Intermec 6640 Technical Reference page 143

SECTION 4 Toolkit for the 6640 Computer
For this
example, the floppy disk drive is drive D:.
OK
" NOTE:
Do not use the C: drive as the destination directory as it will over-
write AUTOEXEC.BAT, MSDOS.SYS, and other system files.
6640 Mobile Computer Technical Reference 4-83