Continuing the thread "HIMEM vs. FDXMS" started by Eric Auer: JAS>> If I use XMS but not EMS, I can save some bytes in UMB (real-mode UMB) by JAS>> using FDXMS instead of HIMEM...
EA>How big is that difference at the moment? 70 (hex) paragraphs for FDXMS.SYS v0.94 against 9E paragraphs for HIMEM.EXE that came in EMMX203.zip, that is, 736 (decimal) bytes. Quite small,indeed, but if the UMB space is one paragraph less than required by some driver, all of it will be loaded low. EA>HIMEM supports all sizes of RAM already, but is limited to 386 and newer CPU. EA>For FD*XMS*, you have one "up to 64MB" version and one "unlimited" version, EA>and the "up to 64MB" version is smaller on disk and in RAM. You also have a EA>third version, FDXMS286. This works on 286 CPU and is limited to 64 MB (on EA>286 even 16 MB) RAM. Yes,I knew it. I think this is a good feature of FDXMS. EA>PS: Supporting memory pool sharing means that you have to follow the EA>MS style handle table data format in the "up to 4 GB" variant. Both EA>FD*XMS* family and the Deskwork.de variant of FD HIMEM save some DOS EA>RAM by not supporting memory pool sharing that way. You mean: 1)the size difference is all in the support for pool sharing ? 2)It shall not be possible to have pool sharing in a "up to 64 MB" XMS driver ? I am somewhat curious about the speed difference between these drivers,but could not yet find a way to measure it, not even if there is any. JAS ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
