INT 2F - DR-DOS 6.0 TaskMAX - CONVERT TASK INDEX TO TASK ID
AX = 270Ah
DX = task index
Return: DX = task ID (FFFFh if index invalid)
Note:   task IDs stay constant, while indexes can change when other tasks are
deleted
SeeAlso: AX=270Bh

See also: 2F2701

2F270A - DR-DOS 6.0 TaskMAX - CONVERT TASK INDEX TO TASK ID