Found some docs in the /MSToolKit/ folder, excerpted here:
Still no hits when searching for “Mode Switcher Toolkit”?
Title: vbios library
Author: Robin Burgener
Date: Sept 12, 1997
This library contains functions to emulate a real-mode 80x86 processor.
This is accomplished in one of two ways, the opcodes are either
interpreted, executed in virtual mode (Neutrino ONLY) or executed
in real-mode (QNX 4 only).
With the interpreter, a.k.a. Emu86, all opcodes are interpreted and all
memory may be virtual, parts of the “real-mode” machine are overlayed into
the emulator’s memory space. This approach has allowed QNX to maintain
compatibility with the changing video card markets by using the video card
vendor’s video BIOS supplied with the video card instead of hard-coding
modeswitching code for every new video card. Although the primary
purpose of this is to interpret calls to int10h, many other
applications are possible.
Emu86 - The part of VBIOS that interprets 80x86 opcodes and performs
the operations on a virtualized memory space
VM86 - The part of VBIOS that uses either virtual mode under Neutrino or
real-mode under QNX4
Document Title: Building a Video Mode Switcher
Author : David Rempel and Pete Patterson
Filename : ModeSwitcher.doc
Location : MSToolkit/docs/
Date : October 25 1997
Building a Video Mode Switcher
This document covers the purpose of a QNX Video Mode Switcher (referred
to as QVMS or Mode Switcher from now on) in the QNX/Photon or Neutrino/Photon
environment, and how to go about making one for a specific video card.
It also gives a rundown of the libraries included in the Mode Switcher
Toolkit (MSTK) to help with the various commonalities of QVMS writing.