FreeDOS help system (hhstndrd 1.0.8 en)[fdxms]

Command: fdxms.sys

FDXMS.SYS is an extended memory driver for FreeDOS. FDXMS.SYS is for 386+ computers. Fdxms286 is for 286 computers. FDXMS.SYS has to be loaded in CONFIG.SYS / FDCONFIG.SYS. FDXMS.SYS is out of date. You should use HIMEMX or JEMMEX instead.


DEVICE=[drive][path]\fdxms.sys [options] drive The drive letter, e.g. C: path The directory, e.g. \example\


NUMHANDLES= Sets the number of XMS handles. Default is 32. Minimum is two (not much use of XMS without any handles!) and maximum is currently 1024. Each handle takes 5 bytes (FDXMS.SYS) or 9 bytes (FDXXMS.SYS). BIOS Makes FDXMS always call the BIOS through INT15 instead of using its own protected mode switching. PS Changes to the particular A20 handling necessary on PS/2 machines. GEODE Removes delays while changing the A20 line. Reported to help FDXMS to work on National Semiconductor's Geode GX1 processor. DELAY= Number of calls to the delay routine after changing the A20 line. If you receive the error message "Unable to switch A20 address line", try setting it to a big value (say 4000) and see if it helps. Then fine tune it as you want as low a value as possible for speed. Default is 1. Maximum is 65535 and 0 maps to 65536.


FDXMS.SYS has to be loaded in CONFIG.SYS / FDCONFIG.SYS.


IN CONFIG.SYS / FDCONFIG.SYS: device=c:\fdos\fdxms.sys

See also:

config.sys devload (emm386) fdconfig.sys (fdxms286) (himem) himemx jemm386 jemmex xmgr ------------------------------------------------------------------------------ Copyright (C) 2003 Martin Stromberg, updated 2011 by W. Spiegl. This file is derived from the FreeDOS Spec Command HOWTO. See the file H2Cpying for copying conditions.