Category: DOS-based task switchers/multitaskers

INT 21 - CTask 2.0+ - INSTALLATION CHECK

	AX = 3000h
	BX = 1234h
	DS:DX -> 8-byte version string (DX < FFF0h) "CTask21",00h for v2.1-2.2
Return: AL = DOS major version
	AH = DOS minor version
	CX:BX -> Ctask global data block
Program: CTask is a multitasking kernel for C written by Thomas Wagner
Note:	if first eight bytes of returned data block equal eight bytes passed
	  in, CTask is resident