u know, many games doesnt provide a convenient save mechanism.
so i want to know if dosbox support or will support a function, which can capture and save the memory to file?
Nope, it doesn't. The feature would be quite nice to have, but according to the devs, it's very hard to implement "Save States" in DOSBox. Remember, we're dealing with a system that's quite complex in terms of both hard- and software.
wrote:Nope, it doesn't. The feature would be quite nice to have, but according to the devs, it's very hard to implement "Save States" in DOSBox. Remember, we're dealing with a system that's quite complex in terms of both hard- and software.
It's not very hard to implement per se, it's just that it was never designed from the start to ever be able to do this, and trying to apply it retro-actively is really, really hard, given the number of configurations supported.
JAL
It's my opinion that save-states are always problematic when storage devices (disks) are involved, because in a sense they are a sort of memory that is tied into the "state" of the system. Imagine a worst-case scenario where you take a snapshot of the system while it is in the middle of doing an install... you practically have to save the contents of the disk as part of the state in order for it to be valid when restored.
Some parts in dosbox contain recursion (pagefaults, keyboard input/tsr capturing)
and this part remains unresolved.
wrote:It's my opinion that save-states are always problematic when storage devices (disks) are involved
Yes, storage devices are an extra pain, at least when you don't tie them in with the state saving.
you take a snapshot of the system while it is in the middle of doing an install... you practically have to save the contents of the disk as part of the state in order for it to be valid when restored.
Indeed. At least, you cannot start another snapshot on the same disk.
JAL
wrote:Some parts in dosbox contain recursion (pagefaults, keyboard input/tsr capturing) and this part remains unresolved.
Very problematic areas, though if designed from the start to support state-saving, defintely not impossible. I take it currently DOSbox uses the system stack for this recursion, so I understand it is impossible to save properly.
Note: I'm not advocating DOSbox should ever attempt to do a save-state implementation. I know some of you guys get irritated when someone does, and I wouldn't inadvertently irritate you 😀.
JAL
Oh irritations aren't that bad. It was said that using an emulated dos it would
not be possible to run win3x in enhanced mode.
There are some ideas to avoid the recursions or work around it (actually the
places where removing it are already handled), like disallowing saving when
pagefaults are active.
yeh could just postpone the saving till the machine is in a state that allows it.
Another trick would be for those trouble parts, use a static workable state that you insert for the restore. If you don't need exact for some or all areas, that might get it over the hump to have a workable save state.
Feel free to try it, especially for the keyboard input and recursive command shells.
Where do you see recursive command shell use?
Whenever command.com is called from an app.
