Hello, all: I was able to get my hands on the two DOS 1.0 disks. So, I spent a few minutes with Sourcer and a good hex editor in search of the DR copyright notice. I didn't find it. Maybe I misunderstood the timing of the message, but I thought that the 1.0 version of DOS contained copyright information from Digital Research and when IBM found out, they compelled MS to expunge it, resulting in the 1.1 version. The file dates are as follows: c:\>dir a: Volume in drive A is 3COM53_D1 Volume Serial Number is 11DC-3A5E Directory of A:\ 07/23/81 12:00a 1,920 IBMBIO.COM *** 08/04/81 12:00a 3,231 COMMAND.COM *** 08/13/81 12:00a 6,400 IBMDOS.COM *** 09/10/01 09:28a 66,235 COMMAND.LST 09/10/01 09:27a 4,374 IBMBIO.SDF 09/10/01 09:28a 143,874 IBMDOS.LST 09/10/01 09:28a 16,231 IBMDOS.SDF 09/10/01 09:27a 25,780 IBMBIO.LST 09/10/01 09:28a 10,141 COMMAND.SDF 9 File(s) 278,186 bytes 1,177,088 bytes free The files are all dated before the PC's release. I find it interesting that the file date for DOS proper was one week before the PC announcement. Microsoft tweaking until the last minute. IBMBIO contains only a revision mark and no copyright notice. IBMDOS contains a header common to all versions of DOS ("M;S<>=~KRAA") and no copyright notice. COMMAND contains a copyright message which is the one probably displayed upon execution: The IBM Personal Computer DOS Version 1.00 (C)Copyright IBM Corp 1981 Licensed Material - Program Property of IBM So, where did I go wrong?? Rich ========================== Richard A. Cini, Jr. Congress Financial Corporation 1133 Avenue of the Americas 30th Floor New York, NY 10036 (212) 545-4402 (212) 840-6259 (facsimile)