Re: Linus' laptop and Num lock status

[Randy Dunlap]

On Sun, 18 Feb 2007 17:04:01 +0100 Jean Delvare wrote:

> On Thu, 15 Feb 2007 06:34:35 -0800, H. Peter Anvin wrote:
> > Jean Delvare wrote:
> > > On x86, the BIOS led state can be read from byte 0x97 the BIOS RAM. The
> > > BIOS RAM is mapped at 0x400 so all we need to do is to one byte from
> > > RAM (offset 0x497). This is how Suse's hwinfo does.
> > 
> > Perhaps that's what Suse does, but the proper address is 0x417.
> > 
> > 0x497 is the rarely-used LPT2 timeout counter.
> 
> Still, the information printed by hwinfo is correct, I've tested it
> myself. Is there some publicly available documentation about the x86
> BIOS RAM mapping?

Hilo,

0x40:0x17 is called "keyboard control" and
0x40:0x97 is called "keyboard LED flags" in the IBM Personal
System/2 and Personal Computer BIOS Interface Technical Reference,
Section 3: Data Areas and ROM Tables.

<internet_search> /bios data areas tables/ ::

http://heim.ifi.uio.no/~stanisls/helppc/bios_data_area.html
http://heim.ifi.uio.no/~stanisls/helppc/kb_flags.html

---
~Randy
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