Joined: 10/11/2008
Posts: 64
Location: Kajaani, Finland
http://www.virtualbox.org/ Wouldn't it be easy to add TAS abilities to Virtualbox? There is an OSE (open source edition) version avaible, only thing it misses is the USB support but we don't need it on TASing? It already runs on almost every operating system avaible, so no need much porting.
Joined: 8/27/2006
Posts: 883
It's much more difficult that it looks. The emulator must be frame based, and must emulate the OS the same way on every run. If the computer lag, it might not do the same behavior. In that way, it would be impossible to TAS on it. And there's a lot of work to do. It's not that easy. You have to record input, play back input, savestate and loadstate (which would be pretty big, you have to copy the entire RAM in a file. Something like 512megs.) It's pretty difficult but I guess someone with enought knowledge could look at that.
Joined: 4/11/2010
Posts: 16
crysis sandbox: "Fixed_time_step 0.0333333333" this makes the sandbox act in 30 FPS in realtime this should be definitely possible, to be programmed. and than, for a big Hard Drive, there should be a way to make save states - 1 image into ram and the rest to the big HDD. it would be slow, but it's somehow possible. you maybe know the trialversion of some programs can't be patched to full, but if you make an EXE to the folder and start it, it's patched for this time. it has it's commands an THEN loads the original exe. the running program is changed. you understand, what i mean?
Editor, Player (44)
Joined: 7/11/2010
Posts: 1029
dwangoAC and I have been using VirtualBox to help us TAS NetHack. (Note that this incredibly far from sync-stable; it's just that NetHack syncs extremely well, regardless of pretty much any timing differences, so all we really care about is savestates, which VirtualBox has already.) It turns out that disk access (to the host computer's disk, to save savestates) is not really an issue because loadstating is CPU-bound (taking a few seconds, but it's not massively annoying; it takes about as long to loadstate as JPC-RR does but runs much faster after that). Due to the way VirtualBox works, though, I'm not convinced that any typical TAS features - frame advance, loadstate, savestate, etc - can be done without at least slight desync issues. For instance, whenever we loadstate in NetHack, it takes a while for the network interface to come back up; NetHack doesn't care at all, but other games might, if only because it would change lag properties slightly. In general, I'm far from convinced that mere virtualisation, as opposed to emulation, can ever capture the entire state of the system properly.