Category: other operating systems
INT 2F - DR DOS 6.0+ IBMBIO.COM - REGISTER ROOT OF UPPER MEMORY LINK
AX = 12FFh
BX = 0009h
DX = new value for root segment of upper memory link
Return: AX = 0000h if supported
Notes: the DX value is stored at offset 66h in SYSVARS (see INT 21h/AH=52h)
and offset 18h in the Novell DOS 7 internal variable table
(see INT 21/AX=4458h)
This API is provided by IBMBIO.COM for the initialization phase
of drivers loaded via DEVICE=/HIDEVICE=/DEVICEHIGH= directives and
is only available during these short time intervals. It is probably
initiated by the Novell DOS 7+ EMM386.EXE.
this function has apparently been supported since DR DOS 6.0 "Buxton"
for Novell DOS 7, ES:BX points at the internal variable table DRDAT,
but this may change in future releases