Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!ucsd!sdcc6!ir230
From: ir230@sdcc6.ucsd.EDU (john wavrik)
Newsgroups: comp.sys.ibm.pc
Subject: DOS upgrade and SYS
Message-ID: <3689@sdcc6.ucsd.EDU>
Date: 22 Apr 88 06:34:04 GMT
Organization: University of California, San Diego
Lines: 23
Keywords: MS-DOS SYS


I recently installed minor upgrades to both my BIOS ROM and to the DOS in my 
computer. The new BIOS arrived several weeks before the DOS, so I was able to 
notice some bugs caused by the incompatibility.
 
 When the DOS upgrade arrived, I changed the attributes on the hidden files to 
 make them normal on both the hard disk and distribution disk, and I then 
 copied them from the distribution disk to the hard disk using COPY. I also 
 copied COMMAND.COM and all of the external command files which interested me. 
 A file comparison program showed that the copies were the same as on the 
 distribution disk. I then changed the attributes on the hidden files to what 
 they were originally. The bugs were still there. At this point, I remembered 
 the SYS command -- after I used SYS, everything was fine. 
  
  I'm curious as to what SYS does other than what I tried to do by hand. Isn't 
  the DOS determined (internally) by the two hidden IBMxxx.COM files and 
  COMMAND.COM? It's obvious that SYS is quicker -- but why is it essential?  Is 
  there something that Peter Norton didn't tell me?  As a further (potential) 
  problem, I find that the manual says that SYS will not work if the new system 
  is bigger than the old. What happens if I want to install DOS 3.3, rather than 
  just an upgrade of DOS 3.2, on a hard disk full of files? 
   
					  J J Wavrik
					  UCSD.