Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!dciem!nrcaer!cognos!brianc From: brianc@cognos.uucp (Brian Campbell) Newsgroups: comp.sys.ibm.pc Subject: Re: Updating DOS on a harddisk Message-ID: <1953@cognos.UUCP> Date: Mon, 7-Dec-87 14:24:14 EST Article-I.D.: cognos.1953 Posted: Mon Dec 7 14:24:14 1987 Date-Received: Sun, 13-Dec-87 00:43:10 EST References: <3418@ece-csc.UUCP> <63200007@convex> Reply-To: brianc@cognos.UUCP (Brian Campbell) Organization: Cognos Incorporated, Ottawa, Canada Lines: 60 In article <63200007@convex> cuddy@convex.UUCP writes: ! ! >> In article <3418@ece-csc.UUCP>, azk@ece-csc.UUCP (Anwer Kotob) writes: ! >> I have the following problem: In the course of updating from DOS 2.1 ! >> to DOS 3.1, I did the following: ! >> 1- erased IBMBIOS.COM and IBMDOS.COM from the harddisk, ! >> 2- did some more deleting and copying, It is the second step you did that probably killed your chances. SYS expects to copy the system files to the very beginning of the drive, and it wants to use the first two directory entries for the names of the system files. The extra copying and deleting you did may have affected this. ! >> 3- then tried to do: SYS C: ! >> ! >> what I got is a message saying that there is no room for the system on C: ! >>> Thanks in advance, ! >> ! >Boot up your system with DOS 3.1 from drive A, then transfer the ! >DOS's system files to C: by doing the followings: ! > ! >- From A, type: sys c: ! >after system files got transfer to C, do ! >- Copy all DOS files from floopy A to the directory in drive C ! >where you have all the DOS files of the old version. ! >- Check the "config.sys" and "autoexec.bat" to make sure all ! >device drivers and command syntax compatibility of the two versions. ! >- Make sure the new "command.com" is replaced if you keep it ! >in the root directory. ! ! WAIT!!!!! Don't take this advice.... when you change DOS versions, you MUST ! reformat the ENTIRE DISK. (a low level format is not needed, but a DOS level ! format is!) if you do not, you will screw yourself beyond all belief... ! you see, DOS 3.x uses 2k clusters (the smallest block of data that can be written) and DOS 2.x uses 8k clusters.. When you boot up with 3.x, if it even recognizes a hard disk with 2.x it will clobber it if you access the drive. ! ALSO: when you back up your hard disk, DO NOT back up the DOS 2.1 programs ! (DISKCOPY.COM, FORMAT.COM, CHKDSK.COM, .... etc. ) because although most of ! them check to see which DOS version you are currently using, some don't and ! try to read/write >2k clusters and WHAMMO! they clobber your drive... While I would agree that it is wise to reformat the entire disk with the new DOS format program, I do not agree with the reasoning here. Firstly, DOS 3.x can handle 2k, 4k or 8k clusters quite readily. Try formatting a 10 M partition with DOS 3.x and see what size cluster you get ... DOS 2.x wasn't the only version that used 8k clusters. I also do not know of any DOS utilities that depend on cluster size that do not check it specifically. I've been using 1k clusters, under DOS 3.1 and DOS 3.3, for months without any problems. ! REMEMBER: when upgrading DOS versions (major versions) you MUST reformat! ! I have been zapped by this: and have helped a great many customers with ! thier check books as a service tech @ a computer store to help them fix the ! problem/recover their data from this accident! This is still good advice ... -- Brian Campbell uucp: decvax!utzoo!dciem!nrcaer!cognos!brianc Cognos Incorporated mail: POB 9707, 3755 Riverside Drive, Ottawa, K1G 3Z4 (613) 738-1440 fido: (613) 731-2945 300/1200, sysop@1:163/8