INT 21 U - OS/2 v2.0+ Virtual DOS MachineA special type of virtual machine provided by OS/2 version 2.0, in which a copy of MS-DOS or an MS-DOS compatible operating system (or even an incompatible 8086 operating system) is run and appears to have full control of the system. See also Virtual Machine, INT 21h Function 64h. - GET SESSION TITLE AH = 64h DX = 0002h (function number) CX = 636Ch (magic value, "cl") BX = 0000h (indicates special request) ES:DI -> 13-byte buffer for current title Return: buffer filled (single 00h if title never changed) Note: if CX is not 636Ch on entry, INT 21/AH=6Ch is invoked, because a bug in OS/2 1.x FAPI erroneously called AH=64h instead of AH=6Ch SeeAlso: AH=64h/DX=0000h,AH=64h/DX=0001h,INT 15/AH=12h/BH=05h