INT 21 - DoubleDOS - SET TIMESHARING PRIORITY
AH = E9h
AL = 00h visible program gets 70%, invisible gets 30% (default)
= 01h visible program gets 50%, invisible gets 50%
= 02h visible program gets 30%, invisible gets 70%
= 03h Top program gets 70%, bottom program gets 30%
= 04h Top program gets 30%, bottom program gets 70%
= 05h get current priority
Return: AL = priority setting
Note:   identical to AH=F9h
SeeAlso: AH=EBh"DoubleDOS",AH=F9h"DoubleDOS"

See also: 21EA

21E9 - DoubleDOS - SET TIMESHARING PRIORITY