-=> On 08-09-22 00:30, Ryan Fantus wrote to fusion <=-
fu> another neat thing is each ntvdm gets it's own "640k" of ram, it's own
fu> EMS/XMS, etc.. it's really the scaffolding of the single-pc multinode
fu> bbs.
RF> Wow, I had no idea. That's pretty neat. Honestly, I use Windows 7 32
RF> bit for my doorgame host and it works astonishingly well. No slowdowns
RF> or any other apparent issues. Only some games like Yankee Trader don't
RF> work; everything else seems to hum along as expected.
That's the magic of virtual 8086 mode. Same happened with DESQview on a 386,
every session got its own 60k (less any OS/TSR overhead loaded before DV). And
OS/2 really made good use of virtual 8086 mode with its DOS subsystem - the
"better DOS than DOS".
fu> it's neat stuff. bit of a shame the 16bit mode is not accessable from
fu> 64bit oses.. but we're lucky it works in 32bit mode. in theory it should
fu> be faster than the ntvdm64 one, but with modern cpus i don't know if you
fu> could measure that difference anymore
As I said in another message, I'm sure I read it's possible to spin up a DOS VM
in 64 bit mode, by using the hardware virtualisation capabilities of modern
AMD64 CPUs, which would result in similar functionality.
... Any safety factor set as a result of practical experience will be exceeded
=== MultiMail/Win v0.52
--- SBBSecho 3.10-Linux
* Origin: Freeway BBS Bendigo,Australia freeway.apana.org.au (3:633/410)
■ Synchronet ■ Vertrauen ■ Home of Synchronet ■ [vert/cvs/bbs].synchro.net
|