Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

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    Video mode and adapter combinations not listed above support one display
    page (for example, a Monochrome Adapter in mode 7).
 
    Switching between pages does not affect their contents. In addition,
    text can be written to any video page with Int 10H Functions 02H, 09H,
    and 0AH, regardless of the page currently being displayed.
 
    On the PCjr, the CPU page determines the part of the physical memory
    region 00000H-1FFFFH that will be hardware mapped onto 16 KB of memory
    beginning at segment B800H. The CRT page determines the starting address
    of the physical memory used by the video controller to refresh the dis-
    play. Smooth animation effects can be achieved by manipulation of these
    registers. Programs that write directly to the B800H segment can reach
    only the first 16 KB of the video-refresh buffer. Programs requiring
    direct access to the entire 32 KB buffer in modes 09H and 0AH can obtain
    the current CRT page from the ROM BIOS variable PAGDAT at 0040:008AH.
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