February 6, 2026
Insert disk, pray
PC Floppy Copy Protection: Vault Prolok
Floppy Disks with a Booby Trap? Geeks Nostalgic, Lawyers Screaming
TLDR: Vault’s Prolok used pre-damaged “fingerprint” floppies and could erase data if piracy was suspected. Readers split between fond nostalgia and fury at the “break their stuff” approach, calling it a liability nightmare—proof that aggressive anti-piracy can backfire on real customers.
Old-school drama alert: Vault’s 1983 Prolok copy protection didn’t just lock software—it used pre-damaged floppy disks with a unique “fingerprint,” and if the check failed, it could erase your data. Big names bought in (even dBase maker Ashton-Tate invested), and ads bragged it would end piracy forever. The comments? A split-screen of vibes and alarm bells. One veteran reader beams, “good interesting read,” soaking in the retro wizardry. But another voice slams the “break their stuff” approach as ludicrous, calling out the nightmare of bugs and legal liability if a legit user gets nuked. That last bit isn’t hypothetical—compatibility issues did force Vault to replace some wiped media. Yikes.
The drama centers on nostalgia vs. collateral damage: Was this bold protection or a ticking time bomb in your PC drive? Readers mock the “end of piracy” promise and imagine support calls from users whose work just vanished. Cue the inevitable jokes: think “Mission: Impossible” self-destructing tapes and floppy disks with mood swings. For a product detailed in US Patent 4,785,361, the community takeaway is simple: smart idea, reckless execution. And if your anti-piracy plan risks wrecking customer data? The internet’s verdict is loud—don’t.
Key Points
- •Vault Corporation launched Prolok in 1983, supported by major advertising and industry positioning.
- •Ashton-Tate used Prolok in dBase III v1.0 and Framework 1.0 and invested $500,000 for a 20% stake in Vault.
- •Prolok employed a deliberate disk surface defect (“fingerprint”) rather than non-standard formats for copy protection.
- •Prolok was distributed as pre-damaged diskettes; publishers used PROLOK.EXE to encrypt and wrap software on these disks.
- •The Prolok patent describes enabling reads if a fingerprint is present and erasing protected material if it is absent; early media saw inadvertent erasures and were replaced.