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Convert notes into blockquotes

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James Gregory 2013-12-31 11:06:31 +11:00
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@ -129,6 +129,12 @@ in, and simply pass pointers to these structures to the low level,
rather than passing many separate parameters, as is now the case. I've
used separate parameters for simplicity and flexibility.
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![](images/i.jpg) *Be aware that as nifty as Mode X hardware-assisted masked copying is, whether or not it's actually faster than software-only masked or transparent copying depends upon the processor and the video adapter. The advantage of Mode X masked copying is the 32-bit parallelism; the disadvantages are the need to read display memory and the need to perform an **OUT** for every four pixels. (**OUT** is a slow 486/Pentium instruction, and most VGAs respond to **OUT**s much more slowly than to display memory writes.)*
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> ![](images/i.jpg)
> Be aware that as nifty as Mode X hardware-assisted masked copying is,
> whether or not it's actually faster than software-only masked or
> transparent copying depends upon the processor and the video adapter.
> The advantage of Mode X masked copying is the 32-bit parallelism; the
> disadvantages are the need to read display memory and the need to
> perform an **OUT** for every four pixels. (**OUT** is a slow 486/Pentium
> instruction, and most VGAs respond to **OUT**s much more slowly than to
> display memory writes.)