Hi Alvin, > Hi Eric -- I now know what I need which is X86 Real Mode. using WATCOM C. > I plan to use FREERTOS on FREEDOS. Thanks. ALvin....
Actually DJGPP also has good functionality to measure exact timing. FreeDOS does not use much CPU no matter which mode you use - real mode or vm86 - you can also use DJGPP. However, you should to try to access files at time critical moments. Also, I found USB access to be slow, for example if you have USB mouse or keyboard with BIOS support (the BIOS makes them look like PS/2 but access is slow that way). What else could be slow? Maybe handling too many hardware interrupts in little time. You can use for example uclock() to measure time. Of course doing everything in real mode means that it is a bit faster to call DOS / BIOS interrupts and to handle hardware interrupts, but you have less RAM to access. You could "swap" some data to/from XMS which is relatively fast. Note that if you use protected mode (DJGPP or similar) you want to configure your DOS extender (CWSDPMI, Japheth HX, DPMIONE, DOS32A) to not use a swap file, as swapping is slow again. Also note: DOS is only in real mode if no EMM386 or similar protected mode based drivers are loaded :-) Eric ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
