USBASPI V2.20 MS-DOS Driver

Source
Operating System: MS-DOS
Panasonic USBASPI V2.20
This MS-DOS driver makes it possible to access your USB device under MS-DOS.
Supports USB (OHCI/UHCI) and High Speed USB (EHCI) external Mass Storage devices such as hard disk drives, CD/DVD-ROM, flash disks and flash cards attached via card-readers.
All major chipsets are supported (Intel/Sis/Via/nVidia)
Important notes: Hotplug is not supported. Attach your device BEFORE you power on the computer. Also, refrain from use of any intermediate hub devices while using this driver.
The following line is needed in your config.sys:

device=X:\USBASPI.SYS /w /v 

Where X:\ — full path to the driver.
Now MHDD can access your USB storage as SCSI device in ASPI mode.
Download link: USBASPI V2.20 MS-DOS Driver