guides:text_mode
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guides:text_mode [2020-08-28 23:02] omolini |
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| Ever wondered why VGA text mode had at times, ugly looking text mode graphics? Most all VGA boards by default displayed text at a larger font glyph size of 9x16 pixels, while remaining compatible with the earlier font size at 8x14 pixels. While this added clarity to text by creating a higher resolution display, it was a compromise to keep compatibility with older hardware. | Ever wondered why VGA text mode had at times, ugly looking text mode graphics? Most all VGA boards by default displayed text at a larger font glyph size of 9x16 pixels, while remaining compatible with the earlier font size at 8x14 pixels. While this added clarity to text by creating a higher resolution display, it was a compromise to keep compatibility with older hardware. | ||
| - | When VGA text mode was being designed, the designers were able to increase the font height from 14 to 16 pixels, however they were unable add to the width without breaking compatibility. So instead they decided to increase the width by adding a blank column. In some cases, it did make sense to separate text with space to make it more readable, however it also made some text mode graphical applications look bad. Here's an example of what a wall of 50% gradient characters looks like in VGA: | + | When designers took to increase the resolution of the VGA as compared to the earlier EGA standard, they had to come up with a new higher definition text mode as well. To do this, they increased the font height from 14 to 16 pixels to match the new higher resolution of the display while keeping the amount of rows and columns of text the same for compatibility. They needed to add a ninth column to increase the width, but this was impossible without breaking compatibility. So instead they decided to increase the width by adding a column that contained no font data in ROM, so in essence it was blank. In some cases, it did make sense to separate text with space to make it more readable, however it also made some text mode graphical applications look weird. Here's an example of what a wall of 50% gradient characters looks like in VGA: |
| {{ :guides:pics:text_mode_setup_vga.jpg?400 |}} | {{ :guides:pics:text_mode_setup_vga.jpg?400 |}} | ||
guides/text_mode.txt · Last modified: 2020-08-28 23:13 by omolini
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