Int 21 Fn DF07 - Software Carousel - Send Command To Memory Section [T]
AX = DF07h
BL = task number
CX = length of command (max 8 chars)
DS:SI -> command line
Return: AL = status
00h Carousel not running
01h successful
FFh unsucessful
AH = error code (01h,06h) (see #1501)
Note: the maximum length seems too small and may be a typo for 80 characters