X-Authentication-Warning: delorie.com: mailnull set sender to djgpp-bounces using -f From: "Charles Sandmann" Newsgroups: comp.os.msdos.djgpp Subject: Re: problem with 8254 (Timer) Date: Mon, 7 Jan 2002 17:17:37 Organization: Aspen Technology, Inc. Lines: 14 Message-ID: <3c39d831.sandmann@clio.rice.edu> References: NNTP-Posting-Host: dcloan.hou.aspentech.com X-Trace: selma.aspentech.com 1010445817 4285 10.32.115.107 (7 Jan 2002 23:23:37 GMT) X-Complaints-To: postmaster AT aspentech DOT com NNTP-Posting-Date: 7 Jan 2002 23:23:37 GMT X-NewsEditor: ED-1.5.8 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com > In my old PC this program works correctly while in my Celeron 500Mz it does > not work in DOS (real mode + CWSDPMI). It miss 350us every a lot, without > regularity. Seems like an interrupt is executed but it is impossible because > i have disabled them whith a CLI istruction. This problem can be caused > from NMI or from the CWSDPMI ???? Help me! CWSDPMI doesn't issue any periodic interrupts (it's quite happy being out of the way and turned off if you don't need it). If you have issued a CLI (and not done any operations which might have enabled interrupts - double check this) then I suspect it's some NMI from your hardware. You could try installing a PM NMI handler which just does a IRET and see if that helps; or try using the ring 0 version with an IRET (or PMODE 1.3). If an NMI happens it would be passed to real mode, and all of that could be quite slow.