Tales of Popolon (new MSXDev'17 entry)

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Por NYYRIKKI

Enlighted (5918)

Imagen del NYYRIKKI

07-07-2017, 01:51

Manuel wrote:

I did notice that in Rollerball the left flipper is corrupted... is that also copy protection?

I investigated the issue a bit and I don't think this is intentional copy protection... More like a nasty bug... The game logic works so that there are some data blocks pointed by table, pointed by table, pointed by table that are copied to address pointed by table pointed by table pointed by table. To be honest I can't really follow the actual idea, but it seems that at some point this quite a complex logic blows up causing the last data update to be sent to some pseudo random address in MSX address space instead of correct destination. When the program is stored safely in ROM this causes no damage, but when the code is in RAM this causes all kind of corruption that effectively corrupts the graphics and disables keyboard input.

Por Manuel

Ascended (18777)

Imagen del Manuel

07-07-2017, 11:41

Apparently people fixed that in the cracked disk/tape version....?

Por Louthrax

Prophet (2414)

Imagen del Louthrax

07-07-2017, 11:53

I guess you tried using openMSX and putting a memory write breakpoint for addresses 0x4000-0x7FFF in the ROM slot?

Por NYYRIKKI

Enlighted (5918)

Imagen del NYYRIKKI

07-07-2017, 14:47

Manuel wrote:

Apparently people fixed that in the cracked disk/tape version....?

I think so, but I have not found/investigated those. After doing first ugly patch for the problem (if destination address is in ROM -> move it to unused area in RAM) the graphics started to work, but after that I noticed also two other points to fix. This time this was definitely not a bug but a carefully planned attack against the vital part of code implemented by injecting entries to table that initializes values in RAM. After correcting those the game finally stopped destroying it self, but seems that developers were one step ahead. I got caught trying to crack the thing as now I end up in to demo each time I try to start a game. I bet there is still some checksum type of protection that I need to find, but unfortunately I needed to go to sleep before looking in to this. Maybe I'll have time to check it today again.

Louthrax wrote:

I guess you tried using openMSX and putting a memory write breakpoint for addresses 0x4000-0x7FFF in the ROM slot?

Yes, indeed this method was used to locate the corrupting routines (Although in 0x8000-0xBFFF)... I must say this is quite a clever protection as it uses the general routines that are important to the functionality to break the game. You can crack Konami type of protection while having your morning coffee, but this is a whole new ball game... I must say solving this puzzle is as much fun as playing the game in the first place. Smile

Por Jipe

Paragon (1551)

Imagen del Jipe

07-07-2017, 15:18

When rollerball is cracked in ram you can play but it lacks a function that allows to have an effect on the ball when you press the button several times

Por Louthrax

Prophet (2414)

Imagen del Louthrax

07-07-2017, 16:23

NYYRIKKI wrote:

Yes, indeed this method was used to locate the corrupting routines (Although in 0x8000-0xBFFF)... I must say this is quite a clever protection as it uses the general routines that are important to the functionality to break the game. You can crack Konami type of protection while having your morning coffee, but this is a whole new ball game... I must say solving this puzzle is as much fun as playing the game in the first place. Smile

Duct tape method: replacing all "ld (hl),a" (or whatever) parts of code that corrupts ROM by a call to a routine that checks the validity of the address (and pokes or not)?

Por NYYRIKKI

Enlighted (5918)

Imagen del NYYRIKKI

07-07-2017, 21:15

As Tales of Popolon really needs it's own topic, I've moved this copy protection discussion here. For latest news / discussion about speeding up ToP, please take a look at previous page.

Por wyrdwad

Paladin (931)

Imagen del wyrdwad

08-07-2017, 06:36

Got my copy in the mail today, and it plays great! My only issue is one that I tend to have with all Matranet cartridges: the actual rom card is super-loose inside the cartridge case, meaning the cartridge rattles when you move it, and always feels like it's going to come apart when you extract it from the MSX -- I always feel like I have to be super-duper ginger with Matra cartridges, or else they'll just fall apart in my hands.

To channel the Angry Video Game Nerd a little, too, I also dislike that Matranet cartridges don't have end labels on them -- have they ever considered altering their cartridge case molds to allow for that? Because I own so many Matranet games now that I have a whole case of mostly identical-looking black cartridges that I can't tell apart from one another until I remove each one and look at the front. It's a minor nuisance, but a nuisance nonetheless.

Still, the fact that I now own Tales of Popolon on officially branded physical media (and Ghost, too!) is really cool. Even if the cartridge seems kind of delicate and has no end label, it's still Tales of Popolon on a cartridge, which I feel really good about owning.

Love the box art, too. And the manual is really nice, although the Greek font makes it difficult to read some of the keys in the control section (that 0 does not look like a 0! It looks like a freaking lightning bolt!). Wink

-Tom

Por hamlet

Scribe (4103)

Imagen del hamlet

08-07-2017, 17:49

My cart arrived today.
I´m really happy with it, think it is a 25.- worth. The game is great fun (which should be the main reason to buy), packaging is great and my board fits in the housing very though. I understand your dissapointed about the "in the shelf all cartridges looks the same" label position, this is a point I don´t care because this is the way my carts are stored:

So I´m happy to get a physical release of this game, altought I think I´m more using the enchanged version for upper machines. I hope Matra and the author will get a reward for this affort, ´cause I really like the way ToP is puplished. Get a free download or a cartridge for a nice price. You decide if you want to compensate the great work.
Whambam thank you ma´am!

Por wyrdwad

Paladin (931)

Imagen del wyrdwad

08-07-2017, 18:04

Yeah, like I said, I'm really happy to own this regardless. I've been waiting for three MSX-related packages to arrive in the mail, and the Matranet one was the first to do so, so I spent a good deal of time playing both ToP and Ghost last night. It was a good way to cap off the week. Wink

-Tom

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