Int 60/AX=899Bh

AX = 899Bh
BX = function
0001h installation check
Return:
BX = 899Bh if installed
0002h ???
0003h ???.
???

Return:
???

Note: TTSR.EXE is found in FotoLook 2.09 (16-bit), which is available from agfa.com; it appears to provide DOS ASPI support !!!