Examples of cracked versions of games

[beamrider]

This came up on Facebook, so I thought I'd ask here.

Does anyone have examples of Vic-20 games that were 'cracked' from back in the day.

As I recall, the limit of this on the Vic-20 was altered title screens and REM statements of the form Cracked by XXXX. It wasn't until the C64/Amiga that scrollers etc were introduced.

[orion70]

I guess some examples may come from the Italian universe of pirated newsstand cassettes, which were full of modified versions of commercial games. Instructions and in-game text were often modified (e.g. to hide the original game title) and/or (poorly) translated in Italian. I cannot remember if some of these had proper cracktros, but I don't think so, as they were presented as if they were originals

Have a look here: https://www.edicola8bit.com/giochi.php?console=vic20

[Noizer]

[...] anyone have examples of Vic-20 games that were 'cracked' from back in the day.[...]

viewtopic.php?f=10&t=797

Look closer at some game intros from Miklos, maybe in ten years. He is updating the past now.

[orion70]

"updating the past" is a great motto, we can extend it to the whole forum

[Noizer]

Back to future missing last part (happy NY MJF) we‘r trying to make our own past right back, at least. Mr. Anderson... oh ... Orion ... Sorry galaxy king

[Mike]

What Miklós does is producing trained/improved versions of games, but not cracking them. In most cases, working copies/dumps of the games had been available long ago already, and on the VIC-20, they did not have any noteworthy copy protection that needed to be removed.

[Noizer]

What Miklós does is producing trained/improved versions of games, but not cracking them. In most cases, working copies/dumps of the games had been available long ago already, and on the VIC-20, they did not have any noteworthy copy protection that needed to be removed.

I know... time of burst nibbler and reliving the copies are long time ago. Nevertheless is Milos doing it very well.

[beamrider]

I think there has been some level of cracking of Vic games.

Take for instance JetPac as an example. This is available on finet as a simple prg with a "10 SYS4624 " when you list it. However when you examine the original tape image, it's a two-parter with the following loader.

Code: Select all

5 print"S"
10 print"]]]]]]]]qqqqq
qqjetpac"
20 print"qqqqqqq"
30 print" copyright 19
83 a.c.g"
40 print"q all rights
reserved"
50 for n=1to30
60 reada:poke 5375+n,a
:next
70 sys5376
80 data169,240,133,172
,169,31,133,171
90 data 169,01,133,184
,133,186,169,00
100 data 133,185,133,1
83,162,240
110 data 160,31,32,66,
245,76,29,32

When you load the second part unsurprisingly there is no basic stub.

So someone has at least made it convenient to copy to disk with a standard load/save command, even if the copy protection was minimal it would stump the average game player of the era I suspect.

[Mike]

Copying multi-part tape programs to disk almost always amounts to some adaptation, at least replacing a simple "POKE631,131:POKE198,1" by something more elaborate that takes the last used device number into account. Or fixing the joystick decode routines (even in the case of tape one-filers). Nothing of that counts as removing any kind of copy protection.

... it would stump the average game player of the era I suspect.

The school kids had all the time for this. Once they had learnt the basics, transferring games to another medium was a stroll in the park.

[beamrider]

Well I guess it depends on how you define copy protection.

I would say that anything you can't load/save using the built-in commands counts as such and as I recall from trying back in the day, many of the Vic games can't be copied that way.

[Mike]

Well I guess it depends on how you define copy protection.

On tape, the absolute minimum of what I consider copy protected:

• forced autostart (even if just LOAD+[RETURN] was entered!),
• a turbo tape routine,
• STOP and STOP/RESTORE disabled.

The autostart ensures that STOP and STOP/RESTORE are forcibly disabled. Even if that (on the VIC-20) does not prevent a hardware reset, that gives the program enough time to erase important initialisation routines right after start-up, so a simple memory dump after reset is not sufficient to recover the game.

A turbo tape forces the use of the turbo routine to load the game into memory in first place. Getting the turbo tape routine into memory without it autostarting then is the first step in actually cracking such a game: you search for the JMP instruction into the game code, change it to point to an own memory dump routine instead and only then actually start the turbo tape routine. Once the game has been loaded from tape, the relevant parts of the memory are then dumped to disk. You use a disk loader to load that dump or one-file it and hey, presto!

One notorious example I remember was Hektik on the 264 machines (see here): not only the tape sported all of the aforementioned protection measures, it actually was loaded in a tandem procedure (4 parts) each of which transferred control to a new turbo tape routine as the next part was loaded and worst, the last part was loaded into a part of memory where normally the screen RAM was located! That meant whatever I prepared as dump routine had to survive that tandem load procedure and just kick in after the last part was loaded and before the main game code was executed ...


That being said, even if such tape games could still be copied by simply dubbing them, that is an analog copy with the prospect to deteriorate over subsequent generations.

[beamrider]

I believe NightCrawler satisfies 2 out of 3 of those requirements and since there's little point in a turbo-loader for an unexpanded Vic game I would say it's copy protected perhaps to a lesser degree but still has features designed to deter casual copying.

[Mike]

I did a quick peek with MINIMON at a *.tap file of NightCrawler, and except that it lacks a tape turbo as you mention, it is otherwise a quite nice example. Both parts can be loaded with the L command of MINIMON without the autostart kicking in.

The first part mainly consists of a loader put into the tape buffer by means of an over-length file name, and it merely loads 4 bytes into $0300..$0303 to force the autostart. A routine at $0351 prepares a call of KERNAL LOAD at $0200(!) which finally chains to the main program at $100E ... but we're still not finished.

With the second part, its also over-length file name installs yet another routine in the tape buffer, and the main program repeatedly calls that routine, again at $0351, to decode parts of the main program!

A successful copy could omit the first part, but requires a dump of the second part with main program ($1000..$1DFF) and full tape buffer ($033C..$03FB) to disk. Easily done with the S command of MINIMON ... ... the disk loader program 'just' loads both files and then does a JMP $100E.

It is possible to create a 'mastering' program that re-creates a digital copy of the game back on tape, by writing both parts with their over-length filenames, but that requires a RAM expansion to hold both parts in higher memory, before putting each part into their place in RAM and saving from there to tape.

[Noizer]

I did a quick peek with MINIMON at a *.tap file of NightCr[...]
It is possible to create a 'mastering' program that re-creates a digital copy of...[...]

All right Mr. Anderson... Mr. Mike
We are still missing something you pretend to argument about here:
- Minimon: ???
- creating a mastering program on scratch?! I know you’re genius, let the surprise fallout

[beamrider]

Interesting, I can remember being unable to copy this back in the day hence taking a look at it. As an aside it was apparently sold by Rabbit software in the UK without licence. http://www.geocities.ws/rmelick/30.htm