The far memory access method
In this section:
Far memory is the entire 1 Mbyte memory area with the constraint the each object must fit withing a 64 Kbytes page.
Examples
These examples access far memory in different ways:
mov es, byte3(x) ; Access the global variable x.
mov a, es:x
addw ax, #lwrd(y) ; Access an entry in the
movw hl, ax ; global array y.
mov es, byte3(y)
mov a, es:[hl]
mov a, es:[hl+2] ; Access through a pointer.