PORTIBM PC Portable (uses same BIOS as XT) 0050-0052 - Olivetti M24 - 8530 SIO CHIP
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0065h"Olivetti"

0050  RW  8530 serial communications chip
Note:	At least MS-DOS 6 bypasses the initialization of serial devices if
	  it finds an Olivetti M24 machine with an 8630 SIO port present at
	  this address.
	An Olivetti-approved presence detection is to write 0Fh to port 50h
	  and check if bit 0 is still cleared when reading port 50h again.
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0066h, INT 14h/00h,INT 15h/C0h INTER 60 table 0515