The Prolok Saga (Was: Applesauce FDC

Alexandre Souza alexandre.tabajara at
Tue Jan 4 04:47:23 CST 2022

Fred, a completely unrelated piece of information, but interesting

Elnec device programmers are very famous for the number of devices it
programs and its robustness. Also for their clones. If you open a cloned
beeprog you cannot differ it from an original beeprog.

I still haven't completely reverse engineered the protection, but it seems
to be related to the serial number. If any host software beyond 2.63
detects a "fake programmer" it BRICKS the cloned prigrammer. Yes, rends it
useless. You gotta reprogram a pair of eeproms and a pic to make it work
back again.

You told about the prolok plus erasing hds and I remembered of this atitude
from elnec. And no, I know of no one that sued elnec for bricking their
clone programmer.

So bad. They are great programmers, I have an old beeprog.

73 de pu2sex Alexandre

Enviado do meu Tele-Movel

Em ter, 2 de nov de 2021 17:35, Fred Cisin via cctalk <cctalk at>

> On Tue, 2 Nov 2021, dwight via cctalk wrote:
> > The trickiest protection I've seen is where there is a hole punched
> > through the disk on one track. The idea is that the protected program
> > writes to that track and expects to see a failure to read that track.
> It doesn'tneed to be a hole all the way through, merely any physical
> defect that renders that spot unusable.
> The "Physical Defect" protection.
> Copy protected disks had already been made with flawed content to produce
> an error on READ, and were easily circumvented by the "duplicate" copy
> having flawed content. The next step was to have a physical defect, so
> that the protection software would WRITE to the bad track, and confirm
> that the track really was damaged.
> So, they would scratch the disk.
> In the case of Prolok, the check to confirm a physical defect consisted of
> writing all zeroes to that area; verifying all zeroes; writing all ones;
> and verifying all ones.
> Vault Corporation produced "Prolok" with a physical defect.  To make it
> MUCH MORE IMPRESSIVE to investors and clients, instead of a roomful of
> people scratching disks with paperclips, they used a "laser fingerprint"
> (use a laser, instead of a paperclip).
> Since they gave the same or similar subroutines, that checked for the
> defect, to every client, it was cracked with software that would locate
> that subroutine, and replace the subroutine call with NOPs or gut the
> innards of the subroutine.  The cracks were often posted on Compuserve.
> (Vault sued Quaid software for "CopyWrite"/"RAMKEY")
> )
> For "cloning" (pirating copies, often with the Central Point Option
> board (flux hardware)), software was developed that would
> identify the location of the defect, the cloner would then attempt to
> scratch the disk at that location, and then the software would locate the
> defect and juggle stuff around to put the content in the right place(s)
> relative to the defect.
> But, Vault Corporation wasn't satisfied until they shot themselves in the
> foot with very high caliber rounds.
> They announced "Prlok PLUS".  W. Krag Brotby (chairman of Vault) said that
> it would, if it detected a "fake" copy, wipe out the user's hard disk!
> Even at the announcement of Prolok PLUS, the computer marketing
> community was aghast and enraged.  It doesn't take much to realize the PR
> nightmare, and the legal liabilities for damaging a customer computer,
> even if it was NOT a false positive!
> Ashton-Tate, the largest Prolok client for dBase III, and part
> owner of Vault, immediately cancelled their contracts.  And announced
> that they had done so, that they had never used Prolok Plus, never would,
> and no longer used Vault Corporation products.
> Almost all of Vault's other clients follwed suit.
> Prolok Plus never made it to market!
> 'Course the "word was out".  Few people realize that it was NEVER
> actually put to use.  In fact some of the more idiotic newspaper "solve
> your computer problems" columnists, when stumped, would actually speculate
> "maybe your computer was attacked by an out of control copy-protection
> program."
> So, we ended up with a mythical monster, and the creator of that mythical
> monster was vanquished.
> If anybody can document an actual existence of Prolok Plus, I would like
> to hear about it.
> There is little mention of it on the web, but:
> "Re:Ahhh, holes burned in disks (Score:5, Informative)"
> Kryoflux display of Prolok
> --
> Grumpy Ol' Fred

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