User:Johnburger/Demo/BIOS/A20
From OSDev Wiki
< User:Johnburger | Demo
The A20 gate has a defined BIOS handler for it - but surprisingly it is not always implemented by BIOS manufacturers. This page in the Wiki describes the recommended sequence of steps to perform - this is Step 2.
Demo/BIOS/A20.inc
; ; BIOS/A20.inc ; ; These are the definitions for the BIOS A20 controller BIOS.A20.Int EQU 15h BIOS.A20.Fn EQU 24h BIOS.A20.Enable EQU 01h BIOS.A20.Disable EQU 00h