DragonDOS-compatible OS with workspace in high memory?
Posted: Thu Apr 29, 2021 5:17 pm
Hello everyone,
I am re-acquainting myself with the old beast, and rediscovered that many of the games, when loaded from disk (with a standard DragonDOS cartridge), cause the machine to crash. I found some software that makes it possible to "detach" DragonDOS (and its BASIC extensions) and to then EXEC the games without issues.
35 years ago, I used to save the game under FLEX and run them from DBASIC, with good compatibility.
But, if I remember correctly, most of the incompatibilities come from the memory mapping of a DOS workspace between $0600 and $0BFF and the resulting shifting of the graphic workspace. Since the DOS ROM does not occupy memory between $E000 and $E5FF, I guess it should be possible in 64K mode for a DragonDOS-compatible DOS to use that workspace. I vaguely remember some DOS used to do that, but I can't recall whether it's a Coco or a Dragon DOS.
Can someone help me? And/or is the ML source of some DragonDOS available anywhere - so I could compile my own?
Thanks
Philippe
I am re-acquainting myself with the old beast, and rediscovered that many of the games, when loaded from disk (with a standard DragonDOS cartridge), cause the machine to crash. I found some software that makes it possible to "detach" DragonDOS (and its BASIC extensions) and to then EXEC the games without issues.
35 years ago, I used to save the game under FLEX and run them from DBASIC, with good compatibility.
But, if I remember correctly, most of the incompatibilities come from the memory mapping of a DOS workspace between $0600 and $0BFF and the resulting shifting of the graphic workspace. Since the DOS ROM does not occupy memory between $E000 and $E5FF, I guess it should be possible in 64K mode for a DragonDOS-compatible DOS to use that workspace. I vaguely remember some DOS used to do that, but I can't recall whether it's a Coco or a Dragon DOS.
Can someone help me? And/or is the ML source of some DragonDOS available anywhere - so I could compile my own?
Thanks
Philippe