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Alternate Reality - The City protection scheme?


Wilheim

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It's not such the disk 1 copy protection you need to he concerned with as the images people run under emulation with have that sorted.

 

The whole game uses a replacement SIO routine and pattern based decoding.

 

On top of this the copy protection routines are implemented multiple times, e.g. the game uses overlays of code (handling being a bar for example) and these have their own routines.

 

Read the threads/posts I have done on this already or if you want to collaborate then PM me.

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8 hours ago, Wilheim said:

Hi!

 

Does anyone know what are the physical protection from the disks of this game?  Is there a fuzzy sector? In which disk? Or an extended track?

 

I would like to know that in order to detect where are the copy checking routines.

Disk 1 Side A only - Two versions, one has weak sectors on Track 17, the alt just CRC errors.

 

Alternate Reality - The City (1985)(Datasoft)(US)(Disk 1 of 2 Side A)[!]

 

T0 - Deleted Data & CRC s9, 11-15, T1 & 3 - Unformatted, T17 - Phantom & Weak s9-13 x2, T18 - Phantom s2-6 x3, s7 x2, T19 - Phantom s1-4, 6-7 x2, s18 x6, T20 - Phantom s1-4, 6-7 x2, s18 x6, T39 - Phantom s1, 3, 5, 7, 9, 11, 13, 15 x2

 

1952235261_AlternateReality-TheCity(1985)(Datasoft)(US)(Disk1of2SideA)!.thumb.jpg.e0839d2ee054c1d2217a8b538cf8a14c.jpg

 

Alternate Reality - The City (1985)(Datasoft)(US)(Disk 1 of 2 Side A)[a][!]

T0 - Deleted Data & CRC s9, 11-15, T1 & 3 - Unformatted, T17 - CRC s9-13 x2, T18 - Phantom s2-6 x3, s7 x2, T19 - Phantom s1-4, 6-7 x2, s18 x6, T20 - Phantom s1-4, 6-7 x2, s18 x6, T39 - Phantom s1, 3, 5, 7, 9, 11, 13, 15 x2

 

564877478_AlternateReality-TheCity(1985)(Datasoft)(US)(Disk1of2SideA)a!.thumb.jpg.64cff1c5d668d14f1f72d127ce91f5ac.jpg

 

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Can't  add any details except that I thought I'd  toss my 2 cents in... Back in the day I cracked several games for myself and my friends.  I was never any kind of expert,  but I was succesful many times.  I bought AR  City;  had it backordered for many months.  When I finally got it,  I was amazed by it (hell,  I still play it once or twice a year NOW,  35 years later,  still continuing my original character).  I gave it my best try to crack it for my friends... With no success.  I think it started with a fuzzy sector. Easy.  But then it did multiple levlels of encryption.... These sectors EOR'd with those sectors... Run... Then load more sectors EOR with others,  then perform operations on those multiple results. 

 

Somewhere in the original disks was the text "protection from paradise", and I agree. Insane levels of protection at the time. 

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