DOS ain't dead - IRQ ISR IDT [2]

IRQ ISR IDT [2] (DOSX)

posted by Japheth , Germany (South), 14.08.2007, 22:24

> > If the PIC is not reprogrammed, IRQ 0 and Exception 08 use the very same
> interrupt.
>
> Is this true under HDPMI32 ? Does HDPMI32 poll the PIT to distinguish them
> ?

No. it uses the value of ESP to determine if it's an IRQ or an exception.

> And what should I write to the 8 bytes of the IDT entry 8 ? Can I pick
> them from there (same/different entry ?), hack the address, maybe change
> some of the Ring stuff (???) to get the most straightforward
> "asynchronous" subroutine call ?

I think this is an excellent exercise for learning low-level programming, so I don't want to spoil this pleasure by telling how it is done. :-D

---
MS-DOS forever!

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Complete thread:

IRQ ISR IDT - DOS386, 13.08.2007, 07:05 (DOSX)
- IRQ ISR IDT - Japheth, 13.08.2007, 08:18
  - IRQ ISR IDT [2] - DOS386, 13.08.2007, 08:34
    - IRQ ISR IDT [2] - Japheth, 14.08.2007, 22:24
      - IRQ ISR IDT [3] Very weeeird results - DOS386, 16.08.2007, 10:28
        IRQ ISR IDT [3] Very weeeird results - Japheth, 16.08.2007, 14:24
        IRQ ISR IDT [4] Missed the point - DOS386, 17.08.2007, 00:58
        IRQ ISR IDT [4] Missed the point - Japheth, 17.08.2007, 10:50
        IRQ ISR IDT [5] RM ISR vs PM ISR - DOS386, 19.08.2007, 07:46
        IRQ ISR IDT [5] RM ISR vs PM ISR - Rugxulo, 21.08.2007, 03:16
        IRQ ISR IDT [5] RM ISR vs PM ISR - Japheth, 21.08.2007, 08:28
        IRQ ISR IDT [5] RM ISR vs PM ISR - Rugxulo, 22.08.2007, 00:13
        IRQ ISR IDT [5] RM ISR vs PM ISR - Steve, 23.08.2007, 13:42
        IRQ ISR IDT [5] RM ISR vs PM ISR - rr, 23.08.2007, 15:25
        IRQ ISR IDT [5] RM ISR vs PM ISR - Steve, 24.08.2007, 01:11