From: "Chih-Hao Tsai" Newsgroups: comp.os.msdos.djgpp Subject: PCTIMER 1.4 Date: Sat, 14 Mar 1998 06:24:35 -0600 Organization: University of Illinois Lines: 44 Message-ID: <6edsu4$1a3$1@vixen.cso.uiuc.edu> NNTP-Posting-Host: archbald-15.slip.uiuc.edu To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk I am about to upload PCTIMER 1.4, the latest version of my millisecond resolution timing library to SimTel. (Within a week or so, I suppose.) The current version, PCTIMER 1.3 was released more than two years ago. Over the years it has been reported that this version does not work very well. Especially when compiled with DJGPP V2 and executed under Win95, the timer frequency will be double. So I read the latest DJGPP FAQ and found that "hardware interrupts are always passed to protected mode first, and only if unhandled are they reflected to real mode". It appears that there's no need to implement both real and protected mode handlers. So I removed the protected mode handler and tested the program again. No particular problem observed. Everything seemed to be ok. PCTIMER now also locks data and code for the real mode handler, as instructed in the FAQ. Regarding Win95, it is really not a good idea for a program to touch hardware interrupts. The Win32 Multimedia Timer API has the ability to do millisecond resolution timing, but I am not sure if RSXNT supports winmm.lib. I also included a document on using Win32 API to do regular and millisecond timing with Visual C++ 4.0 on Win95 platform. Hao -- ;; .signature -- defines a variable containing information about hao (defvar hao '((name-english "Chih-Hao Tsai") (name-chinese "˝˛§ÓŻE") (organization "Beckman Institute, UIUC") (email "hao DOT tsai AT uiuc DOT edu") (homepage "http://casper.beckman.uiuc.edu/~c-tsai4") (icq 5734422))) -- ;; .signature -- defines a variable containing information about hao (defvar hao '((name-english "Chih-Hao Tsai") (name-chinese "˝˛§ÓŻE") (organization "Beckman Institute, UIUC") (email "hao DOT tsai AT uiuc DOT edu") (homepage "http://casper.beckman.uiuc.edu/~c-tsai4") (icq 5734422)))