[Ma-linux] Apprehensive about HW
donjr
djr1952 at hotpop.com
Tue Jan 30 17:23:11 EST 2007
On Tue, 2007-01-30 at 08:19 -0500, Johnson, Steve (NIH/OD/ORS) [E]
wrote:
> >> I thought it was the BIOS, but I could be wrong.
>
> My question on this was the capabilities of the chip in the keyboard.
> In other words, while it is easy explain how BIOS or the kernel
> could send morse code, are the Num Lock and Caps Lock lights
> controllable from the CPU, from the bus?
YES, each of the Num, Caps, Scroll lights can be turned ON or OFF
depending on what value you set the byte at memory address 40:17 to.
See: http://maven.smith.edu/~thiebaut/ArtOfAssembly/CH20/CH20-1.html
> I thought mode for those lights was simply in response to
> keyboard actions.
No see above.
> Explaining Morse code is easy because BIOS is basically
The rest someone else will have to handle.
--
--
Don E. Groves, Jr.
$ /usr/games/fortune :
Good night to spend with family, but avoid arguments with your mate's
new lover.
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