VIRTUAL DEVICE DRIVERS

Virtual Device Drivers for Windows, which Microsoft Corp, is actively 
encouraging hardware vendors to write, promise improved memory management
for DOS Sessions as well as performance boosts under Windows.

Already, at least one example of this technology is on the market: 
LaserMaster's WinPrint Manager, for use with the same company's
WinPrinters and WinJet add-ons for lasers.  It sets up virtual ports using
a VxD and is able to get control when data is sent to thoes ports from DOS
Sessions.

Also forthcoming is Microsoft's recently announced Windows for Workgroups,
which will provide peer to peer networking on systems with suitable hardware.
DOS sessions will get network support only through windows, but because
network support will load as a VxD, it will come at no sub 1 megabyte memory
cost.  With this technology being developed, we are likely to see some 
specially written VxD's that act like TSRs in DOS Sessions with little or no
memory cost.