DOS ain't dead

And now: int 0x21 in hw interrupt handler? (Developers)

posted by myrkraverk, 18.12.2012, 20:16

> The InDOS flag is one of a few different checks you need to make to test
> whether DOS is already doing something or not. The problem is, what do you
> do if it's not safe? Your only option is to wait until it is safe, and
> that can never happen until you exit the IRQ handler. So, you need to have
> another process to download the data anyway, so you might as well just do
> it that way from the beginning.

If I write the app in a way that it never calls int 0x21 while my IRQ handler
is active, am I safe? Are there other interrupts I must also not call?
BIOS, something else?

At the moment, I'm not sure I'll do any kind of visual feedback, but I can do
that by writing directly to the video memory.

Complete thread:

• Basics of interrupt chaining? - myrkraverk, 13.12.2012, 19:39 (Developers)
  • Basics of interrupt chaining? - myrkraverk, 13.12.2012, 20:19
  • Basics of interrupt chaining? - Japheth, 13.12.2012, 21:31
    • And now: int 0x21 in hw interrupt handler? - myrkraverk, 14.12.2012, 02:58
      • And now: int 0x21 in hw interrupt handler? - Japheth, 14.12.2012, 06:10
      • And now: int 0x21 in hw interrupt handler? - tom, 14.12.2012, 18:25
      • And now: int 0x21 in hw interrupt handler? - bretjohn, 15.12.2012, 01:29
        • And now: int 0x21 in hw interrupt handler? - myrkraverk, 15.12.2012, 15:52
          • And now: int 0x21 in hw interrupt handler? - bretjohn, 17.12.2012, 18:08
            • And now: int 0x21 in hw interrupt handler? - myrkraverk, 18.12.2012, 20:16
              • And now: int 0x21 in hw interrupt handler? - tom, 19.12.2012, 15:54
  • Basics of interrupt chaining? - bretjohn, 14.12.2012, 19:43