At 08:02 AM 3/15/2004 +0200, Luchezar Georgiev wrote: >>>total(available) EMS 6(5) pages = 96(80) kByte >>I'm going to pump up the default EMS allocated by 96K for NOEMS, which should always >>leave at least a little bit for VCPI and give more for EMS internal tables with lots >>of RAM, like you have. That should make your NOEMS problem go away. > >Please "pump it up" by 144 KB, not 96 KB, for a total of 240 KB (224 KB free), >because it's possible to have up to 220 KB of UMBs by including F0000-F6FFF in the >UMBs (B0000-B7FFF = 32 KB, C8000-D0000 = 32 KB, D0000-EFFFF = 128 KB, F0000-F6FFF = >28 KB, and 32 + 32 + 128 + 28 = 220 KB total). Many BIOSes use only F7000-FFFFF as >resident space, freeing 28 KB starting at F0000. That's a well-kept BIOS secret which >I learned from the UDMA author Jack R. Ellis ;-)
UMB detection will always increase EMS by the amount of UMB's detected, so the fixed size allocation increase wouldn't affect how much other extra is there for those, it would be strictly for non-UMB use (varied internal tables and VCPI). Also, EMM386 currently only uses a multiple of 16K UMB sizes due to its EMS-based mapping origins, and it stops scanning at 0F000h. Already have a request to auto-detect VMware and stop scanning ROM's at its crash point, which is either 0e800h (VMware's own knowledgebase documented exclusion start for EMM386) or 0ec00h, where it is the actual location causing the problem for users. Problem is that VMware doesn't have an official method of detection when a DOS session is running under it, although the unofficial test is said to be reliable and has the virtue of being compact. What else might become unstable with a scanning move into the 0F000 range is unknown. I would admit that EMM386's original UMB code leaves something to be desired for advanced UMB work and squeezing out every available byte for UMB's. It also has the virtue of being simple and conservative about reclaiming memory across all the target machines, though. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Freedos-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-devel
