Overview
Publishers wanted to sell software. Users wanted to copy it. Copy protection became an arms race—each new technique defeated, each defeat spawning new protection. From bad sectors to code wheels to manual lookups, the battle between protection and cracking shaped software distribution and spawned the crack intro artform.
Fast facts
- Purpose: Prevent unauthorised copying.
- Result: Arms race with crackers.
- Side effects: Legitimate user frustration.
- Legacy: DRM evolution.
Disk-based protection
| Method | Technique |
|---|
| Bad sectors | Intentional errors |
| Non-standard formatting | Unusual track layouts |
| Weak bits | Inconsistent data |
| Spiral tracks | Physical impossibilities |
| Extra tracks | Beyond normal range |
Manual-based protection
| Type | Implementation |
|---|
| Code wheels | Physical decoder |
| Word lookup | ”Word 3, line 5, page 12” |
| Symbol matching | Match manual images |
| Dark text | Hard to photocopy |
Lenslok
| Aspect | Detail |
|---|
| System | Plastic prism device |
| Use | Decode on-screen code |
| Problems | Finicky, often failed |
| Reception | User frustration |
Hardware dongles
| Platform | Application |
|---|
| Amiga | Parallel port devices |
| PC | Professional software |
| Arcade | Security chips |
Cracker techniques
| Method | Counter |
|---|
| Disk analysis | Find protection code |
| Patching | Remove checks |
| Trainers | Bypass with options |
| Complete rewrite | Loader replacement |
Notable protection systems
| System | Platform |
|---|
| Prolok | Multiple |
| Speedlock | ZX Spectrum |
| Rob Northen | Amiga |
| Rapidlok | C64 |
User impact
| Problem | Effect |
|---|
| Backup inability | No personal copies |
| Hardware failures | Lost games |
| False positives | Legitimate copies rejected |
| Load times | Extended by checks |
Legacy
| Evolution | Modern form |
|---|
| Disk protection | Online activation |
| Manual lookups | Account systems |
| Dongles | Hardware tokens |
| Arms race | Continues today |
See also