Flipping vs. Swapping Screens in CodeView

 Last reviewed: July 17, 1997
Article ID: Q24201
2.20 3.00 3.11 4.01 4.05 4.10 | 2.20 3.00 3.11 3.12 3.50 
MS-DOS                        | OS/2
kbtool

The information in this article applies to:

  • Microsoft CodeView for MS-DOS, versions 2.2, 3.0, 3.11, 4.0, 4.01, 4.05, and 4.1
  • Microsoft CodeView for OS/2, versions 2.2, 3.0, 3.11, 3.12, and 3.5

Flipping and swapping are both ways of maintaining two alternate screens for display on one monitor. The difference is in the way the task is accomplished.

When swapping is selected, CodeView allocates a 16K buffer (a 4K buffer for a monochrome adapter) to hold the alternate screen. When the other screen is required, CodeView swaps the screen into the display buffer and places the other screen into the storage buffer. Swapping takes memory and time but it does not have the limitations of flipping.

Flipping uses the video-display pages of the graphics adapter to store each screen of text. When the alternate screen is required, the other page is selected. Flipping is much faster than swapping and does not require the 16K buffer. However, it cannot be used with a monochrome adapter, or with programs that display graphics or use the video pages.

Additional reference words: kbinf 2.20 3.00 3.50 4.00 4.10
KBCategory: kbtool
KBSubcategory: CvwIss
Keywords : kb16bitonly

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Last reviewed: July 17, 1997
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