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2f1e635b9d
Pushed all words directly interfacing with ports and memory offsets to low level layers. This saves us the need for keeping those variables in runtime memory.
17 lines
695 B
Plaintext
17 lines
695 B
Plaintext
# Z-Offset
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This LCD has a "Z-Offset" parameter, allowing to offset rows on
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the screen however we wish. This is handy because it allows us
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to scroll more efficiently. Instead of having to copy the LCD
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ram around at each linefeed (or instead of having to maintain
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an in-memory buffer), we can use this feature.
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The Z-Offet goes upwards, with wrapping. For example, if we
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have an 8 pixels high line at row 0 and if our offset is 8,
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that line will go up 8 pixels, wrapping itself to the bottom of
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the screen.
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The principle is this: The active line is always the bottom
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one. Therefore, when active row is 0, Z is FNTH+1, when row is
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1, Z is (FNTH+1)*2, When row is 8, Z is 0. (cont.)
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