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General Category => Technical Support => Software related => Topic started by: Lazy Dude on 18:23, 11 July 15

Title: Prohibition prohibited!!
Post by: Lazy Dude on 18:23, 11 July 15
I was hoping to get the 128k version up and running on the 6128, but its not behaving  :(

so taking the Nick Campbell version 64k works ok but 128k version erases from memory instead of returning to start menu after loosing all lives. Odd!

Trying the Original version available on CPC Power the 128k version does not play correctly as it has a super speedy countdown timer!

Any ideas? Maybe buy a Spectrum?

Cheers
Title: Re: Prohibition prohibited!!
Post by: Joseman on 18:28, 11 July 15
I was hoping to get the 128k version up and running on the 6128, but its not behaving  :(

so taking the Nick Campbell version 64k works ok but 128k version erases from memory instead of returning to start menu after loosing all lives. Odd!

Trying the Original version available on CPC Power the 128k version does not play correctly as it has a super speedy countdown timer!

Any ideas? Maybe buy a Spectrum?

Cheers

The speedy countdown timer sound like copy protection... what program do you used to save to floppy?

buy a Spectrum... if you have a Ferrari why you will buy a Dacia Logan?
Title: Re: Prohibition prohibited!!
Post by: Lazy Dude on 18:35, 11 July 15
I'm using cpcxp and burning it to an internal floppy just like all the other games I been playing
Title: Re: Prohibition prohibited!!
Post by: Nich on 20:38, 11 July 15
I was hoping to get the 128k version up and running on the 6128, but its not behaving  :(

so taking the Nick Campbell version 64k works ok but 128k version erases from memory instead of returning to start menu after loosing all lives. Odd!

This is an old crack that I worked on a long time ago. From what I remember, I had problems working out how to save the high score table to disc on the 128K version, and I never did find out how to fix it - which is why the 128K version crashes! :(

Fixing it will be yet another thing to add to my "to do" list, then...
Title: Re: Prohibition prohibited!!
Post by: Lazy Dude on 22:35, 11 July 15
Ahh there you go!
Thanks for posting  your reply. I think any effort people have made to make the games accessable after all these years is great.
I still got the original tape version, which I loved to give a good thrashing.

Thats it, back of the queue for me on seeing that one sorted then!!
Ha ha no worries
Title: Re: Prohibition prohibited!!
Post by: Nich on 23:14, 20 July 15
I prepared a new crack of Prohibiton (both 64K and 128K versions) over the weekend and I have just uploaded it to NVG:

ftp://ftp.nvg.ntnu.no/pub/cpc/games/arcade/prohibit.zip (ftp://ftp.nvg.ntnu.no/pub/cpc/games/arcade/prohibit.zip)

Note that the game does not work on Plus machines. :( This seems to be because it uses interrupt mode 2 - a technique that is common in Spectrum games but rather unusual in CPC games. (I'll leave the technical details to someone else to explain better than me.) Shock, horror, did Infogrames release a Speccy port?! :o

As for the original version not working properly on a real CPC - yes, this is related to the copy protection. If the copy protection check fails (and the game therefore thinks you are running a pirated copy), it speeds up the countdown timer and gives you only one life, so you get shot and die very quickly. I thought it was quite an amusing way to send a message to software pirates! It may be that CPCDiskXP can't transfer the original DSK file correctly.
Title: Re: Prohibition prohibited!!
Post by: Joseman on 00:06, 21 July 15
Note that the game does not work on Plus machines. :( This seems to be because it uses interrupt mode 2...

Don't say it very high! here are too much Plus fans!!  ;D
Title: Re: Prohibition prohibited!!
Post by: andycadley on 03:29, 21 July 15
Weird, because the Plus machines have a much more predictable IM2 than CPCs or Spectrums (Speccy coders only use it because its the only available option if you aren't using ROM routines)

I can only assume it's using a partial jump table and assuming the values that will end up on the bus. Which are mostly predictable on other machines, assuming no peripherals upset things!
Title: Re: Prohibition prohibited!!
Post by: Axelay on 12:03, 21 July 15
Shock, horror, did Infogrames release a Speccy port?! :o




Impossible, Prohibition is a good game! ;)  More seriously, it's using hardware scrolling and the 128k version double buffers the screen, so it doesnt seem too likely to me.
Title: Re: Prohibition prohibited!!
Post by: Lazy Dude on 17:17, 21 July 15
Exiting times!
right, I will be "testing" this out tonight.
Title: Re: Prohibition prohibited!!
Post by: TFM on 18:13, 21 July 15
... because it uses interrupt mode 2 - a technique that is common in Spectrum games but rather unusual in CPC games.


Unusual on spectrum ports maybe, but more often used as you think on original CPC games imho. [nb]I use IM 2 for all my games for well reasons.  ;) [/nb]  :)

Title: Re: Prohibition prohibited!!
Post by: Lazy Dude on 22:42, 21 July 15
ok I have another issue with this game....................


I am still as crap as I used to be!!!  :P

Many thanks @Nich (http://www.cpcwiki.eu/forum/index.php?action=profile;u=53) for taking the time to post up a sorted version.
Title: Re: Prohibition prohibited!!
Post by: Nich on 23:02, 21 July 15
Impossible, Prohibition is a good game! ;)  More seriously, it's using hardware scrolling and the 128k version double buffers the screen, so it doesnt seem too likely to me.
After I wrote my comment, I looked up the game on World of Spectrum (http://www.worldofspectrum.org/infoseekid.cgi?id=0003898) and it was written by Pennsoft, so it must have been converted from the CPC to the Spectrum. I tested it on a Spectrum emulator and the conversion is awful! The scrolling is incredibly slow and jerky!

Based on this evidence, Prohibition is almost certainly not a Speccy port.
Title: Re: Prohibition prohibited!!
Post by: Gryzor on 20:44, 17 August 15
Well, it's not too bad, but...


[youtube]eeHyfJhofZA[/youtube]


vs


[youtube]Ryp3I0qAj2M[/youtube]


Yeah; no comparison.
Title: Re: Prohibition prohibited!!
Post by: alex76gr on 22:00, 17 August 15
CPC version of Prohibition is nearly as good as the Atari ST version!
Title: Re: Prohibition prohibited!!
Post by: Singaja on 22:04, 17 August 15
One of favourite games of my childhood. Interestingly I recall I had a version which was launched with |cpm. The cat did display some flashing garbage instead of normal file list. Probably it was some crack to counter the copy protection.
Title: Re: Prohibition prohibited!!
Post by: TFM on 22:24, 17 August 15
One of favourite games of my childhood. Interestingly I recall I had a version which was launched with |cpm. The cat did display some flashing garbage instead of normal file list. Probably it was some crack to counter the copy protection.


Haha! No, if it was started with !CPM then it was one of the few originals you had back the day. Or a well made copy using Discology, MaterCopy or so.

Title: Re: Prohibition prohibited!!
Post by: Singaja on 22:41, 17 August 15

Haha! No, if it was started with !CPM then it was one of the few originals you had back the day. Or a well made copy using Discology, MaterCopy or so.


I'm sure it was not an original, back in the day there was no games software legal distribution in Poland. Which isn't particularly surprising since a game would probably cost something like half a wage even if one had real $. I recall seeing Discology as a kid for copying stuff, so that's the most likely candidate. But I remember the copy protection on Robocop was so good (or bad in a pissing off sense :P ) even Discology couldn't handle it, or maybe my bro was doing something wrong. haha, fun times
Title: Re: Prohibition prohibited!!
Post by: TFM on 17:45, 18 August 15
Yes, right! :)  Remember couple of games which got started with !CPM, it was always especially 'honorable' to crack such a candidate. [nb]What I of course never did, and at court they couldn't prove that I did it.[/nb]
Title: Re: Prohibition prohibited!!
Post by: Singaja on 18:37, 18 August 15
Yes, right! :)  Remember couple of games which got started with !CPM, it was always especially 'honorable' to crack such a candidate. [nb]What I of course never did, and at court they couldn't prove that I did it.[/nb]
I'm really into reverse engineering myself (but started waaay later around 2005 for Win stuff at the beginning). So you had access to some disassembler on the Amstrad? [For educational purposes only of course 8) ].
Title: Re: Prohibition prohibited!!
Post by: Gryzor on 19:51, 18 August 15
I had a copy of North Star that started with |CPM. Always baffled me.
Title: Re: Prohibition prohibited!!
Post by: TFM on 20:05, 18 August 15
I'm really into reverse engineering myself (but started waaay later around 2005 for Win stuff at the beginning). So you had access to some disassembler on the Amstrad? [For educational purposes only of course 8) ].


One day I got MAXAM on ROM and an used EPROM card from Dobbertin. This opened a whole new world.  :)
Doing stuff for Windows... respect, never tried that. The amount of data is just.. too big. I like KBs, all that MBs.... oh wait today programs are GB big... Well, too big for me.  ;)
Title: Re: Prohibition prohibited!!
Post by: Singaja on 20:47, 18 August 15
Doing stuff for Windows... respect, never tried that. The amount of data is just.. too big. I like KBs, all that MBs.... oh wait today programs are GB big... Well, too big for me.  ;)
Regarding present day RE an absolute must see is a disassembler flagship called IDA (interactive dissasembler pro). It's pretty expensive but you can get a freeware version that can handle 32bit win binaries. It speeds up the analysis process by a wow factor. Really worth checking out.
Title: Re: Prohibition prohibited!!
Post by: TFM on 20:50, 18 August 15
Need that for CPC!  ;)
Title: Re: Prohibition prohibited!!
Post by: Singaja on 21:17, 18 August 15
Need that for CPC!  ;)
IDA is not that super useful on CPC memory dumps to be honest (I used whole Ram dumps , because that seemed to be most convenient) since you cannot debug Z80 with it. WinApe has a debugger with breakpoints, ability to mark memory as data vs code, IDA shines only on cross references and data references, but still you need to manually mark memory as code, it sux. I guess there are lots of free disassemblers that can analyse z80 memory dump for cross references and data references. If only WinApe had slightly better UI for reverse engineering and maybe some plugin/extension support that would be a perfect solution, it still is an awesome tool for the job. I personally would love an option to make notes on the code, I tend to juggle winape vs notepad. Btw not to make an impression IDA actually sux, it's the one, but for more advanced binaries where you have system calls , dynamic libraries, imports/exports and all this kind of stuff.
Title: Re: Prohibition prohibited!!
Post by: arnoldemu on 11:03, 19 August 15
One of favourite games of my childhood. Interestingly I recall I had a version which was launched with |cpm. The cat did display some flashing garbage instead of normal file list. Probably it was some crack to counter the copy protection.
I have seen the garbage when CATing a disc. It can be normal.

|CPM loads the first sector from track 0 on the "reserved" tracks.
For SYSTEM discs, track 0 and 1 are "reserved" for system. Track 2 is directory.

To get more on a disc, |CPM was used and the rest of the disc filled with data. If you typed CAT you saw garbage because the cpc tried to display the data.
Title: Re: Prohibition prohibited!!
Post by: arnoldemu on 11:05, 19 August 15
Yes, right! :)  Remember couple of games which got started with !CPM, it was always especially 'honorable' to crack such a candidate. [nb]What I of course never did, and at court they couldn't prove that I did it.[/nb]
It was?

I always felt that cracking the late speedlocks was more honorable because of the crazy 8KB sectors (on disc) and the 100's of deprotection codes.

Also, cracking a multi-load correctly so it could be file copied was always something good if done right.

Title: Re: Prohibition prohibited!!
Post by: CraigsBar on 11:10, 19 August 15
It was?

I always felt that cracking the late speedlocks was more honorable because of the crazy 8KB sectors (on disc) and the 100's of deprotection codes.

Also, cracking a multi-load correctly so it could be file copied was always something good if done right.
And I was just grateful to you all.
Title: Re: Prohibition prohibited!!
Post by: TFM on 03:04, 20 August 15
No, no, we're just discussing in theory.  ;D
Title: Re: Prohibition prohibited!!
Post by: Johnny Olsen on 15:22, 22 August 15
It was often, more fun to crack  the protection than to play the game.