USBASPI.sys (ver 2.06) is the ASPI manager for USB mass-storage devices 
(it assigns a logical unit number).  

NJ32DISK.sys (ver 1.06) is the ASPI disk driver for USB mass-storage 
devices (it assigns a DOS drive letter).  

These two USB 2.0 drivers allow USB mass-storage devices such as 
Thumb-drives (Jump-drives, AdSticks, etcetera) to be used with DOS.  
Please note that these devices must be connected during DOS bootup, 
or they will not later be recognized (I don't think anyone has yet 
bothered to write a DOS TSR that will allow hot-plugging USB devices 
the way you can do it in Ms-Windows).  

Run USBASPI before NJ32DISK (similar to the way you first run the 
cd-rom ASPI driver before running MSCDEX).  If USBASPI does not find 
any USB mass-storage devices on bootup, it will not load (and NJ32DISK 
will not assign any drive letters).  Drive letters assigned will come 
after the internal Floppy drive, Hard drive, and other bios established 
storage devices have been assigned drive letters.  

This driver will assign its USB drive letters before the CD/DVD gets 
assigned their drive letters (due to NJ32DISK being loaded in 
Config.sys wheras the CD/DVD MSCDEX driver is loaded in Autoexec.bat).  
Therefore to keep your CD/DVD drive letters consistant, 
it is suggested that you always boot with the USB mass-storage 
devices connected.  After a drive letter has been assigned, you can 
remove and replace the  mass-storage media in a similar fashion as you 
can remove and replace floppy diskettes (the cache may have to be 
refreshed to recognize the media change tho, just as you must often 
do with floppy diskettes).  

Note: With the recent availability of plug-in mass-storage devices 
(USB drives, Camera memory cards, external drives, etcetera), plus the 
ability to virtually swap letters via software, DOS drive lettering is 
becomming inconsistant.  It is therefore highly recommended that you 
use virtual paths without specifying drive letters whenever possible 
when you configure your application software.  

