Old-School PC Copy Protection Schemes (2006)

IMO Dungeon Master for the Atari ST & Amiga has the greatest copy protection scheme ever created. It utilized (amongst a multitude of other things) something called "fuzzy bits" that were bits which values were not set but could be either "0" or "1" when read.

>If you copy your original Dungeon Master floppy disk using your favorite disk copier, the copy will not have the fuzzy bits but normal bits instead. The game can easily detect their presence by reading these bits several times: if it gets random results, then it assumes the disk is original. If it gets consistent results, it assumes the disk is a copy.

http://dmweb.free.fr/?q=node/210

Back in the Apple ][+ days there was a copy protection scheme that depended on the spindle speed/timing of the old Apple ][ disk drive. The original would be recorded slightly off the proper speed, but still readable (unless the timing was off the other way on your drive unit). Copies would record at normal and the software could detect that and refuse to run. An issue of the old Hardcore Computist magazine (core/apple pun intended) had instructions for adding a speed control knob to a disc ][ drive unit so you didn't have to take the cover off and use a jewelers screwdriver to adjust the potentiometer. In college I occasionally made a couple extra bucks teaching Apple software classes at computer stores. One customer had an issue with a drive unit that was spinning to fast being unable to read the software. A little bit of screwdriver work fixed it right up.

edit: Found some old digitized library of issues online. Not sure which issue it was: http://computist.textfiles.com/

My favorite were the old age verification systems. I remember my dad had the original? Leasure Suit Lary, and you had to prove you were both authentic and of age.

Authentic: enter the 5th word on page 7 of the instructions (easily foiled by a copy machine)

Of Age: who won the 1978 World Series? What is a 6th grader to do there? Phone an uncle? Go to a library or book store? I breakable... Pre internet anyway :)

I remember Elite on the ZX Spectrum had a novel scheme : a prism that you held up to the screen after loading the game to read a challenge code. Quite effective in that manufacturing a similar bit of plastic was beyond the ken of most teenagers.

Here's the wikipedia page : https://en.wikipedia.org/wiki/Lenslok

Seems to me that modern displays know how big and high res they are so could calibrate the challenge to the lens lock size, so perhaps this brand of weirdness will ride again!

I used to copy my friends' Amiga games, and by far the trickiest was one of the Worms games. The code book was black paper with glossy black text, making it almost impossible to scan or photograph.

I settled on figuring out the most freqently used page and copying it out by hand, my mum reading out the numbers as I wrote them down. Good times.

I was always partial to the copy protection in Alternate Reality: The City

>The first game, The City, also featured a novel[citation needed] anti-copying technique. The program disks could be copied though the standard methods and the copy would appear to work. However, not long after the player began the game, their character would become weaker and weaker and then die from an apparent disease.

https://en.wikipedia.org/wiki/Alternate_Reality_(series)#Tec...

Wasn't there some method where a (physical) hole was made somewhere (presumably in an unused track/sector) in the floppy so that the original floppy would work, but disk-to-disk copy operation would fail?

Then, at some point in time came along those (parallel port pass-through) dongles - I think they used to be called HASP (HArdware for Software Protection).

Earlier discussion: https://news.ycombinator.com/item?id=9151275

I remember "Manic Miner" for Spectrum had a card with a colour matrix[0] and you had to enter the correct one to play, in that time colour copies were not available or more expensive than the game. [0]http://archive.worldofdragon.org/index.php?title=Manic_Miner

Metal Gear Solid had a good one, where the radio frequency was on the back of the game art to progress in the game.

lol. That brings me back. I actually own a physical copy of "Don't Copy That Floppy" on VHS. Coincidentally we stole it from our computer teacher when I was a little kid.

The original Sid Meier's Pirates would ask you when with Spanish treasure fleet or silver train would arrive somewhere on some date. If you answered wrong, the game would still play, but you would begin at a distinct disadvantage. A skeleton crew and a leaking pinnace (the smallest ship) if I remember correctly.

I remember playing Railroad Tycoon as a kid. I never realized that the train it showed on startup was copy protection. I just thought it was a stupid guessing game that they threw in as a bonus or something, like they wanted to make sure you knew all the locomotive types before you got to them in the game.

Old school here is analog codewheel and "third word on page 75" old school hardcopy schemes (tl;dr), but I never would have played Zork III without CopyIIPC.

Robotwar (a programming game in which you program robots in a vaguely BASIC-like language and then let them fight in an arena) had a copy-protection scheme that could be defeated by, as I vaguely recall, breaking into a DOS prompt and saving files to cassette, then transferring them to a normal DOS disk.

I remember having to do this for Sid Meier's Civilization for DOS. A few turns into the game, it would ask a trivia question that was answered in the manual (which of course was missing). Eventually got good at answering the questions as the game would end if you failed.

I cut my assembler/hardware teeth diagnosing and patching the scheme protecting a PC game called Zany Golf. All it had was a bad block check, and a Phrack article on catching INT13 was all I needed to short-circuit the validation routine. Good times.

Another technique might be to randomly destroy sectors on the back of the floppy disk, e.g., using a laser. Then format the back of the disk, and record the locations containing errors, and store these locations on the front side of the disk.

DayDream BBS used to have a copy protection mechanism where when it detected being a pirated copy, it silently enabled 'shell' command for all the BBS users. I imagine that gave a pause to a few Sysops! :)

years ago, I pirated a copy of Half Life. It had what I could only assume was a way to detect cracked versions. Remember the long train ride at the beginning? That goes into the canyon and finally stops at the train platform with the guard standing outside? The guard that then has to open the door? In the version that I found, the guard didn't open the door. The guard fell over dead.

I tried again and again and the guard would still fall over dead every time. Wasn't sure if I was going crazy, or if I had just been trolled by a game developer somehow.

I had a copy (ISEPIC cart) of Beach Head II for C64. When I copied that floppy I ended up with a long black-on-green screed about how copying games was wrong. It surprised the hell out of me.

Wasn't there one where you were given a plastic prism and you had to look at the screen through that prism to see a number which you typed in?

Without the prism it just looked like random dots.

I might be imagining this.

Did these code wheel things work? All it takes is someone to go through the wheel positions and type out all the words to a plain lookup table that can be circulated as a text file.

Where in Time is Carmen Sandiego on the Amiga came with a pocket encyclopedia which was both part of the game and a copy protection mechanism.