Questions tagged [copy-protection]

For questions about copy protection techniques used on retro software.

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21 votes
1 answer

How did "Super Wonder Boy (in Monsterland)" defeat the Multiface One?

The Multiface One was a memory dumper for the ZX Spectrum 48K with a button that generated an NMI to run code in its ROM that could dump the machine state to mass storage (CMT/cassette tape, diskette, ...
cjs's user avatar
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13 votes
1 answer

Did RapidLok etc knock floppy drives out of alignment?

From But balanced against the one great advantage of RapidLok for the legitimate user was at least one ...
rwallace's user avatar
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24 votes
3 answers

How were Amiga games cracked circa 1987?

I remember getting my Action Replay MKIII cartridge on my A500 in 1992, and from there I could remove protections (manual/code & physical) of a lot of games. The MKI & MKII existed before 1991 ...
Jean-François Fabre's user avatar
12 votes
1 answer

Why can SafeDisc disks be read faster if the game was opened before?

First of all I want to say I have the games in real and I am just making safety backups. The disks are old and tend to lose data. I am using Alcohol 120 Retro edition and found something weird. I have ...
zomega's user avatar
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26 votes
2 answers

Which software was the first to use copy protection?

While researching early magnetic storage around 1980, I've come to ponder if we know of the first piece of software on removable media that employed copy protection? The Wikipedia article mentions ...
Micropolis's user avatar
12 votes
3 answers

Disk copy protection schemes for Apple II

I have a vague recollection back in the late 70s of using a wonderful program called Locksmith (from memory, so I could be wrong). It apparently could handle all the different ways that disk-based ...
paxdiablo's user avatar
  • 4,594
2 votes
0 answers

Was the SNES really a "highly pirated" console? [closed]

I just watched the YouTube video How Nintendo Stopped Bootleg Games on the Nintendo 64. The presenter claims that the SNES had a massive pirate scene and you could "easily buy" one of ...
Huntlee's user avatar
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6 votes
3 answers

Were commercial Amiga floppy disks shipped with write protection?

In this Amiga "quick kickstart guide" magazine thing that I have from when I bought an Amiga 1200 long ago (it seems to be printed in late 1995), they really go out of their way to point out ...
Amiganu's user avatar
  • 69
8 votes
1 answer

What's the point of the CPS-2 suicide battery?

The CPS-2 arcade board contains a suicide battery that will force the board to kill itself when it runs below a certain power threshold. Supposedly this was created to mitigate piracy of the games, ...
Badasahog's user avatar
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2 votes
2 answers

Why does changing a DOS/Windows EXE cause it to not run? [closed]

If I hex-edit an EXE for DOS or Windows, by adding or removing some text for example, it will no longer run. If I just change a single char around to a different one, it may run. Is this some anti-...
Majdi Hasting's user avatar
3 votes
1 answer

Where can this "boot.B" file be coming from on this Spectrum TR-DOS disk image?

After working on some tools that parse the TR-DOS disk image format .TRD files for a while I just noticed that one of the game disk images I had downloaded "La Abadia Del Crimen", only has three files ...
hippietrail's user avatar
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7 votes
1 answer

What is the Nintendo 64 IPL3 and how could it be created by Rust developers?

I was delighted to learn there is an integrated toolchain for Rust development that supports the Nintendo 64. According to the documentation: For copyright purposes, the IPL3 binary is not included ...
Brian H's user avatar
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3 votes
3 answers

Pirated spreadsheet software introducing intentional errors?

Was there ever a case of a spreadsheet application introducing intentional floating-point errors when it detected that it had been pirated? Particularly errors that were small enough to go unnoticed ...
micheal65536's user avatar
14 votes
8 answers

Copying tapes "back in the day"

Back when I had a ZX Spectrum 48K, I had a friend that had a 128K and we would swap games for the weekend from time to time. We did try and make duplicates of the tapes (yes, I know, but we were ten ...
Recycled Steel's user avatar
43 votes
3 answers

How did Apple II BASIC programs protect against listing?

I seem to recall from my high-school days that certain Apple II programs protected themselves from being listed and therefore modified. If you tried to do it, the machine would simply reboot. How did ...
user avatar
14 votes
2 answers

Weak bits on floppy for copy protection

How did the vendors using copy protection create weak bits on the floppies? This always fascinated me as a kid. I ended up finding a weak bit emulator that would intercept the floppy disk interrupt ...
enorl76's user avatar
  • 249
4 votes
3 answers

How can I view BASIC code hidden by SYS?

I ran a validation of an old disk, and it turns out this ruined a game (won't load) and deleted my old high score list on David's Midnight Magic. I would like to edit the code to get the high score ...
Canned Man's user avatar
5 votes
0 answers

Rainbow Technologies Ltd DRM system for DOS

A number of games from the early 1990s appear to be protected with a DRM system developed by Rainbow Technologies Ltd. The system allows content in the games to be unlocked by sending the manufacturer ...
user's user avatar
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10 votes
4 answers

Was the Amstrad's file protection considered secure in 1985?

I just reverse engineered the file protection on the Amstrad CPC, which uses two sequences of rotating bytes taken straight out of the AMSDOS ROM to XOR each byte of the file. If you have SEQa of 13 ...
CJ Dennis's user avatar
  • 2,527
14 votes
2 answers

How was Prince of Persia "better/faster" with RWTS18?

I was reading about Prince of Persia over at POP Code Review. In that article, the writer printed an interview with Roland Gustafsson, the inventor of RWTS18 copy protection for the Apple II series. ...
cbmeeks's user avatar
  • 8,441
8 votes
3 answers

Advantages to installing a parallel port in a C1541-family drive other than speed

Are there any advantages to installing a parallel port in a C1541-family drive and using a parallel cable to a PC to image disks, other than increased speed (i.e. since the standard IEC protocol is ...
echristopherson's user avatar
22 votes
3 answers

How did "full memory" Spectrum tape copiers work?

There are some tape copiers, such as LERM that claim to be able to copy tapes which contain software that takes the full 48kbyte of RAM. However, this seems impossible on a Spectrum, when the whole ...
Sklivvz's user avatar
  • 1,233
32 votes
1 answer

How does "bit-slip" copy protection work?

Some Apple II 5.25" floppies used a special pattern of bytes that could not be automatically detected by disk copying software. How could the pattern be invisible to disk copiers but detectable by ...
fadden's user avatar
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