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19. Real Mode Segmented Model

  • Real mode segmented model was mainstream programming model throughout the MS-DOS era.

  • Used when Windows 9x machine is booted into MS-DOS mode.

  • Good choice to write code to run under MS-DOS.

  • Program has access to 1MB of memory.

  • The CPU handles transformations of segment:offset combinations into a full 20-bit address.

  • CS always points to the current code segment

  •   The real mode segmented model

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