INT 28 - PCXDUMP v9.00+ - INSTALLATION CHECK

	AX = 9999h
Return: AX = AAAAh if installed
	    CX = version number * 100 (example: 03A2h = 930 = v9.30)
	    DL = interrupt used by the dump function (see #02553)
		(00h if call not available)
	    BX = CS of PCXDUMP's INT 28 handler (undocumented)
	    ES = segment of PCXDUMP's memory block (v9.30, undocumented)
Program: PCXDUMP is a shareware screen grabber saving in PCX format
Notes:	if DL<>00h a dump can be requested by calling INT DL as shown
	  below (the user can choose the interrupt number at installation
	  time); if DL=00h the dump function can be called only by hotkeys
	  (this is the default)