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tty mode explained

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Carlos Fenollosa 2014-09-29 11:54:35 +02:00
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02-bootsector-print/README.md
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@ -7,9 +7,10 @@ something on the screen. We will raise an interrupt for this.
On this example we are going to write each character of the "Hello"
word into the register `al` (lower part of `ax`), the bytes `0x0e`
into `ah` (the higher part of `ax`) and raise interrupt `0x10` which
tells the machine to print on screen the contents of `ax`.
is a general interrupt for video services.
`0x0e` on `ah` is necessary to indicate tty mode.
`0x0e` on `ah` tells the video interrupt that the actual function
we want to run is to 'write the contents of `al` in tty mode`.
We will set tty mode only once though in the real world we
cannot be sure that the contents of `ah` are constant. Some other