INT 7A - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. Personal Communications/3270 - INSTALLATION CHECK
	AX = FDCBh
Return: DX:AX -> PCS/3270 signature block if loaded (see #03839)


Format of Personal Communications/3270 signature block:
Offset	Size	Description	(Table 03839)
 04h	WORD	PCS/3270 signature (5741h)
 06h	WORD	version (0501h = PCS/3270 v1.0)