DOS ain't dead - IRQ ISR IDT [5] RM ISR vs PM ISR

IRQ ISR IDT [5] RM ISR vs PM ISR (DOSX)

posted by Steve , US, 24.08.2007, 01:11

> > > Plus, the original IBM PC was an 8088 and had an 8-bit one (vs. the
> > > 8086's 16-bit one, twice as fast).
> >
> > 8088 is 8-bit internal and external. 8086 is 16-bit internal and 8-bit
> > external - designed to retain adaptability to older mainboards (like
> 386SX
> > later). The 80286 introduced full 16/16.
>
> That's wrong. The 8086 already is a 16/16-bit CPU. The 8088 is limited to
> an 8-bit external data bus.

I should have checked the old data, rather than depend on my failing mamory of antique CPUs:

*8080* is 8-bit internal and external. 8088 is indeed 16/8, and 8086 (older than 8088 but used by IBM later), not 80286, introduced full 16/16.

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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