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[kernel] Use himem.sys method to enable A20 for greater 8042 compatibility - #2798

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ghaerr merged 1 commit into
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Aug 5, 2026
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[kernel] Use himem.sys method to enable A20 for greater 8042 compatibility#2798
ghaerr merged 1 commit into
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@ghaerr

@ghaerr ghaerr commented Aug 5, 2026

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After research and discussion in #2790, this changes the A20 enable mechanism to use the method employed by DOS himem.sys, which should allow for more compatibility with the various implementations of the 8042 keyboard controller.

As also discussed in #2790, the BIOS Data Area location 40:96 bit 4 is checked to see whether an 101/102 enhanced keyboard is installed, and enables CAP_KBD_LEDS so that the LEDS are processed during keypresses.

@EC1842, can you please test this to verify it works on your hardware?

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ghaerr merged commit 640b21d into master Aug 5, 2026
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ghaerr deleted the a20 branch August 5, 2026 17:17
@EC1842

EC1842 commented Aug 6, 2026

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can you please test this to verify it works on your hardware?

I'm away from home right now, but I can check it in the next three days.

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2 participants