Just noticed that the recently added 'Q*Bert' game will run with OS-B only and I believe this is due to so-called illegal jumps into the OS.
I remember coming across a few games like this (an Asteroids clone and Pogo Joe spring to mind) which were easily fixed to run fine on XL machines by simply changing all the old JSR's into the OS with their new XL positions. This was easily done if you had a copy of 'Mapping the Atari (revised edition)'. Of course the games wouldn't run on the old 400/800 machines anymore but I wasn't aware of anyone who owned one of these anyway. I suppose it'd be possible to have a little sub-routine you jumped to which could check the machine you had and JSR accordingly (the menu created by Rob.C Menu Maker does something like this) but that seems too much like hard work!
Anyway, my point it that someone with a decent disk sector editor (Bob's Sector Editor was my favourite) and 'Mapping the Atari RE' could create an XL version of this game in a short amount of time! My copy of the book is in the loft!
Illegal jumps into the OS.
Moderators: Atari Frog, Andre
Re: Illegal jumps into the OS.
Hello John,
Since many people who download dumps use emulators (where OSes can easily be switched) every game can be enjoyed, at least in principle
For this reason it takes precedence to upload dumps that are missing in the database instead of patching those already available. Providing dumps is hard enough since many dumps floating around in the net have some serious bugs or are crippled (missing intro etc.) and thus we have to convert original disks or tapes to atr-format by ourselves. And, I am quite sure you know what this means 
If you or other enthusiasts would patch games from our site for use with different OSes then this would be great. But these patches must not alter the audiovisual content or gameplay of the respective game. Of course you would be fully credited in the comment section of the respective game
that's correct and any help is appreciated.John E. wrote: Just noticed that the recently added 'Q*Bert' game will run with OS-B only ... which were easily fixed to run fine on XL machines by simply changing all the old JSR's into the OS with their new XL positions.
That would be a good way to go.I suppose it'd be possible to have a little sub-routine you jumped to which could check the machine you had and JSR accordingly (the menu created by Rob.C Menu Maker does something like this)
Since many people who download dumps use emulators (where OSes can easily be switched) every game can be enjoyed, at least in principle
For this reason it takes precedence to upload dumps that are missing in the database instead of patching those already available. Providing dumps is hard enough since many dumps floating around in the net have some serious bugs or are crippled (missing intro etc.) and thus we have to convert original disks or tapes to atr-format by ourselves. And, I am quite sure you know what this means If you or other enthusiasts would patch games from our site for use with different OSes then this would be great. But these patches must not alter the audiovisual content or gameplay of the respective game. Of course you would be fully credited in the comment section of the respective game