The Prolok Saga (Was: Applesauce FDC

Ali cctalk at
Tue Nov 2 18:11:44 CDT 2021

> 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).

Which could be defeated w/ the Copy II Plus Enhanced Option board:

This board had a small bit of onboard RAM that would load info about the

"EOB has an extra circuitry that allows it to emulate a burn-hole in a
diskette and cause a running application to think that the original
diskette is present inside the drive. As it can be understood, the copy
of a burn-hole protected diskette can only be executed on a computer
equipped with the standard or deluxe EOB.

In order to create a working copy of a diskette that is protected by a
physically damaged media, the diskette has to be copied using the regular
option board methods (TC/TCM), and then the EOB utility PK.COM must be
executed in order to analyze the original diskette and locate the exact
place of the burn-hole. Once the place has been found, PK saves the data
in a file for future use.

Every time before the copied diskette is used, the PK application must be
executed with the filename that contains the information as a parameter.
Then, PK will program the EPROM that is present on the EOB, according to
the information inside that file.

Whenever the copy protected application tests for the original diskette
and tries to read from (or write to) the physically damaged sector, the
EOB emulates the very exact behavior of a physically damaged media at the
exact place where the burn-hole was, thus confusing the application to think
that the original diskette is present inside the drive."

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