X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f From: Gianfranco Boggio-Togna Newsgroups: comp.os.msdos.djgpp Subject: "Protected mode not available" Date: Tue, 04 Jan 2005 18:32 +0100 Lines: 61 Message-ID: <3402a2F43rr8fU1@individual.net> X-Trace: individual.net WKjRFvB2Z/46K33Ln78QRQqzU+3P5eBX9RsLTioJ9vjjv6w28= To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com This post is somewhat OT as I have no problems with the DJGPP software (except for the minor one of not being able to run it...) but I know that among the readers of the newsgroup are some of the best experts on real/protected mode switching. A couple of years ago I decided to retire my Pentium 166 and get a newer and faster machine. I had some misgivings about the move as I wanted to retain DOS (actually Novell DOS7) as my main system, with Windows 98SE for accessing the Internet and for support of USB devices (I use XOSL to switch between the two). I asked my dealer to mount an Intel motherboard (D845GEBV2), as I thought this would offer the best level of compatibility with the original 386 architecture. In fact, after some considerable struggles (I had to install a second disk and an old PCI video card), I managed to get an almost exact replica of the configuration I had on the P166, except for one thing. I had not been aware of the existence of ACPI and I found, to my dismay, that the only way to set the system to power saving mode was to boot into Windows 98 and switch to standby. Except for this nuisance, everything went smoothly for several months. Then, all of a sudden, I started getting "Protected mode not available" messages whenever I tried to run a program compiled with DJGPP or Free Pascal. This was not a quirk of CWSDPMI, as the DPMI manager of QEMM gave the same message. Clearly the machine was not booting into real mode. Windows 3.1, however, would start and the DJGPP software would run normally in a DOS box. But something was wrong with the disk cache, with a hit rate below 20%: most of the time I run TeX (Eli Zaretskii's excellent port of Web2C) and after a few minutes the cache hit rate should get above 95% and stay there. Some weeks later I realized, quite by chance, that after a warm boot (the Norton Utilities BE REBOOT) the machine restarts in real mode. I modified CONFIG.SYS and AUTOEXEC.BAT so that I can force the warm reboot and I now have again a more or less normal system. Having to do a double boot is tiresome but I can live with it: it just means a few seconds' delay. I feel, however, rather nervous about the possibility of ACPI playing some other trick (as an old programmer, I think that allowing software to make changes to the firmware that cannot be nullified by removing power is sheer stupidity). I would like to have a way of restoring the motherboard to its original "factory" state. Reloading the BIOS would probably do the trick, but it is far too risky. The BIOS setup menu has no such option nor is there any relevant information in the motherboard documentation. To be fair, Intel states quite clearly that the board requires Microsoft Windows, in a version not earlier than 98SE. I wonder if there is any program or procedure that I might use to reset the board or, at least, to diagnose the problem more precisely. Would a recent version of Linux offer any facilities in this area? I have an old distribution (which I hardly ever use) which has apparently no support for ACPI, but I could easily upgrade it. Ideally, I would like to turn off power saving in Windows98. But for this I would need a program that can enable power saving in DOS. I have done some extensive searching and I have not come across any mention of such a program. -- Gianfranco Boggio-Togna Milano (Italy)