DOS ain't dead

Using Dos for Real Time applications -> CLI (Developers)

posted by Damien, 27.12.2012, 23:23

> > Most likely it's the timer interrupt called every cca 18.2 ms (!!!) and
> > eating more time than usual cca every 1 second.
> >
> > > Is this avoidable ?
> >
> >
> >   CLI
> >
>
> Yes the most of time can take BIOS/DOS interrupts. But even if you CLI,
> there will occur some SMM interrupts that are handled by SMI handler and
> cannot be disabled (this is transparrent and running behind all OS). BIOS
> writers should make this routines as fast as possible but it still may take
> some us or maybe tens of us? It also depends on hardware config and BIOS.
> If you need some microsecond precision timing I rather suggest to connect
> some external microcontroller to do this job.

Hello,

Concerning CLI I don't really know how to do it, I guess it's inline assembler in my C-code ? Also my problem is that I don't want to inhibit all interrupts at the same time but one by one, to see which one is the origin of this "long" 400us task...

Moreover, I have tested my little "loop program" on another computer, older. And the surprise is that this 400usec task does not happen. There is indeed some fluctuation, but all the loops take less that 50usec.
To sum up, this phenomenon depends on hardware used, or maybe bios options...

Complete thread:

• Using Dos for Real Time applications - Damien, 23.12.2012, 18:41 (Developers)
  • Using Dos for Real Time applications -> CLI - DOS386, 24.12.2012, 09:39
    • Using Dos for Real Time applications -> CLI - RayeR, 24.12.2012, 15:13
      • Using Dos for Real Time applications -> CLI - Damien, 26.12.2012, 12:50
      • Using Dos for Real Time applications -> CLI - Damien, 27.12.2012, 23:23
        • Using Dos for Real Time applications -> CLI - RayeR, 28.12.2012, 01:32
          • Using Dos for Real Time applications -> CLI - Damien, 02.01.2013, 13:20
            • Using Dos for Real Time applications -> CLI - Laaca, 02.01.2013, 21:02
              • Using Dos for Real Time applications -> CLI - RayeR, 02.01.2013, 23:22
              • Using Dos for Real Time applications -> CLI - Damien, 05.01.2013, 14:10
                • Using Dos for Real Time applications -> CLI - RayeR, 06.01.2013, 21:43
                  • Using Dos for Real Time applications -> CLI - Damien, 09.01.2013, 13:12
                    • Using Dos for Real Time applications -> CLI - RayeR, 09.01.2013, 13:52
                      • Using Dos for Real Time applications -> CLI - Arjay, 09.01.2013, 23:40