The Arcade Game that Crashes Itself for Anti-Piracy Reasons

Using the player's continuously changing score to quietly crop-dust the game's own code with errors is just beautiful in its elegant malice.

Finally, an actual anti-piracy screen

The anti-piracy game corruption techniques are honestly hilarious. I love the little devious methods old school software used.

Ah yes, The Pokey Chip. Right there next to the Shadow Chip, the Speedy Chip, and the Bashful Chip.

one reason why they likely bound the checksum to the copyright notice specifically is that it gives them an extra legal avenue to pursue in that they aren’t just altering the code to work, they would have to fraudulently misrepresent something with altered copyright information as that’s the only valid set of values. that’s why for example, the sega genesis would display ’licensed by sega’ etc, because an unlicensed game would cause that message to display and essentially become a legal claim. there were some interesting court cases around this, and i imagine the copyright notice here being the checksum serves a similar function.

The checksum mattered to ATARI because pirates would remove copyright messages, allowing arcade owners and bootleg manifacturers to go "but I didn't know" by "forcing" copyright messages, ATARI could then point to the copyright notice, and claim that they had to know, they were told on the title screen.

One fun thing about the graphical glitches, if displayed on a real machine there is a chance the monitor will be damaged. WG K6100s are pretty delicate, if the deflection input is out of range (ie drawing shit outside of the normal bounds of the screen) it can cause too much current to flow through the transistors that drive the yoke, causing them to short, blowing out the voltage regulator transistors and causing you to have a very sad monitor. Almost anyone who has or had a color vector atari machine knows the pain. They're pretty annoying to repair.

It is interesting that if the game's software or hardware is modified, you will still have a free trial, but then the game breaks completely after the trial ends.

With how formal and instructive your videos always are, that little "...apparently" caught me off guard, I probably laughed much harder than I should have

I remember during a behind the scene video about Tempest, there was a glitch/failsafe that if the copyright wasn't in a specific place, the game would automatically add a large number of free credits. this kept machine owners/renters form using unlicensed products.

I once went to an arcade, it’s probably been five years since this happened, but it was one of those typical “we put smartphone games on a bigger screen and called it a day” type of arcades. Yet, for some reason, literally sitting UNDER a set of stairs, there was a Tempest machine. You know damn well what ensued afterwards. Best arcade I’ve ever been to, not that that’s saying much, since most of them don’t even have anything besides the aforementioned smartphone games, and I haven’t been to all that many. (By the way, this wasn’t some reproduction or an emulator in a box. It was a genuine musty old piece of work, and why it was in this place, I have no clue.)

I would assume that the reason the checksum only checks the atari copyright text is so that anyone who makes an illegitimate copy of the game can be sued on the grounds of copyright infringement, similar to how nintendo used their logo for legal copy protection for the gameboy.

Mess with our game? Sure Mess with our name? Absolutely not

Emperor of the Fading Suns had a devious method - if you failed or otherwise found a way to by-pass the anti-piracy check, they would let you play the game and it might seem like everything was playing normally, but as you went along it would slowly start subtracting cash from your treasury. The longer you played, the more it would subtract, so by the time you realized what was going on and found yourself mysteriously bankrupt, you had already invested a huge amount of time into the game, which was now guaranteed unwinnable.

*Reveals that the name of Atari's RNG producing chip is called the "Pokey" Chip. The Five-Year Old in the back of my brain: "You do the hokey-pokey and you turn yourself about. That's what it's all about!"

This was rather interesting. Years ago I was quite heavily involved involved with software and hardware development on PCs. One anti piracy technique I developed was based on floppy disk storage. The way data is normally stored on disk is as a series of Sectors on each track. Each sector is numbered but generally, not (as you might expect) in order. Instead, the sectors were arranged so that, after reading the sector No 1, you'd skip the next and then the sector after that would be Sector No. 2. This would give the bios time to be able to process the first sector before reading the second. After a complete rotation of the disk, you'd then have half of the sectors on that track. A second revolution would follow the same pattern but reading the alternate sectors that had been skipped on the first revolution. So it would take two complete revolutions of the disk to read one complete track. This was actually faster than having the sectors in order because if the bios missed the beginning of just one sector, it would have to wait a full revolution of the disk to get back to the missed sector. Having an intervening sector made this less likely to happen. Now for my anti piracy method, I'd run a custom low level format on the disk, such that one track (eg. track 7) had all the sectors stored in reverse order. This made the time to read that track take much longer to read than any other track. (typically 16 revolutions of the disk compared to 2). Once the disk had been put through this low level format, it could be written to in the normal fashion but when reading that track, it would take 8 times as long to read, compared to the other tracks on the disk. If anyone ever used standard tools to copy the disk, all the data would be perfectly copied over BUT, when reading that track, it would read at the same speed as any other track. Thus giving away that it was not an original copy. The beauty of this was that the client could even format the original disk (using the dos Format command) and download an updated version of the software and write it to the disk and it would still work. (formatting doesn't overwrite the low level format, it uses the existing sector markers). So effectively, there was nothing to see in the software, it was the disk itself that had been "marked" as authentic. I used some similar methods on CDs and obviously we had other techniques at our disposal. I was asked to implement a process that would copy the serial number of the CPU onto the floppy disk on first setup to bind the software to that one machine, but I refused to implement that, as I felt, if someone has paid for a copy of the software, they should be allowed to upgrade their machine without loosing functionality of our software.

For anyone wondering why the copyright string is so specifically protected, it was common practice in the day for bootleg arcade machines to alter the data, which at the very least would generally include a different title and copyright string. Essentially this was done in the hope that they could technically say, for example, "we weren't distributing unauthorized copies of Mario Bros, this is Pest Place!"

Turning on decimal mode is a delightfully simple way to break the game.

Never did I think a video about some random arcade game’s anti piracy would captivate me for 30 minutes.

The amount of sass and spite in this protection is unparalleled. Love it.