Also, as for reproduction instruction: Start MS-DOS and make sure to bypass CONFIG.SYS and AUTOEXEC.BAT. Then run Microsoft Diagnostics (MSD) and press M for Memory. Look at the Memory Map: areas that are available, get marked as either "potentially available" (which means EMM386 will treat them with caution and not address them unless told to) or "Option RAM", well as anything but "available". Or just load EMM386.EXE from CONFIG.SYS with a simple DEVICE=EMM386.EXE (preceded by DEVICE=HIMEM.SYS obviously) and reboot. You'll get an error message telling you that EMM386 was unable to find a page frame for EMS, and MEM will report 0 upper memory.
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1180923 Title: unused memory filled with 0x00 instead of 0xFF Status in QEMU: New Bug description: Qemu, ever since it was made (so, since 2003), has this problem in DOS (either PC-DOS or MS-DOS and partly Windows 9x) not recognizing the memory available when the memory is filled with 0x00 but when it is filled with 0xFF it gets recognized properly, where should I patch qemu to solve this memory problem? To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1180923/+subscriptions
