Markus Brenner

This protection is seen on many high-profile releases by Epyx from 1985-1987. Summer Games II, Winter Games, World Games, Rescue on Fractalus, Barbie, G.I. Joe, Hot Wheels, etc.
The protection was written by Scott Nelson.

The copy protection is checked on track 20. Starting from sector 1, the number of bytes between Syncs are counted for the next 17 blocks. Also, the first byte triggering the sync is read (in other terms, the last byte until the sync signal is registered). If any of these values don't match the expected values, the copy protection failed.

lengthlast byte b4 sync
Header sector 1$11$af
Data sector 1:$4d$ff
Header sector 2:$11$af
Data sector 2:$4d$ff

This project is all done in my own spare time with my own money. If you appreciate the amount of work that went into it, please donate whatever you see fit.
User Account
Greetings, Guest.

Reset Password
Create New Account

Browser cookies are required for these functions.
C64 Registry Stats
Total Registered: 4464

Top 5 Earliest Serials
Unknown: 0019
Charles Lynch: 0021
Caj Rollny: S00001044
Jeremy DuBois: S00001185
John Justice: s00001281

Latest Serial
Brian Keane:

Register Yours Today!
Disk Database Stats
Titles archived: 3625
Titles verified: 1419

View/Query Database
Find me on Facebook
All content copyright (c) 1971- by Peter Rittwage. All programs mentioned are copyrighted by their respective owners.