Lot of vintage IBM 5.25-inch floppy diskettes centered on IBM Operating System/2 (OS/2) Version 1.20, copyright International Business Machines Corp. 1981, 1989 with Microsoft Corp. copyright 1981-1989. The OS/2 set includes the Installation Diskette (57F1751), Diskette 1 (57F1754), Diskette 2 (57F1757), Diskette 3 (57F1760), Diskette 4 (57F1763) and Diskette 5 (57F1766), along with Presentation Manager Device Drivers Diskette 1 (57F1772) and Diskette 2 (64F0258). Also included are an IBM RT PC AIX Operating System Base System Program disk (92X1483, 2 of 5, copyright 1985, 1987) and a Banyan VINES 4.10(0) Site-Specific Patch CF-3 Platform PS/2 diskette (SPR#1002736, copyright 1991 Banyan Systems Inc.). These are classic 5.25 floppy disks in their original printed IBM and Banyan sleeves, a piece of early PC operating system history from the late 1980s and early 1990s.